# The LearningOnline Network with CAPA
# .helper XML handler to implement the LON-CAPA helper
#
# $Id: lonhelper.pm,v 1.160 2006/12/18 21:48:47 albertel Exp $
#
# Copyright Michigan State University Board of Trustees
#
# This file is part of the LearningOnline Network with CAPA (LON-CAPA).
#
# LON-CAPA is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# LON-CAPA is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with LON-CAPA; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#
# /home/httpd/html/adm/gpl.txt
#
# http://www.lon-capa.org/
#

=pod

=head1 NAME

lonhelper - implements helper framework

=head1 SYNOPSIS

lonhelper implements the helper framework for LON-CAPA, and provides
    many generally useful components for that framework.

Helpers are little programs which present the user with a sequence of
    simple choices, instead of one monolithic multi-dimensional
    choice. They are also referred to as "wizards", "druids", and
    other potentially trademarked or semantically-loaded words.

=head1 OVERVIEWX<lonhelper>

Helpers are well-established UI widgets that users
feel comfortable with. It can take a complicated multidimensional problem the
user has and turn it into a series of bite-sized one-dimensional questions.

For developers, helpers provide an easy way to bundle little bits of functionality
for the user, without having to write the tedious state-maintenence code.

Helpers are defined as XML documents, placed in the /home/httpd/html/adm/helpers 
directory and having the .helper file extension. For examples, see that directory.

All classes are in the Apache::lonhelper namespace.

=head1 lonhelper XML file formatX<lonhelper, XML file format>

A helper consists of a top-level <helper> tag which contains a series of states.
Each state contains one or more state elements, which are what the user sees, like
messages, resource selections, or date queries.

The helper tag is required to have one attribute, "title", which is the name
of the helper itself, such as "Parameter helper". The helper tag may optionally
have a "requiredpriv" attribute, specifying the priviledge a user must have
to use the helper, or get denied access. See loncom/auth/rolesplain.tab for
useful privs. Default is full access, which is often wrong!

=head2 State tags

State tags are required to have an attribute "name", which is the symbolic
name of the state and will not be directly seen by the user. The helper is
required to have one state named "START", which is the state the helper
will start with. By convention, this state should clearly describe what
the helper will do for the user, and may also include the first information
entry the user needs to do for the helper.

State tags are also required to have an attribute "title", which is the
human name of the state, and will be displayed as the header on top of 
the screen for the user.

State tags may also optionally have an attribute "help" which should be
the filename of a help file, this will add a blue ? to the title.

=head2 Example Helper Skeleton

An example of the tags so far:

 <helper title="Example Helper">
   <state name="START" title="Demonstrating the Example Helper">
     <!-- notice this is the START state the helper requires -->
     </state>
   <state name="GET_NAME" title="Enter Student Name">
     </state>
   </helper>

Of course this does nothing. In order for the helper to do something, it is
necessary to put actual elements into the helper. Documentation for each
of these elements follows.

=head1 Creating a Helper With Code, Not XML

In some situations, such as the printing helper (see lonprintout.pm), 
writing the helper in XML would be too complicated, because of scope 
issues or the fact that the code actually outweighs the XML. It is
possible to create a helper via code, though it is a little odd.

Creating a helper via code is more like issuing commands to create
a helper then normal code writing. For instance, elements will automatically
be added to the last state created, so it's important to create the 
states in the correct order.

First, create a new helper:

 use Apache::lonhelper;

 my $helper = Apache::lonhelper::new->("Helper Title");

Next you'll need to manually add states to the helper:

 Apache::lonhelper::state->new("STATE_NAME", "State's Human Title");

You don't need to save a reference to it because all elements up until
the next state creation will automatically be added to this state.

Elements are created by populating the $paramHash in 
Apache::lonhelper::paramhash. To prevent namespace issues, retrieve 
a reference to that has with getParamHash:

 my $paramHash = Apache::lonhelper::getParamHash();

You will need to do this for each state you create.

Populate the $paramHash with the parameters for the element you wish
to add next; the easiest way to find out what those entries are is
to read the code. Some common ones are 'variable' to record the variable
to store the results in, and NEXTSTATE to record a next state transition.

Then create your element:

 $paramHash->{MESSAGETEXT} = "This is a message.";
 Apache::lonhelper::message->new();

The creation will take the $paramHash and bless it into a
Apache::lonhelper::message object. To create the next element, you need
to get a reference to the new, empty $paramHash:

 $paramHash = Apache::lonhelper::getParamHash();

and you can repeat creating elements that way. You can add states
and elements as needed.

See lonprintout.pm, subroutine printHelper for an example of this, where
we dynamically add some states to prevent security problems, for instance.

Normally the machinery in the XML format is sufficient; dynamically 
adding states can easily be done by wrapping the state in a <condition>
tag. This should only be used when the code dominates the XML content,
the code is so complicated that it is difficult to get access to
all of the information you need because of scoping issues, or would-be <exec> or 
<eval> blocks using the {DATA} mechanism results in hard-to-read
and -maintain code. (See course.initialization.helper for a borderline
case.)

It is possible to do some of the work with an XML fragment parsed by
lonxml; again, see lonprintout.pm for an example. In that case it is 
imperative that you call B<Apache::lonhelper::registerHelperTags()>
before parsing XML fragments and B<Apache::lonhelper::unregisterHelperTags()>
when you are done. See lonprintout.pm for examples of this usage in the
printHelper subroutine.

=head2 Localization

The helper framework tries to handle as much localization as
possible. The text is always run through
Apache::lonlocal::normalize_string, so be sure to run the keys through
that function for maximum usefulness and robustness.

=cut

package Apache::lonhelper;
use Apache::Constants qw(:common);
use Apache::File;
use Apache::lonxml;
use Apache::lonlocal;
use Apache::lonnet;
use Apache::longroup;
use Apache::lonselstudent;
use LONCAPA;

# Register all the tags with the helper, so the helper can 
# push and pop them

my @helperTags;

sub register {
    my ($namespace, @tags) = @_;

    for my $tag (@tags) {
        push @helperTags, [$namespace, $tag];
    }
}

BEGIN {
    Apache::lonxml::register('Apache::lonhelper', 
                             ('helper'));
      register('Apache::lonhelper', ('state'));
}

# Since all helpers are only three levels deep (helper tag, state tag, 
# substate type), it's easier and more readble to explicitly track 
# those three things directly, rather then futz with the tag stack 
# every time.
my $helper;
my $state;
my $substate;
# To collect parameters, the contents of the subtags are collected
# into this paramHash, then passed to the element object when the 
# end of the element tag is located.
my $paramHash; 

# Note from Jeremy 5-8-2003: It is *vital* that the real handler be called
# as a subroutine from the handler, or very mysterious things might happen.
# I don't know exactly why, but it seems that the scope where the Apache
# server enters the perl handler is treated differently from the rest of
# the handler. This also seems to manifest itself in the debugger as entering
# the perl handler in seemingly random places (sometimes it starts in the
# compiling phase, sometimes in the handler execution phase where it runs
# the code and stepping into the "1;" the module ends with goes into the handler,
# sometimes starting directly with the handler); I think the cause is related.
# In the debugger, this means that breakpoints are ignored until you step into
# a function and get out of what must be a "faked up scope" in the Apache->
# mod_perl connection. In this code, it was manifesting itself in the existence
# of two separate file-scoped $helper variables, one set to the value of the
# helper in the helper constructor, and one referenced by the handler on the
# "$helper->process()" line. Using the debugger, one could actually
# see the two different $helper variables, as hashes at completely
# different addresses. The second was therefore never set, and was still
# undefined when I tried to call process on it.
# By pushing the "real handler" down into the "real scope", everybody except the 
# actual handler function directly below this comment gets the same $helper and
# everybody is happy.
# The upshot of all of this is that for safety when a handler is  using 
# file-scoped variables in LON-CAPA, the handler should be pushed down one 
# call level, as I do here, to ensure that the top-level handler function does
# not get a different file scope from the rest of the code.
sub handler {
    my $r = shift;
    return real_handler($r);
}

# For debugging purposes, one can send a second parameter into this
# function, the 'uri' of the helper you wish to have rendered, and
# call this from other handlers.
sub real_handler {
    my $r = shift;
    my $uri = shift;
    if (!defined($uri)) { $uri = $r->uri(); }
    $env{'request.uri'} = $uri;
    my $filename = '/home/httpd/html' . $uri;
    my $fh = Apache::File->new($filename);
    my $file;
    read $fh, $file, 100000000;


    # Send header, don't cache this page
    if ($env{'browser.mathml'}) {
	&Apache::loncommon::content_type($r,'text/xml');
    } else {
	&Apache::loncommon::content_type($r,'text/html');
    }
    $r->send_http_header;
    return OK if $r->header_only;
    $r->rflush();

    # Discard result, we just want the objects that get created by the
    # xml parsing
    &Apache::lonxml::xmlparse($r, 'helper', $file);

    my $allowed = $helper->allowedCheck();
    if (!$allowed) {
        $env{'user.error.msg'} = $env{'request.uri'}.':'.$helper->{REQUIRED_PRIV}.
            ":0:0:Permission denied to access this helper.";
        return HTTP_NOT_ACCEPTABLE;
    }

    $helper->process();

    $r->print($helper->display());
    return OK;
}

sub registerHelperTags {
    for my $tagList (@helperTags) {
        Apache::lonxml::register($tagList->[0], $tagList->[1]);
    }
}

sub unregisterHelperTags {
    for my $tagList (@helperTags) {
        Apache::lonxml::deregister($tagList->[0], $tagList->[1]);
    }
}

sub start_helper {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;

    if ($target ne 'helper') {
        return '';
    }

    registerHelperTags();

    Apache::lonhelper::helper->new($token->[2]{'title'}, $token->[2]{'requiredpriv'});
    return '';
}

sub end_helper {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
    
    if ($target ne 'helper') {
        return '';
    }

    unregisterHelperTags();

    return '';
}

sub start_state {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;

    if ($target ne 'helper') {
        return '';
    }

    Apache::lonhelper::state->new($token->[2]{'name'},
                                  $token->[2]{'title'},
				  $token->[2]{'help'});
    return '';
}

# Use this to get the param hash from other files.
sub getParamHash {
    return $paramHash;
}

# Use this to get the helper, if implementing elements in other files
# (like lonprintout.pm)
sub getHelper {
    return $helper;
}

# don't need this, so ignore it
sub end_state {
    return '';
}

1;

package Apache::lonhelper::helper;

use Digest::MD5 qw(md5_hex);
use HTML::Entities();
use Apache::loncommon;
use Apache::File;
use Apache::lonlocal;
use Apache::lonnet;
use LONCAPA;

sub new {
    my $proto = shift;
    my $class = ref($proto) || $proto;
    my $self = {};

    $self->{TITLE} = shift;
    $self->{REQUIRED_PRIV} = shift;
    
    # If there is a state from the previous form, use that. If there is no
    # state, use the start state parameter.
    if (defined $env{"form.CURRENT_STATE"})
    {
	$self->{STATE} = $env{"form.CURRENT_STATE"};
    }
    else
    {
	$self->{STATE} = "START";
    }

    $self->{TOKEN} = $env{'form.TOKEN'};
    # If a token was passed, we load that in. Otherwise, we need to create a 
    # new storage file
    # Tried to use standard Tie'd hashes, but you can't seem to take a 
    # reference to a tied hash and write to it. I'd call that a wart.
    if ($self->{TOKEN}) {
        # Validate the token before trusting it
        if ($self->{TOKEN} !~ /^[a-f0-9]{32}$/) {
            # Not legit. Return nothing and let all hell break loose.
            # User shouldn't be doing that!
            return undef;
        }

        # Get the hash.
        $self->{FILENAME} = $Apache::lonnet::tmpdir . md5_hex($self->{TOKEN}); # Note the token is not the literal file
        
        my $file = Apache::File->new($self->{FILENAME});
        my $contents = <$file>;

        # Now load in the contents
        for my $value (split (/&/, $contents)) {
            my ($name, $value) = split(/=/, $value);
            $value =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C", hex($1))/eg;
            $self->{VARS}->{$name} = $value;
        }

        $file->close();
    } else {
        # Only valid if we're just starting.
        if ($self->{STATE} ne 'START') {
            return undef;
        }
        # Must create the storage
        $self->{TOKEN} = md5_hex($env{'user.name'} . $env{'user.domain'} .
                                 time() . rand());
        $self->{FILENAME} = $Apache::lonnet::tmpdir . md5_hex($self->{TOKEN});
    }

    # OK, we now have our persistent storage.

    if (defined $env{"form.RETURN_PAGE"})
    {
	$self->{RETURN_PAGE} = $env{"form.RETURN_PAGE"};
    }
    else
    {
	$self->{RETURN_PAGE} = $ENV{REFERER};
    }

    $self->{STATES} = {};
    $self->{DONE} = 0;

    # Used by various helpers for various things; see lonparm.helper
    # for an example.
    $self->{DATA} = {};

    $helper = $self;

    # Establish the $paramHash
    $paramHash = {};

    bless($self, $class);
    return $self;
}

# Private function; returns a string to construct the hidden fields
# necessary to have the helper track state.
sub _saveVars {
    my $self = shift;
    my $result = "";
    $result .= '<input type="hidden" name="CURRENT_STATE" value="' .
        HTML::Entities::encode($self->{STATE},'<>&"') . "\" />\n";
    $result .= '<input type="hidden" name="TOKEN" value="' .
        $self->{TOKEN} . "\" />\n";
    $result .= '<input type="hidden" name="RETURN_PAGE" value="' .
        HTML::Entities::encode($self->{RETURN_PAGE},'<>&"') . "\" />\n";

    return $result;
}

# Private function: Create the querystring-like representation of the stored
# data to write to disk.
sub _varsInFile {
    my $self = shift;
    my @vars = ();
    for my $key (keys(%{$self->{VARS}})) {
        push(@vars, &escape($key) . '=' . &escape($self->{VARS}->{$key}));
    }
    return join ('&', @vars);
}

# Use this to declare variables.
# FIXME: Document this
sub declareVar {
    my $self = shift;
    my $var = shift;

    if (!defined($self->{VARS}->{$var})) {
        $self->{VARS}->{$var} = '';
    }

    my $envname = 'form.' . $var . '_forminput';
    if (defined($env{$envname})) {
        if (ref($env{$envname})) {
            $self->{VARS}->{$var} = join('|||', @{$env{$envname}});
        } else {
            $self->{VARS}->{$var} = $env{$envname};
        }
    }
}

sub allowedCheck {
    my $self = shift;

    if (!defined($self->{REQUIRED_PRIV})) { 
        return 1;
    }

    return Apache::lonnet::allowed($self->{REQUIRED_PRIV}, $env{'request.course.id'});
}

sub changeState {
    my $self = shift;
    $self->{STATE} = shift;
}

sub registerState {
    my $self = shift;
    my $state = shift;

    my $stateName = $state->name();
    $self->{STATES}{$stateName} = $state;
}

sub process {
    my $self = shift;

    # Phase 1: Post processing for state of previous screen (which is actually
    # the "current state" in terms of the helper variables), if it wasn't the 
    # beginning state.
    if ($self->{STATE} ne "START" || $env{"form.SUBMIT"} eq &mt("Next ->")) {
	my $prevState = $self->{STATES}{$self->{STATE}};
        $prevState->postprocess();
    }
    
    # Note, to handle errors in a state's input that a user must correct,
    # do not transition in the postprocess, and force the user to correct
    # the error.

