# The LearningOnline Network with CAPA
# Directory Indexer
#
# $Id: lonindexer.pm,v 1.177 2007/08/17 21:33:19 banghart 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/
#
###

###############################################################################
##                                                                           ##
## ORGANIZATION OF THIS PERL MODULE                                          ##
##                                                                           ##
## 1. Description of functions                                               ##
## 2. Modules used by this module                                            ##
## 3. Choices for different output views (detailed, summary, xml, etc)       ##
## 4. BEGIN block (to be run once after compilation)                         ##
## 5. Handling routine called via Apache and mod_perl                        ##
## 6. Other subroutines                                                      ##
##                                                                           ##
###############################################################################

package Apache::lonindexer;

# ------------------------------------------------- modules used by this module
use strict;
use Apache::lonnet;
use Apache::loncommon();
use Apache::lonhtmlcommon();
use Apache::lonsequence();
use Apache::Constants qw(:common);
use Apache::lonmeta;
use Apache::File;
use Apache::lonlocal;
use Apache::lonsource();
use Apache::groupsort();
use GDBM_File;
use LONCAPA qw(:match);

# ---------------------------------------- variables used throughout the module
my %hash; # global user-specific gdbm file
my %dirs; # keys are directories, values are the open/close status
my %language; # has the reference information present in language.tab
my %dynhash; # hash of hashes for dynamic metadata
my %dynread; # hash of directories already read for dynamic metadata
my %fieldnames; # Metadata fieldnames
# ----- Values which are set by the handler subroutine and are accessible to
# -----     other methods.
my $extrafield; # default extra table cell
my $fnum; # file counter
my $dnum; # directory counter

# ----- Used to include or exclude files with certain extensions.
my @Only = ();
my @Omit = ();




# ----------------------------- Handling routine called via Apache and mod_perl
sub handler {
    my $r = shift;
    my $c = $r->connection();
    &Apache::loncommon::content_type($r,'text/html');
    &Apache::loncommon::no_cache($r);
    $r->send_http_header;
    return OK if $r->header_only;
    $fnum=0;
    $dnum=0;

    # Deal with stupid global variables (is there a way around making
    # these global to this package?  It is just so wrong....)
    undef (@Only);
    undef (@Omit);
    %fieldnames=&Apache::lonmeta::fieldnames();

# ------------------------------------- read in machine configuration variables
    my $iconpath= $r->dir_config('lonIconsURL') . "/";
    my $domain  = $r->dir_config('lonDefDomain');
    my $role    = $r->dir_config('lonRole');
    my $loadlim = $r->dir_config('lonLoadLim');
    my $servadm = $r->dir_config('lonAdmEMail');
    my $sysadm  = $r->dir_config('lonSysEMail');
    my $lonhost = $r->dir_config('lonHostID');
    my $tabdir  = $r->dir_config('lonTabDir');

    my $fileclr='#ffffe6';
    my $line;
    my (@attrchk,@openpath,$typeselect);
    my $uri=$r->uri;

# -------------------------------------- see if called from an interactive mode
    # Get the parameters from the query string
    &Apache::loncommon::get_unprocessed_cgi($ENV{'QUERY_STRING'},
	     ['catalogmode','launch','acts','mode','form','element',
              'only','omit','titleelement']);
    #-------------------------------------------------------------------
    my $closebutton='';
    my $groupimportbutton='';
    my $colspan=''; 
    
    $extrafield='';
    my $diropendb = 
	"/home/httpd/perl/tmp/$env{'user.domain'}_$env{'user.name'}_sel_res.db";
    %hash = ();
    {
	my %dbfile;
	if (tie(%dbfile,'GDBM_File',$diropendb,&GDBM_WRITER(),0640)) {
	    if ($env{'form.launch'} eq '1') {
		&start_fresh_session(\%dbfile);
	    }
	    while(my($key,$value)=each(%dbfile)) {
		$hash{$key}=$value;
	    }
	    untie(%dbfile);
	}
    }
# - Evaluate actions from previous page (both cumulatively and chronologically)
        if ($env{'form.catalogmode'} eq 'import' || $hash{'form.catalogmode'} eq 'import') {
	    &Apache::groupsort::update_actions_hash(\%hash);
	}
    
