loncom/interface/lonhelper.pm - diff

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Diff for /loncom/interface/lonhelper.pm between versions 1.22 and 1.26

version 1.22, 2003/05/07 18:48:15	version 1.26, 2003/05/08 20:10:49
Line 193 my $substate;	Line 193 my $substate;
# end of the element tag is located.	# end of the element tag is located.
my $paramHash;	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 seperate 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. 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	# For debugging purposes, one can send a second parameter into this
# function, the 'uri' of the helper you wish to have rendered, and	# function, the 'uri' of the helper you wish to have rendered, and
# call this from other handlers.	# call this from other handlers.
sub handler {	sub real_handler {
my $r = shift;	my $r = shift;
my $uri = shift;	my $uri = shift;
if (!defined($uri)) { $uri = $r->uri(); }	if (!defined($uri)) { $uri = $r->uri(); }
Line 315 sub new {	Line 343 sub new {

$self->{TITLE} = shift;	$self->{TITLE} = shift;

	Apache::loncommon::get_unprocessed_cgi($ENV{QUERY_STRING});

# If there is a state from the previous form, use that. If there is no	# If there is a state from the previous form, use that. If there is no
# state, use the start state parameter.	# state, use the start state parameter.
if (defined $ENV{"form.CURRENT_STATE"})	if (defined $ENV{"form.CURRENT_STATE"})
Line 326 sub new {	Line 356 sub new {
$self->{STATE} = "START";	$self->{STATE} = "START";
}	}

Apache::loncommon::get_unprocessed_cgi($ENV{QUERY_STRING});

$self->{TOKEN} = $ENV{'form.TOKEN'};	$self->{TOKEN} = $ENV{'form.TOKEN'};
# If a token was passed, we load that in. Otherwise, we need to create a	# If a token was passed, we load that in. Otherwise, we need to create a
# new storage file	# new storage file
Line 690 the helper variables, like this:	Line 718 the helper variables, like this:

=back	=back

	B<finalcode tag>

	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.

	B<defaultvalue tag>

	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 wizard, 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.

=cut	=cut

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

# Because we use the param hash, this is often a sufficent	# Because we use the param hash, this is often a sufficent
Line 729 sub start_nextstate {	Line 784 sub start_nextstate {

sub end_nextstate { 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 ''; }

sub preprocess {	sub preprocess {
return 1;	return 1;
}	}
Line 875 the result is stored in.	Line 960 the result is stored in.
<choices> takes an attribute "multichoice" which, if set to a true	<choices> takes an attribute "multichoice" which, if set to a true
value, will allow the user to select multiple choices.	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.

B<SUB-TAGS>	B<SUB-TAGS>

<choices> can have the following subtags:	<choices> can have the following subtags:
Line 924 You can mix and match methods of creatin	Line 1013 You can mix and match methods of creatin
"push" onto the choice list, rather then wiping it out. (You can even	"push" onto the choice list, rather then wiping it out. (You can even
remove choices programmatically, but that would probably be bad form.)	remove choices programmatically, but that would probably be bad form.)

	B<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	=cut

no strict;	no strict;
Line 949 sub start_choices {	Line 1050 sub start_choices {
}	}

# Need to initialize the choices list, so everything can assume it exists	# Need to initialize the choices list, so everything can assume it exists
$paramHash->{'variable'} = $token->[2]{'variable'};	$paramHash->{'variable'} = $token->[2]{'variable'} if (!defined($paramHash->{'variable'}));
$helper->declareVar($paramHash->{'variable'});	$helper->declareVar($paramHash->{'variable'});
$paramHash->{'multichoice'} = $token->[2]{'multichoice'};	$paramHash->{'multichoice'} = $token->[2]{'multichoice'};
	$paramHash->{'allowempty'} = $token->[2]{'allowempty'};
$paramHash->{CHOICES} = [];	$paramHash->{CHOICES} = [];
return '';	return '';
}	}
Line 1007 sub render {	Line 1109 sub render {
}	}
</script>	</script>
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) {
$buttons = <<BUTTONS;	$buttons = <<BUTTONS;
<br />	<br />
<input type="button" onclick="checkall(true, '$var')" value="Select All" />	<input type="button" onclick="checkall(true, '$var')" value="Select All" />
Line 1023 BUTTONS	Line 1130 BUTTONS