    # Phase 2: Preprocess current state
    my $startState = $self->{STATE};
    my $state = $self->{STATES}->{$startState};
    
    # For debugging, print something here to determine if you're going
    # to an undefined state.
    if (!defined($state)) {
        return;
    }
    $state->preprocess();

    # Phase 3: While the current state is different from the previous state,
    # keep processing.
    while ( $startState ne $self->{STATE} && 
            defined($self->{STATES}->{$self->{STATE}}) )
    {
	$startState = $self->{STATE};
	$state = $self->{STATES}->{$startState};
	$state->preprocess();
    }

    return;
} 

# 1: Do the post processing for the previous state.
# 2: Do the preprocessing for the current state.
# 3: Check to see if state changed, if so, postprocess current and move to next.
#    Repeat until state stays stable.
# 4: Render the current state to the screen as an HTML page.
sub display {
    my $self = shift;

    my $state = $self->{STATES}{$self->{STATE}};

    my $result = "";

    if (!defined($state)) {
        $result = "<font color='#ff0000'>Error: state '$state' not defined!</font>";
        return $result;
    }

    # Phase 4: Display.
    my $stateTitle=&mt($state->title());
    my $stateHelp=     $state->help();
    my $browser_searcher_js = 
	'<script type="text/javascript">'."\n".
	&Apache::loncommon::browser_and_searcher_javascript().
	"\n".'</script>';

    $result .= &Apache::loncommon::start_page($self->{TITLE},
					      $browser_searcher_js);
    
    my $previous = HTML::Entities::encode(&mt("<- Previous"), '<>&"');
    my $next = HTML::Entities::encode(&mt("Next ->"), '<>&"');
    # FIXME: This should be parameterized, not concatenated - Jeremy


    if (!$state->overrideForm()) { $result.="<form name='helpform' method='POST'>"; }
    if ($stateHelp) {
	$stateHelp = &Apache::loncommon::help_open_topic($stateHelp);
    }
    $result .= <<HEADER;
        <table border="0" width='100%'><tr><td>
        <h2><i>$stateTitle</i>$stateHelp</h2>
HEADER

    $result .= "<table cellpadding='10' width='100%'><tr><td rowspan='2' valign='top'>";

    if (!$state->overrideForm()) {
        $result .= $self->_saveVars();
    }
    $result .= $state->render();

    $result .= "</td><td valign='top' align='right'>";

    # Warning: Copy and pasted from below, because it's too much trouble to 
    # turn this into a subroutine
    if (!$state->overrideForm()) {
        if ($self->{STATE} ne $self->{START_STATE}) {
            #$result .= '<input name="SUBMIT" type="submit" value="&lt;- Previous" />&nbsp;&nbsp;';
        }
        if ($self->{DONE}) {
            my $returnPage = $self->{RETURN_PAGE};
            $result .= "<a href=\"$returnPage\">" . &mt("End Helper") . "</a>";
        }
        else {
            $result .= '<nobr><input name="back" type="button" ';
            $result .= 'value="' . $previous . '" onclick="history.go(-1)" /> ';
            $result .= '<input name="SUBMIT" type="submit" value="' . $next . '" /></nobr>';
        }
    }

    $result .= "</td></tr><tr><td valign='bottom' align='right'>";

    # Warning: Copy and pasted from above, because it's too much trouble to 
    # turn this into a subroutine
    if (!$state->overrideForm()) {
        if ($self->{STATE} ne $self->{START_STATE}) {
            #$result .= '<input name="SUBMIT" type="submit" value="&lt;- Previous" />&nbsp;&nbsp;';
        }
        if ($self->{DONE}) {
            my $returnPage = $self->{RETURN_PAGE};
            $result .= "<a href=\"$returnPage\">" . &mt('End Helper') . "</a>";
        }
        else {
            $result .= '<nobr><input name="back" type="button" ';
            $result .= 'value="' . $previous . '" onclick="history.go(-1)" /> ';
            $result .= '<input name="SUBMIT" type="submit" value="' . $next . '" /></nobr>';
        }
    }

    #foreach my $key (keys %{$self->{VARS}}) {
    #    $result .= "|$key| -> " . $self->{VARS}->{$key} . "<br />";
    #}

    $result .= "</td></tr></table>";

    $result .= <<FOOTER;
              </td>
            </tr>
          </table>
        </form>
FOOTER

    $result .= &Apache::loncommon::end_page();
    # Handle writing out the vars to the file
    my $file = Apache::File->new('>'.$self->{FILENAME});
    print $file $self->_varsInFile();

    return $result;
}

1;

package Apache::lonhelper::state;

# States bundle things together and are responsible for compositing the
# various elements together. It is not generally necessary for users to
# use the state object directly, so it is not perldoc'ed.

# Basically, all the states do is pass calls to the elements and aggregate
# the results.

sub new {
    my $proto = shift;
    my $class = ref($proto) || $proto;
    my $self = {};

    $self->{NAME} = shift;
    $self->{TITLE} = shift;
    $self->{HELP} = shift;
    $self->{ELEMENTS} = [];

    bless($self, $class);

    $helper->registerState($self);

    $state = $self;

    return $self;
}

sub name {
    my $self = shift;
    return $self->{NAME};
}

sub title {
    my $self = shift;
    return $self->{TITLE};
}

sub help {
    my $self = shift;
    return $self->{HELP};
}

sub preprocess {
    my $self = shift;
    for my $element (@{$self->{ELEMENTS}}) {
        $element->preprocess();
    }
}

# FIXME: Document that all postprocesses must return a true value or
# the state transition will be overridden
sub postprocess {
    my $self = shift;

    # Save the state so we can roll it back if we need to.
    my $originalState = $helper->{STATE};
    my $everythingSuccessful = 1;

    for my $element (@{$self->{ELEMENTS}}) {
        my $result = $element->postprocess();
        if (!$result) { $everythingSuccessful = 0; }
    }

    # If not all the postprocesses were successful, override
    # any state transitions that may have occurred. It is the
    # responsibility of the states to make sure they have 
    # error handling in that case.
    if (!$everythingSuccessful) {
        $helper->{STATE} = $originalState;
    }
}

# Override the form if any element wants to.
# two elements overriding the form will make a mess, but that should
# be considered helper author error ;-)
sub overrideForm {
    my $self = shift;
    for my $element (@{$self->{ELEMENTS}}) {
        if ($element->overrideForm()) {
            return 1;
        }
    }
    return 0;
}

sub addElement {
    my $self = shift;
    my $element = shift;
    
    push @{$self->{ELEMENTS}}, $element;
}

sub render {
    my $self = shift;
    my @results = ();

    for my $element (@{$self->{ELEMENTS}}) {
        push @results, $element->render();
    }

    return join("\n", @results);
}

1;

package Apache::lonhelper::element;
# Support code for elements

=pod

=head1 Element Base Class

The Apache::lonhelper::element base class provides support for elements
and defines some generally useful tags for use in elements.

=head2 finalcode tagX<finalcode>

Each element can contain a "finalcode" tag that, when the special FINAL
helper state is used, will be executed, surrounded by "sub { my $helper = shift;"
and "}". It is expected to return a string describing what it did, which 
may be an empty string. See course initialization helper for an example. This is
generally intended for helpers like the course initialization helper, which consist
of several panels, each of which is performing some sort of bite-sized functionality.

=head2 defaultvalue tagX<defaultvalue>

Each element that accepts user input can contain a "defaultvalue" tag that,
when surrounded by "sub { my $helper = shift; my $state = shift; " and "}",
will form a subroutine that when called will provide a default value for
the element. How this value is interpreted by the element is specific to
the element itself, and possibly the settings the element has (such as 
multichoice vs. single choice for <choices> tags). 

This is also intended for things like the course initialization helper, where the
user is setting various parameters. By correctly grabbing current settings 
and including them into the helper, it allows the user to come back to the
helper later and re-execute it, without needing to worry about overwriting
some setting accidentally.

Again, see the course initialization helper for examples.

=head2 validator tagX<validator>

Some elements that accepts user input can contain a "validator" tag that,
when surrounded by "sub { my $helper = shift; my $state = shift; my $element = shift; my $val = shift " 
and "}", where "$val" is the value the user entered, will form a subroutine 
that when called will verify whether the given input is valid or not. If it 
is valid, the routine will return a false value. If invalid, the routine 
will return an error message to be displayed for the user.

Consult the documentation for each element to see whether it supports this 
tag.

=head2 getValue methodX<getValue (helper elements)>

If the element stores the name of the variable in a 'variable' member, which
the provided ones all do, you can retreive the value of the variable by calling
this method.

=cut

BEGIN {
    &Apache::lonhelper::register('Apache::lonhelper::element',
                                 ('nextstate', 'finalcode',
                                  'defaultvalue', 'validator'));
}

# Because we use the param hash, this is often a sufficent
# constructor
sub new {
    my $proto = shift;
    my $class = ref($proto) || $proto;
    my $self = $paramHash;
    bless($self, $class);

    $self->{PARAMS} = $paramHash;
    $self->{STATE} = $state;
    $state->addElement($self);
    
    # Ensure param hash is not reused
    $paramHash = {};

    return $self;
}   

sub start_nextstate {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;

    if ($target ne 'helper') {
        return '';
    }
    
    $paramHash->{NEXTSTATE} = &Apache::lonxml::get_all_text('/nextstate',
                                                             $parser);
    return '';
}

sub end_nextstate { return ''; }

sub start_finalcode {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;

    if ($target ne 'helper') {
        return '';
    }
    
    $paramHash->{FINAL_CODE} = &Apache::lonxml::get_all_text('/finalcode',
                                                             $parser);
    return '';
}

sub end_finalcode { return ''; }

sub start_defaultvalue {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;

    if ($target ne 'helper') {
        return '';
    }
    
    $paramHash->{DEFAULT_VALUE} = &Apache::lonxml::get_all_text('/defaultvalue',
                                                             $parser);
    $paramHash->{DEFAULT_VALUE} = 'sub { my $helper = shift; my $state = shift;' .
        $paramHash->{DEFAULT_VALUE} . '}';
    return '';
}

sub end_defaultvalue { return ''; }

# Validators may need to take language specifications
sub start_validator {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;

    if ($target ne 'helper') {
        return '';
    }
    
    $paramHash->{VALIDATOR} = &Apache::lonxml::get_all_text('/validator',
                                                             $parser);
    $paramHash->{VALIDATOR} = 'sub { my $helper = shift; my $state = shift; my $element = shift; my $val = shift;' .
        $paramHash->{VALIDATOR} . '}';
    return '';
}

sub end_validator { return ''; }

sub preprocess {
    return 1;
}

sub postprocess {
    return 1;
}

sub render {
    return '';
}

sub overrideForm {
    return 0;
}

sub getValue {
    my $self = shift;
    return $helper->{VARS}->{$self->{'variable'}};
}

1;

package Apache::lonhelper::message;

=pod

=head1 Elements

=head2 Element: messageX<message, helper element>

Message elements display their contents, and
transition directly to the state in the <nextstate> attribute. Example:

 <message nextstate='GET_NAME'>
   This is the <b>message</b> the user will see, 
                 <i>HTML allowed</i>.
   </message>

This will display the HTML message and transition to the 'nextstate' if
given. The HTML will be directly inserted into the helper, so if you don't
want text to run together, you'll need to manually wrap the message text
in <p> tags, or whatever is appropriate for your HTML.

Message tags do not add in whitespace, so if you want it, you'll need to add
it into states. This is done so you can inline some elements, such as 
the <date> element, right between two messages, giving the appearence that 
the <date> element appears inline. (Note the elements can not be embedded
within each other.)

This is also a good template for creating your own new states, as it has
very little code beyond the state template.

=head3 Localization

The contents of the message tag will be run through the
normalize_string function and that will be used as a call to &mt.