    {
  #Hijack lonindexer to verify a title and be close down.
   if ($env{'form.launch'} eq '2') {
       &Apache::loncommon::content_type($r,'text/html');
       my $extra='';
       if (defined($env{'form.titleelement'}) && 
	   $env{'form.titleelement'} ne '') {
	   my $verify_title = &Apache::lonnet::gettitle($env{'form.acts'});
#	   &Apache::lonnet::logthis("Hrrm $env{'form.acts'} -- $verify_title");
	   $verify_title=~s/'/\\'/g;
	   $extra='window.opener.document.forms["'.$env{'form.form'}.'"].elements["'.$env{'form.titleelement'}.'"].value=\''.$verify_title.'\';';
       }
       my $js = <<ENDSUBM;
	       <script type="text/javascript">
		function load() {
			window.opener.document.forms["$env{'form.form'}"]
			    .elements["$env{'form.element'}"]
			    .value='$env{'form.acts'}';
			$extra
			window.close();
		}
   	       </script>
ENDSUBM
       $r->print(&Apache::loncommon::start_page(undef,$js,
						{'only_body'   =>1,
						 'add_entries' =>
						     {'onload' => "load();"},}
						).
		 &Apache::loncommon::end_page());
       return OK;
   }
    
# -------------------- refresh environment with user database values (in %hash)
	&setvalues(\%hash,'form.catalogmode',\%env,'form.catalogmode'   );

# --------------------- define extra fields and buttons in case of special mode
	if ($env{'form.catalogmode'} eq 'interactive') {
	    $extrafield='<td bgcolor="'.$fileclr.'" valign="bottom">'.
		'<img alt="" src="'.$iconpath.'whitespace1.gif"'.
		' class="LC_icon" /></td>';
	    $colspan=" colspan='2' ";
            my $cl=&mt('Close');
            $closebutton=<<END;
<input type="button" name="close" value='$cl' onClick="self.close()" />
END
        }
	elsif ($env{'form.catalogmode'} eq 'import') {
	    $extrafield='<td bgcolor="'.$fileclr.'" valign="bottom">'.
		'<img alt="" src="'.$iconpath.'whitespace1.gif"'.
		' class="LC_icon" /></td>';
	    $colspan=" colspan='2' ";
	    my $cl=&mt('Close');
            my $gi=&mt('Import');
            $closebutton=<<END;
<input type="button" name="close" value='$cl' onClick="self.close()" />
END
            $groupimportbutton=<<END;
<input type="button" name="groupimport" value='$gi'
onClick="javascript:select_group()" />
END
        }
	# Additions made by Matthew to make the browser a little easier to deal
	# with in the future.
	#
	# $mode (at this time) indicates if we are in edit mode.
	# $form is the name of the form that the URL is placed when the
	#       selection is made.
	# $element is the name of the element in $formname which receives
	#       the URL.
	#&Apache::lonxml::debug('Checking mode, form, element');
	&setvalues(\%hash,'form.mode'        ,\%env,'form.mode'   );
	&setvalues(\%hash,'form.form'        ,\%env,'form.form'   );
	&setvalues(\%hash,'form.element'     ,\%env,'form.element');
	&setvalues(\%hash,'form.titleelement',\%env,'form.titleelement');
	&setvalues(\%hash,'form.only'        ,\%env,'form.only'   );
	&setvalues(\%hash,'form.omit'        ,\%env,'form.omit'   );