$result .= "<table>\n\n";	$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 ' .
	{'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";	my $type = "radio";
if ($self->{'multichoice'}) { $type = 'checkbox'; }	if ($self->{'multichoice'}) { $type = 'checkbox'; }
my $checked = 0;
foreach my $choice (@{$self->{CHOICES}}) {	foreach my $choice (@{$self->{CHOICES}}) {
$result .= "<tr>\n<td width='20'> </td>\n";	$result .= "<tr>\n<td width='20'> </td>\n";
$result .= "<td valign='top'><input type='$type' name='$var.forminput'"	$result .= "<td valign='top'><input type='$type' name='$var.forminput'"
. "' value='" .	. "' value='" .
HTML::Entities::encode($choice->[1])	HTML::Entities::encode($choice->[1])
. "'";	. "'";
if (!$self->{'multichoice'} && !$checked) {	if ($checkedChoices{$choice->[1]}) {
$result .= " checked ";	$result .= " checked ";
$checked = 1;
}	}
my $choiceLabel = $choice->[0];	my $choiceLabel = $choice->[0];
if ($choice->[4]) { # if we need to evaluate this choice	if ($choice->[4]) { # if we need to evaluate this choice
Line 1057 sub postprocess {	Line 1198 sub postprocess {
my $self = shift;	my $self = shift;
my $chosenValue = $ENV{'form.' . $self->{'variable'} . '.forminput'};	my $chosenValue = $ENV{'form.' . $self->{'variable'} . '.forminput'};

if (!$chosenValue) {	if (!defined($chosenValue) && !$self->{'allowempty'}) {
$self->{ERROR_MSG} = "You must choose one or more choices to" .	$self->{ERROR_MSG} = "You must choose one or more choices to" .
" continue.";	" continue.";
return 0;	return 0;
Line 1866 SCRIPT	Line 2007 SCRIPT
<br />	<br />
<input type="button" onclick="checkall(true, '$var')" value="Select All Files" />	<input type="button" onclick="checkall(true, '$var')" value="Select All Files" />
<input type="button" onclick="checkall(false, '$var')" value="Unselect All Files" />	<input type="button" onclick="checkall(false, '$var')" value="Unselect All Files" />
	BUTTONS

	if ($helper->{VARS}->{'construction'}) {
	$buttons .= <<BUTTONS;
<input type="button" onclick="checkallclass(true, 'Published')" value="Select All Published" />	<input type="button" onclick="checkallclass(true, 'Published')" value="Select All Published" />
<input type="button" onclick="checkallclass(false, 'Published')" value="Unselect All Published" />	<input type="button" onclick="checkallclass(false, 'Published')" value="Unselect All Published" />
<br />	<br />
BUTTONS	BUTTONS
	}
}	}

# Get the list of files in this directory.	# Get the list of files in this directory.
Line 1904 BUTTONS	Line 2050 BUTTONS
}	}
my $fileName = $subdir .'/'. $file;	my $fileName = $subdir .'/'. $file;
if (&$filterFunc($file)) {	if (&$filterFunc($file)) {
(my $status, my $color) = @{fileState($subdir, $file)};	my $status;
	my $color;
	if ($helper->{VARS}->{'construction'}) {
	($status, $color) = @{fileState($subdir, $file)};
	} else {
	$status = '';
	$color = '';
	}

# Netscape 4 is stupid and there's nowhere to put the	# Netscape 4 is stupid and there's nowhere to put the
# information on the input tag that the file is Published,	# information on the input tag that the file is Published,
Line 1920 BUTTONS	Line 2073 BUTTONS
# couldn't figure out how to reach into the event handler's	# couldn't figure out how to reach into the event handler's
# actual code to retreive a value), but it works well enough	# actual code to retreive a value), but it works well enough
# here.	# here.

my $onclick = '';	my $onclick = '';
if ($status eq 'Published') {	if ($status eq 'Published' && $helper->{VARS}->{'construction'}) {
$onclick = 'onclick="a=1" ';	$onclick = 'onclick="a=1" ';
}	}
$result .= '<tr><td align="right"' . " bgcolor='$color'>" .	$result .= '<tr><td align="right"' . " bgcolor='$color'>" .

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Removed from v.1.22
changed lines
	Added in v.1.26