=cut

no strict;
@ISA = ("Apache::lonhelper::element");
use strict;
use Apache::lonlocal;

BEGIN {
    &Apache::lonhelper::register('Apache::lonhelper::message',
                              ('message'));
}

sub new {
    my $ref = Apache::lonhelper::element->new();
    bless($ref);
}

# CONSTRUCTION: Construct the message element from the XML
sub start_message {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;

    if ($target ne 'helper') {
        return '';
    }

    $paramHash->{MESSAGE_TEXT} = &mtn(&Apache::lonxml::get_all_text('/message',
                                                               $parser));

    if (defined($token->[2]{'nextstate'})) {
        $paramHash->{NEXTSTATE} = $token->[2]{'nextstate'};
    }
    return '';
}

sub end_message {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;

    if ($target ne 'helper') {
        return '';
    }
    Apache::lonhelper::message->new();
    return '';
}

sub render {
    my $self = shift;

    return &mtn($self->{MESSAGE_TEXT});
}
# If a NEXTSTATE was given, switch to it
sub postprocess {
    my $self = shift;
    if (defined($self->{NEXTSTATE})) {
        $helper->changeState($self->{NEXTSTATE});
    }

    return 1;
}
1;

package Apache::lonhelper::helpicon;

=pod

=head1 Elements

=head2 Element: helpiconX<helpicon, helper element>

Helpicon elements add a help icon at the current location.
Example:

   <helpicon file="Help">
     General Help
   </helpicon>

In this example will generate a help icon to the Help.hlp url with a
description of 'General Help'. The description is not required and if
left out (Example: <helpicon file="Help" /> only the icon will be
added.)

=head3 Localization

The description text will be run through the normalize_string function
and that will be used as a call to &mt.

=cut

no strict;
@ISA = ("Apache::lonhelper::element");
use strict;
use Apache::lonlocal;

BEGIN {
    &Apache::lonhelper::register('Apache::lonhelper::helpicon',
				 ('helpicon'));
}

sub new {
    my $ref = Apache::lonhelper::element->new();
    bless($ref);
}

# CONSTRUCTION: Construct the message element from the XML
sub start_helpicon {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;

    if ($target ne 'helper') {
        return '';
    }

    $paramHash->{HELP_TEXT} = &mtn(&Apache::lonxml::get_all_text('/helpicon',
								 $parser));

    $paramHash->{HELP_TEXT} =~s/^\s+//;
    $paramHash->{HELP_TEXT} =~s/\s+$//;

    if (defined($token->[2]{'file'})) {
        $paramHash->{HELP_FILE} = $token->[2]{'file'};
    }
    return '';
}

sub end_helpicon {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;

    if ($target ne 'helper') {
        return '';
    }
    Apache::lonhelper::helpicon->new();
    return '';
}

sub render {
    my $self = shift;

    my $text;
    if ( $self->{HELP_TEXT} ne '') {
	$text=&mtn($self->{HELP_TEXT});
    }

    return &Apache::loncommon::help_open_topic($self->{HELP_FILE},
					       $text);
}
sub postprocess {
    my $self = shift;
    if (defined($self->{NEXTSTATE})) {
        $helper->changeState($self->{NEXTSTATE});
    }

    return 1;
}

1;

package Apache::lonhelper::skip;

=pod

=head1 Elements

=head2 Element: skipX<skip>

The <skip> tag allows you define conditions under which the current state 
should be skipped over and define what state to skip to.

  <state name="SKIP">
    <skip>
       <clause>
         #some code that decides whether to skip the state or not
       </clause>
       <nextstate>FINISH</nextstate>
    </skip>
    <message nextstate="FINISH">A possibly skipped state</message>
  </state>

=cut

no strict;
@ISA = ("Apache::lonhelper::element");
use strict;

BEGIN {
    &Apache::lonhelper::register('Apache::lonhelper::skip',
				 ('skip'));
}

sub new {
    my $ref = Apache::lonhelper::element->new();
    bless($ref);
}

sub start_skip {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;

    if ($target ne 'helper') {
        return '';
    }
    # let <cluase> know what text to skip to
    $paramHash->{SKIPTAG}='/skip';
    return '';
}

sub end_skip {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;

    if ($target ne 'helper') {
        return '';
    }
    Apache::lonhelper::skip->new();
    return '';
}

sub render {
    my $self = shift;
    return '';
}
# If a NEXTSTATE is set, switch to it
sub preprocess {
    my ($self) = @_;

    if (defined($self->{NEXTSTATE})) {
        $helper->changeState($self->{NEXTSTATE});
    }

    return 1;
}

1;

package Apache::lonhelper::choices;

=pod

=head2 Element: choicesX<choices, helper element>

Choice states provide a single choice to the user as a text selection box.
A "choice" is two pieces of text, one which will be displayed to the user
(the "human" value), and one which will be passed back to the program
(the "computer" value). For instance, a human may choose from a list of
resources on disk by title, while your program wants the file name.

<choices> takes an attribute "variable" to control which helper variable
the result is stored in.

<choices> takes an attribute "multichoice" which, if set to a true
value, will allow the user to select multiple choices.

<choices> takes an attribute "allowempty" which, if set to a true 
value, will allow the user to select none of the choices without raising
an error message.

=head3 SUB-TAGS

<choices> can have the following subtags:X<choice, helper tag>

=over 4

=item * <nextstate>state_name</nextstate>: If given, this will cause the
      choice element to transition to the given state after executing.
      This will override the <nextstate> passed to <choices> (if any).

=item * <choice />: If the choices are static,
      this element will allow you to specify them. Each choice
      contains  attribute, "computer", as described above. The
      content of the tag will be used as the human label.
      For example,  
      <choice computer='234-12-7312'>Bobby McDormik</choice>.

<choice> can take a parameter "eval", which if set to
a true value, will cause the contents of the tag to be
evaluated as it would be in an <eval> tag; see <eval> tag
below.

<choice> may optionally contain a 'nextstate' attribute, which
will be the state transistioned to if the choice is made, if
the choice is not multichoice. This will override the nextstate
passed to the parent C<choices> tag.

<choice> may optionally contain a 'relatedvalue' attribute, which
if present will cause a text entry to appear to the right of the
selection.  The value of the relatedvalue attribute is a variable
into which the text entry will be stored e.g.:
<choice computer='numberprovided" relatedvalue="num">Type the number in:</choice>

<choice> may contain a relatededefault atribute which, if the
relatedvalue attribute is present will be the initial value of the input
box.

=back

To create the choices programmatically, either wrap the choices in 
<condition> tags (prefered), or use an <exec> block inside the <choice>
tag. Store the choices in $state->{CHOICES}, which is a list of list
references, where each list has three strings. The first is the human
name, the second is the computer name. and the third is the option
next state. For example:

 <exec>
    for (my $i = 65; $i < 65 + 26; $i++) {
        push @{$state->{CHOICES}}, [chr($i), $i, 'next'];
    }
 </exec>

This will allow the user to select from the letters A-Z (in ASCII), while
passing the ASCII value back into the helper variables, and the state
will in all cases transition to 'next'.

You can mix and match methods of creating choices, as long as you always 
"push" onto the choice list, rather then wiping it out. (You can even 
remove choices programmatically, but that would probably be bad form.)

=head3 defaultvalue support

Choices supports default values both in multichoice and single choice mode.
In single choice mode, have the defaultvalue tag's function return the 
computer value of the box you want checked. If the function returns a value
that does not correspond to any of the choices, the default behavior of selecting
the first choice will be preserved.

For multichoice, return a string with the computer values you want checked,
delimited by triple pipes. Note this matches how the result of the <choices>
tag is stored in the {VARS} hash.

=cut

no strict;
@ISA = ("Apache::lonhelper::element");
use strict;
use Apache::lonlocal;
use Apache::lonnet;

BEGIN {
    &Apache::lonhelper::register('Apache::lonhelper::choices',
                              ('choice', 'choices'));
}

sub new {
    my $ref = Apache::lonhelper::element->new();
    bless($ref);
}

# CONSTRUCTION: Construct the message element from the XML
sub start_choices {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;

    if ($target ne 'helper') {
        return '';
    }

    # Need to initialize the choices list, so everything can assume it exists
    $paramHash->{'variable'} = $token->[2]{'variable'} if (!defined($paramHash->{'variable'}));
    $helper->declareVar($paramHash->{'variable'});
    $paramHash->{'multichoice'} = $token->[2]{'multichoice'};
    $paramHash->{'allowempty'} = $token->[2]{'allowempty'};
    $paramHash->{CHOICES} = [];
    return '';
}

sub end_choices {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;

    if ($target ne 'helper') {
        return '';
    }
    Apache::lonhelper::choices->new();
    return '';
}

sub start_choice {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;

    if ($target ne 'helper') {
        return '';
    }

    my $computer = $token->[2]{'computer'};
    my $human = &mt(&Apache::lonxml::get_all_text('/choice',
                                              $parser));
    my $nextstate  = $token->[2]{'nextstate'};
    my $evalFlag   = $token->[2]{'eval'};
    my $relatedVar = $token->[2]{'relatedvalue'}; 
    my $relatedDefault = $token->[2]{'relateddefault'};
    push @{$paramHash->{CHOICES}}, [&mtn($human), $computer, $nextstate, 
                                    $evalFlag, $relatedVar, $relatedDefault];
    return '';
}

sub end_choice {
    return '';
}

{
    # used to generate unique id attributes for <input> tags. 
    # internal use only.
    my $id = 0;
    sub new_id { return $id++; }
}

sub render {
    my $self = shift;
    my $var = $self->{'variable'};
    my $buttons = '';
    my $result = '';

    if ($self->{'multichoice'}) {
        $result .= <<SCRIPT;
<script type="text/javascript">
// <!--
    function checkall(value, checkName) {
	for (i=0; i<document.forms.helpform.elements.length; i++) {
            ele = document.forms.helpform.elements[i];
            if (ele.name == checkName + '_forminput') {
                document.forms.helpform.elements[i].checked=value;
            }
        }
    }
// -->
</script>
SCRIPT
    }

    # Only print "select all" and "unselect all" if there are five or
    # more choices; fewer then that and it looks silly.
    if ($self->{'multichoice'} && scalar(@{$self->{CHOICES}}) > 4) {
        my %lt=&Apache::lonlocal::texthash(
			'sa'  => "Select All",
		        'ua'  => "Unselect All");
        $buttons = <<BUTTONS;
<br />
<input type="button" onclick="checkall(true, '$var')" value="$lt{'sa'}" />
<input type="button" onclick="checkall(false, '$var')" value="$lt{'ua'}" />
<br />&nbsp;
BUTTONS
    }

    if (defined $self->{ERROR_MSG}) {
        $result .= '<br /><font color="#FF0000">' . $self->{ERROR_MSG} . '</font><br />';
    }

    $result .= $buttons;
    
    $result .= "<table>\n\n";

    my %checkedChoices;
    my $checkedChoicesFunc;

    if (defined($self->{DEFAULT_VALUE})) {
        $checkedChoicesFunc = eval ($self->{DEFAULT_VALUE});
        die 'Error in default value code for variable ' . 
            $self->{'variable'} . ', Perl said: ' . $@ if $@;
    } else {
        $checkedChoicesFunc = sub { return ''; };
    }

    # Process which choices should be checked.
    if ($self->{'multichoice'}) {
        for my $selectedChoice (split(/\|\|\|/, (&$checkedChoicesFunc($helper, $self)))) {
            $checkedChoices{$selectedChoice} = 1;
        }
    } else {
        # single choice
        my $selectedChoice = &$checkedChoicesFunc($helper, $self);
        
        my $foundChoice = 0;
        
        # check that the choice is in the list of choices.
        for my $choice (@{$self->{CHOICES}}) {
            if ($choice->[1] eq $selectedChoice) {
                $checkedChoices{$choice->[1]} = 1;
                $foundChoice = 1;
            }
        }
        
        # If we couldn't find the choice, pick the first one 
        if (!$foundChoice) {
            $checkedChoices{$self->{CHOICES}->[0]->[1]} = 1;
        }
    }

    my $type = "radio";
    if ($self->{'multichoice'}) { $type = 'checkbox'; }
    foreach my $choice (@{$self->{CHOICES}}) {
        my $id = &new_id();
        $result .= "<tr>\n<td width='20'>&nbsp;</td>\n";
        $result .= "<td valign='top'><input type='$type' name='${var}_forminput'"
            . " value='" . 
            HTML::Entities::encode($choice->[1],"<>&\"'") 
            . "'";
        if ($checkedChoices{$choice->[1]}) {
            $result .= " checked='checked' ";
        }
        $result .= qq{id="id$id"};
        my $choiceLabel = $choice->[0];
        if ($choice->[3]) {  # if we need to evaluate this choice
            $choiceLabel = "sub { my $helper = shift; my $state = shift;" .
                $choiceLabel . "}";
            $choiceLabel = eval($choiceLabel);
            $choiceLabel = &$choiceLabel($helper, $self);
        }
        $result .= "/></td><td> ".qq{<label for="id$id">}.
            $choiceLabel. "</label></td>";
	if ($choice->[4]) {
	    $result .='<td><input type="text" size="5" name="'
		.$choice->[4].'_forminput" value="'
                .$choice->[5].'" /></td>';
	}
	$result .= "</tr>\n";
    }
    $result .= "</table>\n\n\n";
    $result .= $buttons;

    return $result;
}

# If a NEXTSTATE was given or a nextstate for this choice was
# given, switch to it
sub postprocess {
    my $self = shift;
    my $chosenValue = $env{'form.' . $self->{'variable'} . '_forminput'};

    if (!defined($chosenValue) && !$self->{'allowempty'}) {
        $self->{ERROR_MSG} = 
	    &mt("You must choose one or more choices to continue.");
        return 0;
    }

    if (ref($chosenValue)) {
        $helper->{VARS}->{$self->{'variable'}} = join('|||', @$chosenValue);
    }

    if (defined($self->{NEXTSTATE})) {
        $helper->changeState($self->{NEXTSTATE});
    }
    
    foreach my $choice (@{$self->{CHOICES}}) {
        if ($choice->[1] eq $chosenValue) {
            if (defined($choice->[2])) {
                $helper->changeState($choice->[2]);
            }
        }
	if ($choice->[4]) {
	    my $varname = $choice->[4];
	    $helper->{'VARS'}->{$varname} = $env{'form.'."${varname}_forminput"};
	}
    }
    return 1;
}
1;

package Apache::lonhelper::dropdown;

=pod

=head2 Element: dropdownX<dropdown, helper tag>

A drop-down provides a drop-down box instead of a radio button
box. Because most people do not know how to use a multi-select
drop-down box, that option is not allowed. Otherwise, the arguments
are the same as "choices", except "allowempty" is also meaningless.

<dropdown> takes an attribute "variable" to control which helper variable
the result is stored in.

=head3 SUB-TAGS

<choice>, which acts just as it does in the "choices" element.

=cut

# This really ought to be a sibling class to "choice" which is itself
# a child of some abstract class.... *shrug*

no strict;
@ISA = ("Apache::lonhelper::element");
use strict;
use Apache::lonlocal;
use Apache::lonnet;

BEGIN {
    &Apache::lonhelper::register('Apache::lonhelper::dropdown',
                              ('dropdown'));
}

sub new {
    my $ref = Apache::lonhelper::element->new();
    bless($ref);
}

# CONSTRUCTION: Construct the message element from the XML
sub start_dropdown {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;

    if ($target ne 'helper') {
        return '';
    }

    # Need to initialize the choices list, so everything can assume it exists
    $paramHash->{'variable'} = $token->[2]{'variable'} if (!defined($paramHash->{'variable'}));
    $helper->declareVar($paramHash->{'variable'});
    $paramHash->{CHOICES} = [];
    return '';
}

sub end_dropdown {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;

    if ($target ne 'helper') {
        return '';
    }
    Apache::lonhelper::dropdown->new();
    return '';
}

sub render {
    my $self = shift;
    my $var = $self->{'variable'};
    my $result = '';

    if (defined $self->{ERROR_MSG}) {
        $result .= '<br /><font color="#FF0000">' . $self->{ERROR_MSG} . '</font><br />';
    }

    my %checkedChoices;
    my $checkedChoicesFunc;

    if (defined($self->{DEFAULT_VALUE})) {
        $checkedChoicesFunc = eval ($self->{DEFAULT_VALUE});
        die 'Error in default value code for variable ' . 
            $self->{'variable'} . ', Perl said: ' . $@ if $@;
    } else {
        $checkedChoicesFunc = sub { return ''; };
    }

    # single choice
    my $selectedChoice = &$checkedChoicesFunc($helper, $self);
    
    my $foundChoice = 0;
    
    # check that the choice is in the list of choices.
    for my $choice (@{$self->{CHOICES}}) {
	if ($choice->[1] eq $selectedChoice) {
	    $checkedChoices{$choice->[1]} = 1;
	    $foundChoice = 1;
	}
    }
    
    # If we couldn't find the choice, pick the first one 
    if (!$foundChoice) {
	$checkedChoices{$self->{CHOICES}->[0]->[1]} = 1;
    }

    $result .= "<select name='${var}_forminput'>\n";
    foreach my $choice (@{$self->{CHOICES}}) {
        $result .= "<option value='" . 
            HTML::Entities::encode($choice->[1],"<>&\"'") 
            . "'";
        if ($checkedChoices{$choice->[1]}) {
            $result .= " selected='selected' ";
        }
        my $choiceLabel = $choice->[0];
        if ($choice->[4]) {  # if we need to evaluate this choice
            $choiceLabel = "sub { my $helper = shift; my $state = shift;" .
                $choiceLabel . "}";
            $choiceLabel = eval($choiceLabel);
            $choiceLabel = &$choiceLabel($helper, $self);
        }
        $result .= ">" . &mtn($choiceLabel) . "</option>\n";
    }
    $result .= "</select>\n";

    return $result;
}

# If a NEXTSTATE was given or a nextstate for this choice was
# given, switch to it
sub postprocess {
    my $self = shift;
    my $chosenValue = $env{'form.' . $self->{'variable'} . '_forminput'};

    if (!defined($chosenValue) && !$self->{'allowempty'}) {
        $self->{ERROR_MSG} = "You must choose one or more choices to" .
            " continue.";
        return 0;
    }

    if (defined($self->{NEXTSTATE})) {
        $helper->changeState($self->{NEXTSTATE});
    }
    
    foreach my $choice (@{$self->{CHOICES}}) {
        if ($choice->[1] eq $chosenValue) {
            if (defined($choice->[2])) {
                $helper->changeState($choice->[2]);
            }
        }
    }
    return 1;
}
1;

package Apache::lonhelper::date;

=pod

=head2 Element: dateX<date, helper element>

Date elements allow the selection of a date with a drop down list.

Date elements can take two attributes:

=over 4

=item * B<variable>: The name of the variable to store the chosen
        date in. Required.

=item * B<hoursminutes>: If a true value, the date will show hours
        and minutes, as well as month/day/year. If false or missing,
        the date will only show the month, day, and year.

=back

Date elements contain only an option <nextstate> tag to determine
the next state.

Example:

 <date variable="DUE_DATE" hoursminutes="1">
   <nextstate>choose_why</nextstate>
   </date>

=cut

no strict;
@ISA = ("Apache::lonhelper::element");
use strict;
use Apache::lonlocal; # A localization nightmare
use Apache::lonnet;
use Time::localtime;

BEGIN {
    &Apache::lonhelper::register('Apache::lonhelper::date',
                              ('date'));
}

# Don't need to override the "new" from element
sub new {
    my $ref = Apache::lonhelper::element->new();
    bless($ref);
}

my @months = ("January", "February", "March", "April", "May", "June", "July",
	      "August", "September", "October", "November", "December");

# CONSTRUCTION: Construct the message element from the XML
sub start_date {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;

    if ($target ne 'helper') {
        return '';
    }

    $paramHash->{'variable'} = $token->[2]{'variable'};
    $helper->declareVar($paramHash->{'variable'});
    $paramHash->{'hoursminutes'} = $token->[2]{'hoursminutes'};
    $paramHash->{'anytime'} = $token->[2]{'anytime'};
}

sub end_date {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;

    if ($target ne 'helper') {
        return '';
    }
    Apache::lonhelper::date->new();
    return '';
}

sub render {
    my $self = shift;
    my $result = "";
    my $var = $self->{'variable'};

    my $date;

    my $time=time;
    my ($anytime,$onclick);


    # first check VARS for a valid new value from the user
    # then check DEFAULT_VALUE for a valid default time value
    # otherwise pick now as reasonably good time

    if (defined($helper->{VARS}{$var})
	&&  $helper->{VARS}{$var} > 0) {
	$date = localtime($helper->{VARS}{$var});
    } elsif (defined($self->{DEFAULT_VALUE})) {
        my $valueFunc = eval($self->{DEFAULT_VALUE});
        die('Error in default value code for variable ' . 
            $self->{'variable'} . ', Perl said: ' . $@) if $@;
        $time = &$valueFunc($helper, $self);
	if (lc($time) eq 'anytime') {
	    $anytime=1;
	    $date = localtime(time);
	    $date->min(0);
	} elsif (defined($time) && $time ne 0) {
	    $date = localtime($time);
	} else {
	    # leave date undefined so it'll default to now
	}
    }

    if (!defined($date)) {
	$date = localtime(time);
	$date->min(0);
    }

    if ($anytime) {
	$onclick = "onclick=\"javascript:updateCheck(this.form,'${var}anytime',false)\"";
    }
    # Default date: The current hour.

    if (defined $self->{ERROR_MSG}) {
        $result .= '<font color="#FF0000">' . $self->{ERROR_MSG} . '</font><br /><br />';
    }

    # Month
    my $i;
    $result .= "<select $onclick name='${var}month'>\n";
    for ($i = 0; $i < 12; $i++) {
        if ($i == $date->mon) {
            $result .= "<option value='$i' selected='selected'>";
        } else {
            $result .= "<option value='$i'>";
        }
        $result .= &mt($months[$i]) . "</option>\n";
    }
    $result .= "</select>\n";

    # Day
    $result .= "<select $onclick name='${var}day'>\n";
    for ($i = 1; $i < 32; $i++) {
        if ($i == $date->mday) {
            $result .= '<option selected="selected">';
        } else {
            $result .= '<option>';
        }
        $result .= "$i</option>\n";
    }
    $result .= "</select>,\n";

    # Year
    $result .= "<select $onclick name='${var}year'>\n";
    for ($i = 2000; $i < 2030; $i++) { # update this after 64-bit dates
        if ($date->year + 1900 == $i) {
            $result .= "<option selected='selected'>";
        } else {
            $result .= "<option>";
        }
        $result .= "$i</option>\n";
    }
    $result .= "</select>,\n";

    # Display Hours and Minutes if they are called for
    if ($self->{'hoursminutes'}) {
	# This needs parameterization for times.
	my $am = &mt('a.m.');
	my $pm = &mt('p.m.');
        # Build hour
        $result .= "<select $onclick name='${var}hour'>\n";
        $result .= "<option " . ($date->hour == 0 ? 'selected="selected" ':'') .
            " value='0'>" . &mt('midnight') . "</option>\n";
        for ($i = 1; $i < 12; $i++) {
            if ($date->hour == $i) {
                $result .= "<option selected='selected' value='$i'>$i $am</option>\n";
            } else {
                $result .= "<option value='$i'>$i $am</option>\n";
            }
        }
        $result .= "<option " . ($date->hour == 12 ? 'selected="selected" ':'') .
            " value='12'>" . &mt('noon') . "</option>\n";
        for ($i = 13; $i < 24; $i++) {
            my $printedHour = $i - 12;
            if ($date->hour == $i) {
                $result .= "<option selected='selected' value='$i'>$printedHour $pm</option>\n";
            } else {
                $result .= "<option value='$i'>$printedHour $pm</option>\n";
            }
        }

        $result .= "</select> :\n";

        $result .= "<select $onclick name='${var}minute'>\n";
	my $selected=0;
        for my $i ((0,15,30,45,59,undef,0..59)) {
            my $printedMinute = $i;
            if (defined($i) && $i < 10) {
                $printedMinute = "0" . $printedMinute;
            }
            if (!$selected && $date->min == $i) {
                $result .= "<option selected='selected'>";
		$selected=1;
            } else {
                $result .= "<option>";
            }
            $result .= "$printedMinute</option>\n";
        }
        $result .= "</select>\n";
    }
    if ($self->{'anytime'}) {
	$result.=(<<CHECK);
<script type="text/javascript">
// <!--
    function updateCheck(form,name,value) {
	var checkbox=form[name];
	checkbox.checked = value;
    }
// -->
</script>
CHECK
	$result.="&nbsp;or&nbsp;<label><input type='checkbox' ";
	if ($anytime) {
	    $result.=' checked="checked" '
	}
	$result.="name='${var}anytime'/>".&mt('Any time').'</label>'
    }
    return $result;

}
# If a NEXTSTATE was given, switch to it
sub postprocess {
    my $self = shift;
    my $var = $self->{'variable'};
    if ($env{'form.' . $var . 'anytime'}) {
	$helper->{VARS}->{$var} = undef;
    } else {
	my $month = $env{'form.' . $var . 'month'}; 
	my $day = $env{'form.' . $var . 'day'}; 
	my $year = $env{'form.' . $var . 'year'}; 
	my $min = 0; 
	my $hour = 0;
	if ($self->{'hoursminutes'}) {
	    $min = $env{'form.' . $var . 'minute'};
	    $hour = $env{'form.' . $var . 'hour'};
	}

	my $chosenDate;
	eval {$chosenDate = Time::Local::timelocal(0, $min, $hour, $day, $month, $year);};
	my $error = $@;

	# Check to make sure that the date was not automatically co-erced into a 
	# valid date, as we want to flag that as an error
	# This happens for "Feb. 31", for instance, which is coerced to March 2 or
	# 3, depending on if it's a leap year
	my $checkDate = localtime($chosenDate);
	
	if ($error || $checkDate->mon != $month || $checkDate->mday != $day ||
	    $checkDate->year + 1900 != $year) {
	    unless (Apache::lonlocal::current_language()== ~/^en/) {
		$self->{ERROR_MSG} = &mt("Invalid date entry");
		return 0;
	    }
	    # LOCALIZATION FIXME: Needs to be parameterized
	    $self->{ERROR_MSG} = "Can't use " . $months[$month] . " $day, $year as a "
		. "date because it doesn't exist. Please enter a valid date.";

	    return 0;
	}
	$helper->{VARS}->{$var} = $chosenDate;
    }

    if (defined($self->{VALIDATOR})) {
	my $validator = eval($self->{VALIDATOR});
	die 'Died during evaluation of validator code; Perl said: ' . $@ if $@;
	my $invalid = &$validator($helper, $state, $self, $self->getValue());
	if ($invalid) {
	    $self->{ERROR_MSG} = $invalid;
	    return 0;
	}
    }

    if (defined($self->{NEXTSTATE})) {
        $helper->changeState($self->{NEXTSTATE});
    }

    return 1;
}
1;

package Apache::lonhelper::resource;

=pod

=head2 Element: resourceX<resource, helper element>

<resource> elements allow the user to select one or multiple resources
from the current course. You can filter out which resources they can view,
and filter out which resources they can select. The course will always
be displayed fully expanded, because of the difficulty of maintaining
selections across folder openings and closings. If this is fixed, then
the user can manipulate the folders.

<resource> takes the standard variable attribute to control what helper
variable stores the results. It also takes a "multichoice"X<multichoice> attribute,
which controls whether the user can select more then one resource. The 
"toponly" attribute controls whether the resource display shows just the
resources in that sequence, or recurses into all sub-sequences, defaulting
to false. The "suppressEmptySequences" attribute reflects the 
suppressEmptySequences argument to the render routine, which will cause
folders that have all of their contained resources filtered out to also
be filtered out. The 'addstatus' attribute, if true, will add the icon
and long status display columns to the display. The 'addparts'
attribute will add in a part selector beside problems that have more
than 1 part.

=head3 SUB-TAGS

=over 4

=item * <filterfunc>X<filterfunc>: If you want to filter what resources are displayed
  to the user, use a filter func. The <filterfunc> tag should contain
  Perl code that when wrapped with "sub { my $res = shift; " and "}" is 
  a function that returns true if the resource should be displayed, 
  and false if it should be skipped. $res is a resource object. 
  (See Apache::lonnavmaps documentation for information about the 
  resource object.)

=item * <choicefunc>X<choicefunc>: Same as <filterfunc>, except that controls whether
  the given resource can be chosen. (It is almost always a good idea to
  show the user the folders, for instance, but you do not always want to 
  let the user select them.)

=item * <nextstate>: Standard nextstate behavior.

=item * <valuefunc>X<valuefunc>: This function controls what is returned by the resource
  when the user selects it. Like filterfunc and choicefunc, it should be
  a function fragment that when wrapped by "sub { my $res = shift; " and
  "}" returns a string representing what you want to have as the value. By
  default, the value will be the resource ID of the object ($res->{ID}).

=item * <mapurl>X<mapurl>: If the URL of a map is given here, only that map
  will be displayed, instead of the whole course. If the attribute
  "evaluate" is given and is true, the contents of the mapurl will be
  evaluated with "sub { my $helper = shift; my $state = shift;" and
  "}", with the return value used as the mapurl.

=back

=cut

no strict;
@ISA = ("Apache::lonhelper::element");
use strict;
use Apache::lonnet;

BEGIN {
    &Apache::lonhelper::register('Apache::lonhelper::resource',
                              ('resource', 'filterfunc', 
                               'choicefunc', 'valuefunc',
                               'mapurl','option'));
}

sub new {
    my $ref = Apache::lonhelper::element->new();
    bless($ref);
}

# CONSTRUCTION: Construct the message element from the XML
sub start_resource {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;

    if ($target ne 'helper') {
        return '';
    }

    $paramHash->{'variable'} = $token->[2]{'variable'};
    $helper->declareVar($paramHash->{'variable'});
    $paramHash->{'multichoice'} = $token->[2]{'multichoice'};
    $paramHash->{'suppressEmptySequences'} = $token->[2]{'suppressEmptySequences'};
    $paramHash->{'toponly'} = $token->[2]{'toponly'};
    $paramHash->{'addstatus'} = $token->[2]{'addstatus'};
    $paramHash->{'addparts'} = $token->[2]{'addparts'};
    if ($paramHash->{'addparts'}) {
	$helper->declareVar($paramHash->{'variable'}.'_part');
    }
    $paramHash->{'closeallpages'} = $token->[2]{'closeallpages'};
    return '';
}

sub end_resource {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;

    if ($target ne 'helper') {
        return '';
    }
    if (!defined($paramHash->{FILTER_FUNC})) {
        $paramHash->{FILTER_FUNC} = sub {return 1;};
    }
    if (!defined($paramHash->{CHOICE_FUNC})) {
        $paramHash->{CHOICE_FUNC} = sub {return 1;};
    }
    if (!defined($paramHash->{VALUE_FUNC})) {
        $paramHash->{VALUE_FUNC} = sub {my $res = shift; return $res->{ID}; };
    }
    Apache::lonhelper::resource->new();
    return '';
}

sub start_filterfunc {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;

    if ($target ne 'helper') {
        return '';
    }

    my $contents = Apache::lonxml::get_all_text('/filterfunc',
                                                $parser);
    $contents = 'sub { my $res = shift; ' . $contents . '}';
    $paramHash->{FILTER_FUNC} = eval $contents;
}

sub end_filterfunc { return ''; }

sub start_choicefunc {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;

    if ($target ne 'helper') {
        return '';
    }

    my $contents = Apache::lonxml::get_all_text('/choicefunc',
                                                $parser);
    $contents = 'sub { my $res = shift; ' . $contents . '}';
    $paramHash->{CHOICE_FUNC} = eval $contents;
}

sub end_choicefunc { return ''; }

sub start_valuefunc {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;

    if ($target ne 'helper') {
        return '';
    }

    my $contents = Apache::lonxml::get_all_text('/valuefunc',
                                                $parser);
    $contents = 'sub { my $res = shift; ' . $contents . '}';
    $paramHash->{VALUE_FUNC} = eval $contents;
}

sub end_valuefunc { return ''; }

sub start_mapurl {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;

    if ($target ne 'helper') {
        return '';
    }

    my $contents = Apache::lonxml::get_all_text('/mapurl',
                                                $parser);
    $paramHash->{EVAL_MAP_URL} = $token->[2]{'evaluate'};
    $paramHash->{MAP_URL} = $contents;
}

sub end_mapurl { return ''; }


sub start_option {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
    if (!defined($paramHash->{OPTION_TEXTS})) {
	$paramHash->{OPTION_TEXTS} = [ ];
	$paramHash->{OPTION_VARS}  = [ ];

    }
    # OPTION_TEXTS is a list of the text attribute
    #               values used to create column headings.
    # OPTION_VARS is a list of the variable names, used to create the checkbox
    #             inputs.
    #  We're ok with empty elements. as place holders
    # Although the 'variable' element should really exist.
    #

    my $option_texts  = $paramHash->{OPTION_TEXTS};
    my $option_vars   = $paramHash->{OPTION_VARS};
    push(@$option_texts,  $token->[2]{'text'});
    push(@$option_vars,   $token->[2]{'variable'});

    #  Need to create and declare the option variables as well to make them
    # persistent.
    #
    my $varname = $token->[2]{'variable'};
    $helper->declareVar($varname);


    return '';
}

sub end_option {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
    return '';
}

# A note, in case I don't get to this before I leave.
# If someone complains about the "Back" button returning them
# to the previous folder state, instead of returning them to
# the previous helper state, the *correct* answer is for the helper
# to keep track of how many times the user has manipulated the folders,
# and feed that to the history.go() call in the helper rendering routines.
# If done correctly, the helper itself can keep track of how many times
# it renders the same states, so it doesn't go in just this state, and
# you can lean on the browser back button to make sure it all chains
# correctly.
# Right now, though, I'm just forcing all folders open.

sub render {
    my $self = shift;
    my $result = "";
    my $var = $self->{'variable'};
    my $curVal = $helper->{VARS}->{$var};

    my $buttons = '';

    if ($self->{'multichoice'}) {
        $result = <<SCRIPT;
<script type="text/javascript">
// <!--
    function checkall(value, checkName) {
	for (i=0; i<document.forms.helpform.elements.length; i++) {
            ele = document.forms.helpform.elements[i];
            if (ele.name == checkName + '_forminput') {
                document.forms.helpform.elements[i].checked=value;
            }
        }
    }
// -->
</script>
SCRIPT
        my %lt=&Apache::lonlocal::texthash(
			'sar'  => "Select All Resources",
		        'uar'  => "Unselect All Resources");

        $buttons = <<BUTTONS;
<br /> &nbsp;
<input type="button" onclick="checkall(true, '$var')" value="$lt{'sar'}" />
<input type="button" onclick="checkall(false, '$var')" value="$lt{'uar'}" />
<br /> &nbsp;
BUTTONS
    }

    if (defined $self->{ERROR_MSG}) {
        $result .= '<br /><font color="#FF0000">' . $self->{ERROR_MSG} . '</font><br /><br />';
    }

    $result .= $buttons;

    my $filterFunc     = $self->{FILTER_FUNC};
    my $choiceFunc     = $self->{CHOICE_FUNC};
    my $valueFunc      = $self->{VALUE_FUNC};
    my $multichoice    = $self->{'multichoice'};
    my $option_vars    = $self->{OPTION_VARS};
    my $option_texts   = $self->{OPTION_TEXTS};
    my $addparts       = $self->{'addparts'};
    my $headings_done  = 0;

    # Evaluate the map url as needed
    my $mapUrl;
    if ($self->{EVAL_MAP_URL}) {
	my $mapUrlFunc = eval('sub { my $helper = shift; my $state = shift; ' . 
	    $self->{MAP_URL} . '}');
	$mapUrl = &$mapUrlFunc($helper, $self);
    } else {
	$mapUrl = $self->{MAP_URL};
    }

    my %defaultSymbs;
    if (defined($self->{DEFAULT_VALUE})) {
        my $valueFunc = eval($self->{DEFAULT_VALUE});
        die 'Error in default value code for variable ' . 
            $self->{'variable'} . ', Perl said: ' . $@ if $@;
        my @defaultSymbs = &$valueFunc($helper, $self);
	if (!$multichoice && @defaultSymbs) { # only allowed 1
	    @defaultSymbs = ($defaultSymbs[0]);
	}
	%defaultSymbs = map { if ($_) {($_,1) } } @defaultSymbs;
	delete($defaultSymbs{''});
    }

    # Create the composite function that renders the column on the nav map
    # have to admit any language that lets me do this can't be all bad
    #  - Jeremy (Pythonista) ;-)
    my $checked = 0;
    my $renderColFunc = sub {
        my ($resource, $part, $params) = @_;
	my $result = "";

	if(!$headings_done) {
	    if ($option_texts) {
		foreach my $text (@$option_texts) {
		    $result .= "<th>$text</th>";
		}
	    }
	    $result .= "<th>Select</th>";
	    $result .= "</tr><tr>"; # Close off the extra row and start a new one.
	    $headings_done = 1;
	}

        my $inputType;
        if ($multichoice) { $inputType = 'checkbox'; }
        else {$inputType = 'radio'; }

        if (!&$choiceFunc($resource)) {
	    $result .= '<td>&nbsp;</td>';
            return $result;
        } else {
	    my $col = "";
	    my $raw_name = &$valueFunc($resource);
	    my $resource_name =   
                   HTML::Entities::encode($raw_name,"<>&\"'");
	    if($option_vars) {
		foreach my $option_var (@$option_vars) {
		    my $var_value = "\|\|\|" . $helper->{VARS}->{$option_var} . 
			"\|\|\|";
		    my $checked ="";
		    if($var_value =~ /\Q|||$raw_name|||\E/) {
			$checked = "checked='checked'";
		    }
		    $col .= 
                        "<td align='center'><input type='checkbox' name ='$option_var".
			"_forminput' value='".
			$resource_name . "' $checked /> </td>";
		}
	    }

            $col .= "<td align='center'><input type='$inputType' name='${var}_forminput' ";
	    if (%defaultSymbs) {
		my $symb=$resource->symb();
		if (exists($defaultSymbs{$symb})) {
		    $col .= "checked='checked' ";
		    $checked = 1;
		}
	    } else {
		if (!$checked && !$multichoice) {
		    $col .= "checked='checked' ";
		    $checked = 1;
		}
		if ($multichoice) { # all resources start checked; see bug 1174
		    $col .= "checked='checked' ";
		    $checked = 1;
		}
	    }
            $col .= "value='" . $resource_name  . "' /></td>";

            return $result.$col;
        }
    };
    my $renderPartsFunc = sub {
        my ($resource, $part, $params) = @_;
	my $col= "<td>";
	my $id=$resource->{ID};
	my $resource_name =   
	    &HTML::Entities::encode(&$valueFunc($resource),"<>&\"'");
	if ($addparts && (scalar(@{$resource->parts}) > 1)) {
	    $col .= "<select onclick=\"javascript:updateRadio(this.form,'${var}_forminput','$resource_name');updateHidden(this.form,'$id','${var}');\" name='part_${id}_forminput'>\n";
	    $col .= "<option value=\"$part\">All Parts</option>\n";
	    foreach my $part (@{$resource->parts}) {
		$col .= "<option value=\"$part\">Part: $part</option>\n";
	    }
	    $col .= "</select>";
	}
	$col .= "</td>";
    };
    $result.=(<<RADIO);
<script type="text/javascript">
// <!--
    function updateRadio(form,name,value) {
	var radiobutton=form[name];
	for (var i=0; i<radiobutton.length; i++) {
	    if (radiobutton[i].value == value) {
		radiobutton[i].checked = true;
		break;
	    }
	}
    }
    function updateHidden(form,id,name) {
	var select=form['part_'+id+'_forminput'];
	var hidden=form[name+'_part_forminput'];
	var which=select.selectedIndex;
	hidden.value=select.options[which].value;
    }
// -->
</script>
<input type="hidden" name="${var}_part_forminput" />

RADIO
    $env{'form.condition'} = !$self->{'toponly'};
    my $cols = [$renderColFunc];
    if ($self->{'addparts'}) { push(@$cols, $renderPartsFunc); }
    push(@$cols, Apache::lonnavmaps::resource());
    if ($self->{'addstatus'}) {
	push @$cols, (Apache::lonnavmaps::part_status_summary());
	
    }
    $result .= 
        &Apache::lonnavmaps::render( { 'cols' => $cols,
                                       'showParts' => 0,
                                       'filterFunc' => $filterFunc,
                                       'resource_no_folder_link' => 1,
				       'closeAllPages' => $self->{'closeallpages'},
                                       'suppressEmptySequences' => $self->{'suppressEmptySequences'},
                                       'iterator_map' => $mapUrl }
                                       );

    $result .= $buttons;
                                                
    return $result;
}
    
sub postprocess {
    my $self = shift;

    if ($self->{'multichoice'} && !$helper->{VARS}->{$self->{'variable'}}) {
        $self->{ERROR_MSG} = 'You must choose at least one resource to continue.';
        return 0;
    }

    if (defined($self->{NEXTSTATE})) {
        $helper->changeState($self->{NEXTSTATE});
    }

    return 1;
}

1;

package Apache::lonhelper::student;

=pod

=head2 Element: studentX<student, helper element>

Student elements display a choice of students enrolled in the current
course. Currently it is primitive; this is expected to evolve later.

Student elements take the following attributes: 

=over 4

=item * B<variable>: 

Does what it usually does: declare which helper variable to put the
result in.

=item * B<multichoice>: 

If true allows the user to select multiple students. Defaults to false.

=item * B<coursepersonnel>: 

If true adds the course personnel to the top of the student
selection. Defaults to false.

=item * B<activeonly>:

If true, only active students and course personnel will be
shown. Defaults to false.

=item * B<emptyallowed>:

If true, the selection of no users is allowed. Defaults to false.

=back

=cut

no strict;
@ISA = ("Apache::lonhelper::element");
use strict;
use Apache::lonlocal;
use Apache::lonnet;

BEGIN {
    &Apache::lonhelper::register('Apache::lonhelper::student',
                              ('student'));
}

sub new {
    my $ref = Apache::lonhelper::element->new();
    bless($ref);
}

sub start_student {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;

    if ($target ne 'helper') {
        return '';
    }

    $paramHash->{'variable'} = $token->[2]{'variable'};
    $helper->declareVar($paramHash->{'variable'});
    $paramHash->{'multichoice'} = $token->[2]{'multichoice'};
    $paramHash->{'coursepersonnel'} = $token->[2]{'coursepersonnel'};
    $paramHash->{'activeonly'} = $token->[2]{'activeonly'};
    if (defined($token->[2]{'nextstate'})) {
        $paramHash->{NEXTSTATE} = $token->[2]{'nextstate'};
    }
    $paramHash->{'emptyallowed'} = $token->[2]{'emptyallowed'};
    
}    

sub end_student {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;

    if ($target ne 'helper') {
        return '';
    }
    Apache::lonhelper::student->new();
}

sub render {
    my $self = shift;
    my $result = '';
    my $buttons = '';
    my $var = $self->{'variable'};


    if (defined $self->{ERROR_MSG}) {
        $result .= '<font color="#FF0000">' . $self->{ERROR_MSG} . '</font><br /><br />';
    }

    my %defaultUsers;
    if (defined($self->{DEFAULT_VALUE})) {
        my $valueFunc = eval($self->{DEFAULT_VALUE});
        die 'Error in default value code for variable ' . 
            $self->{'variable'} . ', Perl said: ' . $@ if $@;
        my @defaultUsers = &$valueFunc($helper, $self);
	if (!$self->{'multichoice'} && @defaultUsers) { # only allowed 1
	    @defaultUsers = ($defaultUsers[0]);
	}
	%defaultUsers = map { if ($_) {($_,1) } } @defaultUsers;
	delete($defaultUsers{''});
    }


    my ($course_personnel, 
	$current_members, 
	$expired_members, 
	$future_members) = 
	    &Apache::lonselstudent::get_people_in_class($env{'request.course.sec'});



    # Load up the non-students, if necessary

    if ($self->{'coursepersonnel'}) {
	unshift @$current_members, (@$course_personnel);
    }


    #   Current personel

    $result .= '<h4>'.&mt('Select Currently Enrolled Students and Active Course Personnel').'</h4>';
    $result .= &Apache::lonselstudent::render_student_list( $current_members,
							    "helpform",
							    "current", 
							    \%defaultUsers,
							    $self->{'multichoice'},
							    $self->{'variable'},
							    1);


    # If activeonly is not set then we can also give the expired students:
    #
    if (!$self->{'activeonly'} && ((scalar(@$future_members)) > 0)) {

	# And future.

	$result .= '<h4>'.&mt('Select Future Enrolled Students and Future Course Personnel').'</h4>';
       
	$result .= &Apache::lonselstudent::render_student_list( $future_members,
								"helpform",
								"future",
								\%defaultUsers,
								$self->{'multichoice'},
								$self->{'variable'},
								0);
    }
    if (!$self->{'activeonly'} && ((scalar(@$expired_members)) > 0)) {
	# Past 

	$result .= '<h4>'.&mt('Select Previously Enrolled Students and Inactive Course Personnel').'</h4>';
	$result .= &Apache::lonselstudent::render_student_list($expired_members,
							       "helpform",
							       "past",
							       \%defaultUsers,
							       $self->{'multichoice'},
							       $self->{'variable'},
							       0);
    }



    return $result;
}

sub postprocess {
    my $self = shift;

    my $result = $env{'form.' . $self->{'variable'} . '_forminput'};
    if (!$result && !$self->{'emptyallowed'}) {
	if ($self->{'coursepersonnel'}) {
	    $self->{ERROR_MSG} = 
		&mt('You must choose at least one user to continue.');
	} else {
	    $self->{ERROR_MSG} = 
		&mt('You must choose at least one student to continue.');
	}
        return 0;
    }

    if (defined($self->{NEXTSTATE})) {
        $helper->changeState($self->{NEXTSTATE});
    }

    return 1;
}

1;

package Apache::lonhelper::files;

=pod

=head2 Element: filesX<files, helper element>

files allows the users to choose files from a given directory on the
server. It is always multichoice and stores the result as a triple-pipe
delimited entry in the helper variables. 

Since it is extremely unlikely that you can actually code a constant
representing the directory you wish to allow the user to search, <files>
takes a subroutine that returns the name of the directory you wish to
have the user browse.

files accepts the attribute "variable" to control where the files chosen
are put. It accepts the attribute "multichoice" as the other attribute,
defaulting to false, which if true will allow the user to select more
then one choice. 

<files> accepts three subtags: 

=over 4

=item * B<nextstate>: works as it does with the other tags. 

=item * B<filechoice>: When the contents of this tag are surrounded by
    "sub {" and "}", will return a string representing what directory
    on the server to allow the user to choose files from. 

=item * B<filefilter>: Should contain Perl code that when surrounded
    by "sub { my $filename = shift; " and "}", returns a true value if
    the user can pick that file, or false otherwise. The filename
    passed to the function will be just the name of the file, with no
    path info. By default, a filter function will be used that will
    mask out old versions of files. This function is available as
    Apache::lonhelper::files::not_old_version if you want to use it to
    composite your own filters.

=back

B<General security note>: You should ensure the user can not somehow 
pass something into your code that would allow them to look places 
they should not be able to see, like the C</etc/> directory. However,
the security impact would be minimal, since it would only expose
the existence of files, there should be no way to parlay that into
viewing the files. 

=cut

no strict;
@ISA = ("Apache::lonhelper::element");
use strict;
use Apache::lonlocal;
use Apache::lonnet;
use Apache::lonpubdir; # for getTitleString

BEGIN {
    &Apache::lonhelper::register('Apache::lonhelper::files',
                                 ('files', 'filechoice', 'filefilter'));
}

sub not_old_version {
    my $file = shift;
    
    # Given a file name, return false if it is an "old version" of a
    # file, or true if it is not.

    if ($file =~ /^.*\.[0-9]+\.[A-Za-z]+(\.meta)?$/) {
	return 0;
    }
    return 1;
}

sub new {
    my $ref = Apache::lonhelper::element->new();
    bless($ref);
}

sub start_files {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;

    if ($target ne 'helper') {
        return '';
    }
    $paramHash->{'variable'} = $token->[2]{'variable'};
    $helper->declareVar($paramHash->{'variable'});
    $paramHash->{'multichoice'} = $token->[2]{'multichoice'};
}    

sub end_files {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;

    if ($target ne 'helper') {
        return '';
    }
    if (!defined($paramHash->{FILTER_FUNC})) {
        $paramHash->{FILTER_FUNC} = sub { return 1; };
    }
    Apache::lonhelper::files->new();
}    

sub start_filechoice {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;

    if ($target ne 'helper') {
        return '';
    }
    $paramHash->{'filechoice'} = Apache::lonxml::get_all_text('/filechoice',
                                                              $parser);
}

sub end_filechoice { return ''; }

sub start_filefilter {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;

    if ($target ne 'helper') {
        return '';
    }

    my $contents = Apache::lonxml::get_all_text('/filefilter',
                                                $parser);
    $contents = 'sub { my $filename = shift; ' . $contents . '}';
    $paramHash->{FILTER_FUNC} = eval $contents;
}

sub end_filefilter { return ''; }

{ 
    # used to generate unique id attributes for <input> tags. 
    # internal use only.
    my $id=0;
    sub new_id { return $id++;}
}

sub render {
    my $self = shift;
    my $result = '';
    my $var = $self->{'variable'};
    
    my $subdirFunc = eval('sub {' . $self->{'filechoice'} . '}');
    die 'Error in resource filter code for variable ' . 
        {'variable'} . ', Perl said:' . $@ if $@;

    my $subdir = &$subdirFunc();

    my $filterFunc = $self->{FILTER_FUNC};
    if (!defined($filterFunc)) {
	$filterFunc = &not_old_version;
    }
    my $buttons = '';
    my $type = 'radio';
    if ($self->{'multichoice'}) {
        $type = 'checkbox';
    }

    if ($self->{'multichoice'}) {
        $result = <<SCRIPT;
<script type="text/javascript">
// <!--
    function checkall(value, checkName) {
	for (i=0; i<document.forms.helpform.elements.length; i++) {
            ele = document.forms.helpform.elements[i];
            if (ele.name == checkName + '_forminput') {
                document.forms.helpform.elements[i].checked=value;
            }
        }
    }

    function checkallclass(value, className) {
        for (i=0; i<document.forms.helpform.elements.length; i++) {
            ele = document.forms.helpform.elements[i];
            if (ele.type == "$type" && ele.onclick) {
                document.forms.helpform.elements[i].checked=value;
            }
        }
    }
// -->
</script>
SCRIPT
       my %lt=&Apache::lonlocal::texthash(
			'saf'  => "Select All Files",
		        'uaf'  => "Unselect All Files");
       $buttons = <<BUTTONS;
<br /> &nbsp;
<input type="button" onclick="checkall(true, '$var')" value="$lt{'saf'}" />
<input type="button" onclick="checkall(false, '$var')" value="$lt{'uaf'}" />
BUTTONS

       %lt=&Apache::lonlocal::texthash(
			'sap'  => "Select All Published",
		        'uap'  => "Unselect All Published");
        if ($helper->{VARS}->{'construction'}) {
       $buttons .= <<BUTTONS;
<input type="button" onclick="checkallclass(true, 'Published')" value="$lt{'sap'}" />
<input type="button" onclick="checkallclass(false, 'Published')" value="$lt{'uap'}" />
<br /> &nbsp;
BUTTONS
       }
    }

    # Get the list of files in this directory.
    my @fileList;

    # If the subdirectory is in local CSTR space
    my $metadir;
    if ($subdir =~ m|/home/([^/]+)/public_html/(.*)|) {
	my ($user,$domain)= 
	    &Apache::loncacc::constructaccess($subdir,
				     $Apache::lonnet::perlvar{'lonDefDomain'});
	$metadir='/res/'.$domain.'/'.$user.'/'.$2;
        @fileList = &Apache::lonnet::dirlist($subdir, $domain, $user, '');
    } elsif ($subdir =~ m|^~([^/]+)/(.*)$|) {
	$subdir='/home/'.$1.'/public_html/'.$2;
	my ($user,$domain)= 
	    &Apache::loncacc::constructaccess($subdir,
				     $Apache::lonnet::perlvar{'lonDefDomain'});
	$metadir='/res/'.$domain.'/'.$user.'/'.$2;
        @fileList = &Apache::lonnet::dirlist($subdir, $domain, $user, '');
    } else {
        # local library server resource space
        @fileList = &Apache::lonnet::dirlist($subdir, $env{'user.domain'}, $env{'user.name'}, '');
    }

    # Sort the fileList into order
    @fileList = sort {lc($a) cmp lc($b)} @fileList;

    $result .= $buttons;

    if (defined $self->{ERROR_MSG}) {
        $result .= '<br /><font color="#FF0000">' . $self->{ERROR_MSG} . '</font><br /><br />';
    }

    $result .= '<table border="0" cellpadding="2" cellspacing="0">';

    # Keeps track if there are no choices, prints appropriate error
    # if there are none. 
    my $choices = 0;
    # Print each legitimate file choice.
    for my $file (@fileList) {
        $file = (split(/&/, $file))[0];
        if ($file eq '.' || $file eq '..') {
            next;
        }
        my $fileName = $subdir .'/'. $file;
        if (&$filterFunc($file)) {
	    my $status;
	    my $color;
	    if ($helper->{VARS}->{'construction'}) {
		($status, $color) = @{fileState($subdir, $file)};
	    } else {
		$status = '';
		$color = '';
	    }

            # Get the title
            my $title = Apache::lonpubdir::getTitleString(($metadir?$metadir:$subdir) .'/'. $file);

            # Netscape 4 is stupid and there's nowhere to put the
            # information on the input tag that the file is Published,
            # Unpublished, etc. In *real* browsers we can just say
            # "class='Published'" and check the className attribute of
            # the input tag, but Netscape 4 is too stupid to understand
            # that attribute, and un-comprehended attributes are not
            # reflected into the object model. So instead, what I do 
            # is either have or don't have an "onclick" handler that 
            # does nothing, give Published files the onclick handler, and
            # have the checker scripts check for that. Stupid and clumsy,
            # and only gives us binary "yes/no" information (at least I
            # couldn't figure out how to reach into the event handler's
            # actual code to retreive a value), but it works well enough
            # here.
        
            my $onclick = '';
            if ($status eq 'Published' && $helper->{VARS}->{'construction'}) {
                $onclick = 'onclick="a=1" ';
            }
            my $id = &new_id();
            $result .= '<tr><td align="right"' . " bgcolor='$color'>" .
                "<input $onclick type='$type' name='" . $var
            . "_forminput' ".qq{id="$id"}." value='" . HTML::Entities::encode($fileName,"<>&\"'").
                "'";
            if (!$self->{'multichoice'} && $choices == 0) {
                $result .= ' checked="checked"';
            }
            $result .= "/></td><td bgcolor='$color'>".
                qq{<label for="$id">}. $file . "</label></td>" .
                "<td bgcolor='$color'>$title</td>" .
                "<td bgcolor='$color'>$status</td>" . "</tr>\n";
            $choices++;
        }
    }

    $result .= "</table>\n";

    if (!$choices) {
        $result .= '<font color="#FF0000">There are no files available to select in this directory ('.$subdir.'). Please go back and select another option.</font><br /><br />';
    }

    $result .= $buttons;

    return $result;
}

# Determine the state of the file: Published, unpublished, modified.
# Return the color it should be in and a label as a two-element array
# reference.
# Logic lifted from lonpubdir.pm, even though I don't know that it's still
# the most right thing to do.

sub fileState {
    my $constructionSpaceDir = shift;
    my $file = shift;
    
    my ($uname,$udom)=($env{'user.name'},$env{'user.domain'});
    if ($env{'request.role'}=~/^ca\./) {
	(undef,$udom,$uname)=split(/\//,$env{'request.role'});
    }
    my $docroot = $Apache::lonnet::perlvar{'lonDocRoot'};
    my $subdirpart = $constructionSpaceDir;
    $subdirpart =~ s/^\/home\/$uname\/public_html//;
    my $resdir = $docroot . '/res/' . $udom . '/' . $uname .
        $subdirpart;

    my @constructionSpaceFileStat = stat($constructionSpaceDir . '/' . $file);
    my @resourceSpaceFileStat = stat($resdir . '/' . $file);
    if (!@resourceSpaceFileStat) {
        return ['Unpublished', '#FFCCCC'];
    }

    my $constructionSpaceFileModified = $constructionSpaceFileStat[9];
    my $resourceSpaceFileModified = $resourceSpaceFileStat[9];
    
    if ($constructionSpaceFileModified > $resourceSpaceFileModified) {
        return ['Modified', '#FFFFCC'];
    }
    return ['Published', '#CCFFCC'];
}

sub postprocess {
    my $self = shift;
    my $result = $env{'form.' . $self->{'variable'} . '_forminput'};
    if (!$result) {
        $self->{ERROR_MSG} = 'You must choose at least one file '.
            'to continue.';
        return 0;
    }

    if (defined($self->{NEXTSTATE})) {
        $helper->changeState($self->{NEXTSTATE});
    }

    return 1;
}

1;

package Apache::lonhelper::section;

=pod

=head2 Element: sectionX<section, helper element>

<section> allows the user to choose one or more sections from the current
course.

It takes the standard attributes "variable", "multichoice",
"allowempty" and "nextstate", meaning what they do for most other
elements.

also takes a boolean 'onlysections' whcih will restrict this to only
have sections and not include groups

=cut

no strict;
@ISA = ("Apache::lonhelper::choices");
use strict;

BEGIN {
    &Apache::lonhelper::register('Apache::lonhelper::section',
                                 ('section'));
}

sub new {
    my $ref = Apache::lonhelper::choices->new();
    bless($ref);
}

sub start_section {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;

    if ($target ne 'helper') {
        return '';
    }

    $paramHash->{CHOICES} = [];

    $paramHash->{'variable'} = $token->[2]{'variable'};
    $helper->declareVar($paramHash->{'variable'});
    $paramHash->{'multichoice'} = $token->[2]{'multichoice'};
    $paramHash->{'allowempty'} = $token->[2]{'allowempty'};
    if (defined($token->[2]{'nextstate'})) {
        $paramHash->{NEXTSTATE} = $token->[2]{'nextstate'};
    }

    # Populate the CHOICES element
    my %choices;

    my $section = Apache::loncoursedata::CL_SECTION();
    my $classlist = Apache::loncoursedata::get_classlist();
    foreach my $user (keys(%$classlist)) {
        my $section_name = $classlist->{$user}[$section];
        if (!$section_name) {
            $choices{"No section assigned"} = "";
        } else {
            $choices{$section_name} = $section_name;
        }
    } 
   
    if (exists($choices{"No section assigned"})) {
	push(@{$paramHash->{CHOICES}}, 
	     ['No section assigned','No section assigned']);
	delete($choices{"No section assigned"});
    }
    for my $section_name (sort {lc($a) cmp lc($b) } (keys(%choices))) {
	push @{$paramHash->{CHOICES}}, [$section_name, $section_name];
    }
    return if ($token->[2]{'onlysections'});

    # add in groups to the end of the list
    my %curr_groups = &Apache::longroup::coursegroups();
    foreach my $group_name (sort(keys(%curr_groups))) {
	push(@{$paramHash->{CHOICES}}, [$group_name, $group_name]);
    }
}    

sub end_section {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;

    if ($target ne 'helper') {
        return '';
    }
    Apache::lonhelper::section->new();
}    
1;

package Apache::lonhelper::group;

=pod
 
=head2 Element: groupX<group, helper element>
 
<group> allows the user to choose one or more groups from the current course.

It takes the standard attributes "variable", "multichoice",
 "allowempty" and "nextstate", meaning what they do for most other
 elements.

=cut

no strict;
@ISA = ("Apache::lonhelper::choices");
use strict;

BEGIN {
    &Apache::lonhelper::register('Apache::lonhelper::group',
                                 ('group'));
}

sub new {
    my $ref = Apache::lonhelper::choices->new();
    bless($ref);
}
 
sub start_group {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
 
    if ($target ne 'helper') {
        return '';
    }

    $paramHash->{CHOICES} = [];

    $paramHash->{'variable'} = $token->[2]{'variable'};
    $helper->declareVar($paramHash->{'variable'});
    $paramHash->{'multichoice'} = $token->[2]{'multichoice'};
    $paramHash->{'allowempty'} = $token->[2]{'allowempty'};
    if (defined($token->[2]{'nextstate'})) {
        $paramHash->{NEXTSTATE} = $token->[2]{'nextstate'};
    }

    # Populate the CHOICES element
    my %choices;

    my %curr_groups = &Apache::longroup::coursegroups();
    foreach my $group_name (sort {lc($a) cmp lc($b)} (keys(%curr_groups))) {
	push(@{$paramHash->{CHOICES}}, [$group_name, $group_name]);
    }
}

sub end_group {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;

    if ($target ne 'helper') {
        return '';
    }
    Apache::lonhelper::group->new();
}
1;

package Apache::lonhelper::string;

=pod

=head2 Element: stringX<string, helper element>

string elements provide a string entry field for the user. string elements
take the usual 'variable' and 'nextstate' parameters. string elements
also pass through 'maxlength' and 'size' attributes to the input tag.

string honors the defaultvalue tag, if given.

string honors the validation function, if given.

=cut

no strict;
@ISA = ("Apache::lonhelper::element");
use strict;
use Apache::lonlocal;

BEGIN {
    &Apache::lonhelper::register('Apache::lonhelper::string',
                              ('string'));
}

sub new {
    my $ref = Apache::lonhelper::element->new();
    bless($ref);
}

# CONSTRUCTION: Construct the message element from the XML
sub start_string {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;

    if ($target ne 'helper') {
        return '';
    }

    $paramHash->{'variable'} = $token->[2]{'variable'};
    $helper->declareVar($paramHash->{'variable'});
    $paramHash->{'nextstate'} = $token->[2]{'nextstate'};
    $paramHash->{'maxlength'} = $token->[2]{'maxlength'};
    $paramHash->{'size'} = $token->[2]{'size'};

    return '';
}

sub end_string {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;

    if ($target ne 'helper') {
        return '';
    }
    Apache::lonhelper::string->new();
    return '';
}

sub render {
    my $self = shift;
    my $result = '';

    if (defined $self->{ERROR_MSG}) {
        $result .= '<p><font color="#FF0000">' . $self->{ERROR_MSG} . '</font></p>';
    }

    $result .= '<input type="string" name="' . $self->{'variable'} . '_forminput"';

    if (defined($self->{'size'})) {
        $result .= ' size="' . $self->{'size'} . '"';
    }
    if (defined($self->{'maxlength'})) {
        $result .= ' maxlength="' . $self->{'maxlength'} . '"';
    }

    if (defined($self->{DEFAULT_VALUE})) {
        my $valueFunc = eval($self->{DEFAULT_VALUE});
        die 'Error in default value code for variable ' . 
            $self->{'variable'} . ', Perl said: ' . $@ if $@;
        $result .= ' value="' . &$valueFunc($helper, $self) . '"';
    }

    $result .= ' />';

    return $result;
}

# If a NEXTSTATE was given, switch to it
sub postprocess {
    my $self = shift;

    if (defined($self->{VALIDATOR})) {
	my $validator = eval($self->{VALIDATOR});
	die 'Died during evaluation of validator code; Perl said: ' . $@ if $@;
	my $invalid = &$validator($helper, $state, $self, $self->getValue());
	if ($invalid) {
	    $self->{ERROR_MSG} = $invalid;
	    return 0;
	}
    }

    if (defined($self->{'nextstate'})) {
        $helper->changeState($self->{'nextstate'});
    }

    return 1;
}

1;

package Apache::lonhelper::general;

=pod

=head2 General-purpose tag: <exec>X<exec, helper tag>

The contents of the exec tag are executed as Perl code, B<not> inside a 
safe space, so the full range of $env and such is available. The code
will be executed as a subroutine wrapped with the following code:

"sub { my $helper = shift; my $state = shift;" and

"}"

The return value is ignored.

$helper is the helper object. Feel free to add methods to the helper
object to support whatever manipulation you may need to do (for instance,
overriding the form location if the state is the final state; see 
parameter.helper for an example).

$state is the $paramHash that has currently been generated and may
be manipulated by the code in exec. Note that the $state is not yet
an actual state B<object>, it is just a hash, so do not expect to
be able to call methods on it.

=cut

use Apache::lonlocal;
use Apache::lonnet;

BEGIN {
    &Apache::lonhelper::register('Apache::lonhelper::general',
                                 'exec', 'condition', 'clause',
                                 'eval');
}

sub start_exec {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;

    if ($target ne 'helper') {
        return '';
    }
    
    my $code = &Apache::lonxml::get_all_text('/exec', $parser);
    
    $code = eval ('sub { my $helper = shift; my $state = shift; ' .
        $code . "}");
    die 'Error in <exec>, Perl said: '. $@ if $@;
    &$code($helper, $paramHash);
}

sub end_exec { return ''; }

=pod

=head2 General-purpose tag: <condition>

The <condition> tag allows you to mask out parts of the helper code
depending on some programatically determined condition. The condition
tag contains a tag <clause> which contains perl code that when wrapped
with "sub { my $helper = shift; my $state = shift; " and "}", returns
a true value if the XML in the condition should be evaluated as a normal
part of the helper, or false if it should be completely discarded.

The <clause> tag must be the first sub-tag of the <condition> tag or
it will not work as expected.

=cut

# The condition tag just functions as a marker, it doesn't have
# to "do" anything. Technically it doesn't even have to be registered
# with the lonxml code, but I leave this here to be explicit about it.
sub start_condition { return ''; }
sub end_condition { return ''; }

sub start_clause {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;

    if ($target ne 'helper') {
        return '';
    }
    
    my $clause = Apache::lonxml::get_all_text('/clause', $parser);
    $clause = eval('sub { my $helper = shift; my $state = shift; '
        . $clause . '}');
    die 'Error in clause of condition, Perl said: ' . $@ if $@;
    if (!&$clause($helper, $paramHash)) {
        # Discard all text until the /condition.
	my $end_tag = $paramHash->{SKIPTAG} || '/condition';
        &Apache::lonxml::get_all_text($end_tag, $parser);
    }
}

sub end_clause { return ''; }

=pod

=head2 General-purpose tag: <eval>X<eval, helper tag>

The <eval> tag will be evaluated as a subroutine call passed in the
current helper object and state hash as described in <condition> above,
but is expected to return a string to be printed directly to the
screen. This is useful for dynamically generating messages. 

=cut

# This is basically a type of message.
# Programmatically setting $paramHash->{NEXTSTATE} would work, though
# it's probably bad form.

sub start_eval {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;

    if ($target ne 'helper') {
        return '';
    }
    
    my $program = Apache::lonxml::get_all_text('/eval', $parser);
    $program = eval('sub { my $helper = shift; my $state = shift; '
        . $program . '}');
    die 'Error in eval code, Perl said: ' . $@ if $@;
    $paramHash->{MESSAGE_TEXT} = &$program($helper, $paramHash);
}

sub end_eval { 
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;

    if ($target ne 'helper') {
        return '';
    }

    Apache::lonhelper::message->new();
}

1;

package Apache::lonhelper::final;

=pod

=head2 Element: finalX<final, helper tag>

<final> is a special element that works with helpers that use the <finalcode>
tagX<finalcode, helper tag>. It goes through all the states and elements, executing the <finalcode>
snippets and collecting the results. Finally, it takes the user out of the
helper, going to a provided page.

If the parameter "restartCourse" is true, this will override the buttons and
will make a "Finish Helper" button that will re-initialize the course for them,
which is useful for the Course Initialization helper so the users never see
the old values taking effect.

If the parameter "restartCourse" is not true a 'Finish' Button will be
presented that takes the user back to whatever was defined as <exitpage>

=cut

no strict;
@ISA = ("Apache::lonhelper::element");
use strict;
use Apache::lonlocal;
use Apache::lonnet;
BEGIN {
    &Apache::lonhelper::register('Apache::lonhelper::final',
                                 ('final', 'exitpage'));
}

sub new {
    my $ref = Apache::lonhelper::element->new();
    bless($ref);
}

sub start_final { 
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;

    if ($target ne 'helper') {
        return '';
    }

    $paramHash->{'restartCourse'} = $token->[2]{'restartCourse'};

    return ''; 
}

sub end_final {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;

    if ($target ne 'helper') {
        return '';
    }

    Apache::lonhelper::final->new();
   
    return '';
}

sub start_exitpage {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;

    if ($target ne 'helper') {
        return '';
    }

    $paramHash->{EXIT_PAGE} = &Apache::lonxml::get_all_text('/exitpage',
                                                            $parser);

    return '';
}

sub end_exitpage { return ''; }

sub render {
    my $self = shift;

    my @results;

    # Collect all the results
    for my $stateName (keys %{$helper->{STATES}}) {
        my $state = $helper->{STATES}->{$stateName};
        
        for my $element (@{$state->{ELEMENTS}}) {
            if (defined($element->{FINAL_CODE})) {
                # Compile the code.
                my $code = 'sub { my $helper = shift; my $element = shift; ' 
                    . $element->{FINAL_CODE} . '}';
                $code = eval($code);
                die 'Error while executing final code for element with var ' .
                    $element->{'variable'} . ', Perl said: ' . $@ if $@;

                my $result = &$code($helper, $element);
                if ($result) {
                    push @results, $result;
                }
            }
        }
    }

    my $result;

    if (scalar(@results) != 0) {
	$result .= "<ul>\n";
	for my $re (@results) {
	    $result .= '    <li>' . $re . "</li>\n";
	}
	
	if (!@results) {
	    $result .= '    <li>' . 
		&mt('No changes were made to current settings.') . '</li>';
	}
	
	$result .= '</ul>';
    }

    my $actionURL = $self->{EXIT_PAGE};
    my $targetURL = '';
    my $finish=&mt('Finish');
    if ($self->{'restartCourse'}) {
	$actionURL = '/adm/roles';
	$targetURL = '/adm/menu';
	if ($env{'course.'.$env{'request.course.id'}.'.url'}=~/^uploaded/) {
	    $targetURL = '/adm/coursedocs';
	} else {
	    $targetURL = '/adm/navmaps';
	}
	if ($env{'course.'.$env{'request.course.id'}.'.clonedfrom'}) {
	    $targetURL = '/adm/parmset?overview=1';
	}
	my $finish=&mt('Finish Course Initialization');
    }
    my $previous = HTML::Entities::encode(&mt("<- Previous"), '<>&"');
    my $next = HTML::Entities::encode(&mt("Next ->"), '<>&"');
    my $target = " target='loncapaclient'";
    if (($env{'browser.interface'} eq 'textual') ||
        ($env{'environment.remote'} eq 'off')) {  $target='';  }
    $result .= "<center>\n" .
	"<form action='".$actionURL."' method='post' $target>\n" .
	"<input type='button' onclick='history.go(-1)' value='$previous' />" .
	"<input type='hidden' name='orgurl' value='$targetURL' />" .
	"<input type='hidden' name='selectrole' value='1' />\n" .
	"<input type='hidden' name='" . $env{'request.role'} . 
	"' value='1' />\n<input type='submit' value='" . $finish . "' />\n" .
	"</form></center>";

    return $result;
}

sub overrideForm {
    return 1;
}

1;

package Apache::lonhelper::parmwizfinal;

# This is the final state for the parm helper. It is not generally useful,
# so it is not perldoc'ed. It does its own processing.
# It is represented with <parmwizfinal />, and
# should later be moved to lonparmset.pm .

no strict;
@ISA = ('Apache::lonhelper::element');
use strict;
use Apache::lonlocal;
use Apache::lonnet;

BEGIN {
    &Apache::lonhelper::register('Apache::lonhelper::parmwizfinal',
                                 ('parmwizfinal'));
}

use Time::localtime;

sub new {
    my $ref = Apache::lonhelper::choices->new();
    bless ($ref);
}

sub start_parmwizfinal { return ''; }

sub end_parmwizfinal {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;

    if ($target ne 'helper') {
        return '';
    }
    Apache::lonhelper::parmwizfinal->new();
}

# Renders a form that, when submitted, will form the input to lonparmset.pm
sub render {
    my $self = shift;
    my $vars = $helper->{VARS};

    # FIXME: Unify my designators with the standard ones
    my %dateTypeHash = ('open_date' => "opening date",
                        'due_date' => "due date",
                        'answer_date' => "answer date",
			'tries' => 'number of tries',
			'weight' => 'problem weight'
			);
    my %parmTypeHash = ('open_date' => "0_opendate",
                        'due_date' => "0_duedate",
                        'answer_date' => "0_answerdate",
			'tries' => '0_maxtries',
			'weight' => '0_weight' );
    my %realParmName = ('open_date' => "opendate",
                        'due_date' => "duedate",
                        'answer_date' => "answerdate",
			'tries' => 'maxtries',
			'weight' => 'weight' );
    
    my $affectedResourceId = "";
    my $parm_name = $parmTypeHash{$vars->{ACTION_TYPE}};
    my $level = "";
    my $resourceString;
    my $symb;
    my $paramlevel;
    
    # Print the granularity, depending on the action
    if ($vars->{GRANULARITY} eq 'whole_course') {
        $resourceString .= '<li>'.&mt('for <b>all resources in the course</b>').'</li>';
	if ($vars->{TARGETS} eq 'course') {
	    $level = 14; # general course, see lonparmset.pm perldoc
	} elsif ($vars->{TARGETS} eq 'section') {
	    $level = 9;
	} elsif ($vars->{TARGETS} eq 'group') {
	    $level = 6;
	} else {
	    $level = 3;
	}
        $affectedResourceId = "0.0";
        $symb = 'a';
        $paramlevel = 'general';
    } elsif ($vars->{GRANULARITY} eq 'map') {
        my $navmap = Apache::lonnavmaps::navmap->new();
        my $res = $navmap->getByMapPc($vars->{RESOURCE_ID});
        my $title = $res->compTitle();
        $symb = $res->symb();
        $resourceString .= '<li>'.&mt('for the map named [_1]',"<b>$title</b>").'</li>';
	if ($vars->{TARGETS} eq 'course') {
	    $level = 13; # general course, see lonparmset.pm perldoc
	} elsif ($vars->{TARGETS} eq 'section') {
	    $level = 8;
	} elsif ($vars->{TARGETS} eq 'group') {
	    $level = 5;
	} else {
	    $level = 2;
	}
        $affectedResourceId = $vars->{RESOURCE_ID};
        $paramlevel = 'map';
    } else {
        my $navmap = Apache::lonnavmaps::navmap->new();
        my $res = $navmap->getById($vars->{RESOURCE_ID});
        my $part = $vars->{RESOURCE_ID_part};
	if ($part ne 'All Parts' && $part) { $parm_name=~s/^0/$part/; } else { $part=&mt('All Parts'); }
        $symb = $res->symb();
        my $title = $res->compTitle();
        $resourceString .= '<li>'.&mt('for the resource named [_1] part [_2]',"<b>$title</b>","<b>$part</b>").'</li>';
	if ($vars->{TARGETS} eq 'course') {
	    $level = 10; # general course, see lonparmset.pm perldoc
	} elsif ($vars->{TARGETS} eq 'section') {
	    $level = 7;
	} elsif ($vars->{TARGETS} eq 'group') {
	    $level = 4;
	} else {
	    $level = 1;
	}
        $affectedResourceId = $vars->{RESOURCE_ID};
        $paramlevel = 'full';
    }

    my $result = "<form name='helpform' method='POST' action='/adm/parmset#$affectedResourceId&$parm_name&$level'>\n";
    $result .= "<input type='hidden' name='action' value='settable' />\n";
    $result .= "<input type='hidden' name='dis' value='helper' />\n";
    $result .= "<input type='hidden' name='pscat' value='".
	$realParmName{$vars->{ACTION_TYPE}}."' />\n";
    if ($vars->{GRANULARITY} eq 'resource') {
	$result .= "<input type='hidden' name='symb' value='".
	    HTML::Entities::encode($symb,"'<>&\"") . "' />\n";
    } elsif ($vars->{GRANULARITY} eq 'map') {
	$result .= "<input type='hidden' name='pschp' value='".
	    $affectedResourceId."' />\n";
    }
    my $part = $vars->{RESOURCE_ID_part};
    if ($part eq 'All Parts' || !$part) { $part=0; }
    $result .= "<input type='hidden' name='psprt' value='".
	HTML::Entities::encode($part,"'<>&\"") . "' />\n";

    $result .= '<p>'.&mt('Confirm that this information is correct, then click &quot;Finish Helper&quot; to complete setting the parameter.').'<ul>';
    
    # Print the type of manipulation:
    my $extra;
    if ($vars->{ACTION_TYPE} eq 'tries') {
	$extra =  $vars->{TRIES};
    }
    if ($vars->{ACTION_TYPE} eq 'weight') {
	$extra =  $vars->{WEIGHT};
    }
    $result .= "<li>";
    my $what = &mt($dateTypeHash{$vars->{ACTION_TYPE}});
    if ($extra) {
	$result .= &mt('Setting the [_1] to [_2]',"<b>$what</b>",$extra);
    } else {
	$result .= &mt('Setting the [_1]',"<b>$what</b>");
    }
    $result .= "</li>\n";
    if ($vars->{ACTION_TYPE} eq 'due_date' || 
        $vars->{ACTION_TYPE} eq 'answer_date') {
        # for due dates, we default to "date end" type entries
        $result .= "<input type='hidden' name='recent_date_end' " .
            "value='" . $vars->{PARM_DATE} . "' />\n";
        $result .= "<input type='hidden' name='pres_value' " . 
            "value='" . $vars->{PARM_DATE} . "' />\n";
        $result .= "<input type='hidden' name='pres_type' " .
            "value='date_end' />\n";
    } elsif ($vars->{ACTION_TYPE} eq 'open_date') {
        $result .= "<input type='hidden' name='recent_date_start' ".
            "value='" . $vars->{PARM_DATE} . "' />\n";
        $result .= "<input type='hidden' name='pres_value' " .
            "value='" . $vars->{PARM_DATE} . "' />\n";
        $result .= "<input type='hidden' name='pres_type' " .
            "value='date_start' />\n";
    } elsif ($vars->{ACTION_TYPE} eq 'tries') {
	$result .= "<input type='hidden' name='pres_value' " .
	    "value='" . $vars->{TRIES} . "' />\n";
        $result .= "<input type='hidden' name='pres_type' " .
            "value='int_pos' />\n";
    } elsif ($vars->{ACTION_TYPE} eq 'weight') {
	$result .= "<input type='hidden' name='pres_value' " .
	    "value='" . $vars->{WEIGHT} . "' />\n";
    }

    $result .= $resourceString;
    
    # Print targets
    if ($vars->{TARGETS} eq 'course') {
        $result .= '<li>'.&mt('for <b>all students in course</b>').'</li>';
    } elsif ($vars->{TARGETS} eq 'section') {
        my $section = $vars->{SECTION_NAME};
        $result .= '<li>'.&mt('for section [_1]',"<b>$section</b>").'</li>';
	$result .= "<input type='hidden' name='csec' value='" .
            HTML::Entities::encode($section,"'<>&\"") . "' />\n";
    } elsif ($vars->{TARGETS} eq 'group') {
        my $group = $vars->{GROUP_NAME};
        $result .= '<li>'.&mt('for group [_1]',"<b>$group</b>").'</li>';
        $result .= "<input type='hidden' name='cgroup' value='" .
            HTML::Entities::encode($group,"'<>&\"") . "' />\n";
    } else {
        # FIXME: This is probably wasteful! Store the name!
        my $classlist = Apache::loncoursedata::get_classlist();
	my ($uname,$udom)=split(':',$vars->{USER_NAME});
        my $name = $classlist->{$uname.':'.$udom}->[6];
        $result .= '<li>'.&mt('for [_1]',"<b>$name</b>").'</li>';
        $result .= "<input type='hidden' name='uname' value='".
            HTML::Entities::encode($uname,"'<>&\"") . "' />\n";
        $result .= "<input type='hidden' name='udom' value='".
            HTML::Entities::encode($udom,"'<>&\"") . "' />\n";
    }

    # Print value
    if ($vars->{ACTION_TYPE} ne 'tries' && $vars->{ACTION_TYPE} ne 'weight') {
	$result .= '<li>'.&mt('to [_1] ([_2])',"<b>".ctime($vars->{PARM_DATE})."</b>",Apache::lonnavmaps::timeToHumanString($vars->{PARM_DATE}))."</li>\n";
    }
 
    # print pres_marker
    $result .= "\n<input type='hidden' name='pres_marker'" .
        " value='$affectedResourceId&$parm_name&$level' />\n";
    
    # Make the table appear
    $result .= "\n<input type='hidden' value='true' name='prevvisit' />";
    $result .= "\n<input type='hidden' value='$symb' name='pssymb' />";
    $result .= "\n<input type='hidden' value='$paramlevel' name='parmlev' />";

    $result .= "<br /><br /><center><input type='submit' value='".&mt('Finish Helper')."' /></center></form>\n";

    return $result;
}
    
sub overrideForm {
    return 1;
}

1;

__END__