        # Deal with 'omit' and 'only' 
        if (exists $env{'form.omit'}) {
            @Omit = split(',',$env{'form.omit'});
        }
        if (exists $env{'form.only'}) {
            @Only = split(',',$env{'form.only'});
        }
        
	my $mode = $env{'form.mode'};
	my ($form,$element,$titleelement);
	if ($mode eq 'edit' || $mode eq 'parmset') {
	    $form         = $env{'form.form'};
	    $element      = $env{'form.element'};
	    $titleelement = $env{'form.titleelement'};
	}
	#&Apache::lonxml::debug("mode=$mode form=$form element=$element titleelement=$titleelement");
# ------ set catalogmodefunctions to have extra needed javascript functionality
	my $catalogmodefunctions='';
	if ($env{'form.catalogmode'} eq 'interactive' or
	    $env{'form.catalogmode'} eq 'import') {
	    # The if statement below sets us up to use the old version
	    # by default (ie. if $mode is undefined).  This is the easy
	    # way out.  Hopefully in the future I'll find a way to get 
	    # the calls dealt with in a more comprehensive manner.

#
# There is now also mode "simple", which is for the simple version of the rat
#
#
	    if (!defined($mode) || ($mode ne 'edit' && $mode ne 'parmset')) {
                my $location = "/adm/groupsort?&inhibitmenu=yes&catalogmode=import&";
                $location .= "mode=".$mode."&";
                $location .= "acts=";
		$catalogmodefunctions=<<"END";
function select_data(url) {
    changeURL(url);
    self.close();
}
function select_group() {
    window.location="$location"+document.forms.fileattr.acts.value;
}
function changeURL(val) {
    if (opener.inf) {
        if (opener.inf.document.forms.resinfo.elements.u) {
	    opener.inf.document.forms.resinfo.elements.u.value=val;
        }
    }
}
END
            } elsif ($mode eq 'edit') { # we are in 'edit' mode
                my $location = "/adm/groupsort?catalogmode=interactive&";
                $location .= "form=$form&element=$element&mode=edit&acts=";
		$catalogmodefunctions=<<END;
// mode = $mode
function select_data(url) {
   var location = "/res/?launch=2&form=$form&element=$element&titleelement=$titleelement&acts=" + url;
   window.location=location;
   if (window.opener.document.forms["$form"].elements["$element"].value != url) {
       window.opener.unClean();
   }
}
function select_group() {
    window.location="$location"+document.forms.fileattr.acts.value;
}

function changeURL(val) {
    if (window.opener.document) {
	window.opener.document.forms["$form"].elements["$element"].value=val;
    } else {
	    alert("The file you selected is: "+val);
    }
}
END
                if (!$titleelement) {
		    $catalogmodefunctions.='function changeTitle(val) {}';
		} else {
		    $catalogmodefunctions.=<<END;
function changeTitle(val) {
    if (window.opener.document) {
	    window.opener.document.forms["$form"].elements["$titleelement"].value=val;
    } else {
	    alert("The title of the file you selected is: "+val);
    }
}
END
                }
            } elsif ($mode eq 'parmset') {
                my $location = "/adm/groupsort?catalogmode=interactive&";
                $location .= "form=$form&element=$element&mode=parmset&acts=";
		$catalogmodefunctions=<<END;
// mode = $mode
function select_data(url) {
    changeURL(url);
    self.close();
}

function select_group() {
    window.location="$location"+document.forms.fileattr.acts.value;
}

function changeURL(val) {
    if (window.opener.document) {
        var elementname  = "$element"+"_value";
        var checkboxname = "$element"+"_setparmval";
	window.opener.document.forms["$form"].elements[elementname].value=val;
        window.opener.document.forms["$form"].elements[checkboxname].checked=true;
    } else {
	    alert("The file you selected is: "+val);
    }
}

END
            }
        }
        $catalogmodefunctions.=<<END;
var acts='';
function rep_dirpath(suffix,val) {
    eval("document.forms.dirpath"+suffix+".acts.value=val");
}
END
	if ($env{'form.catalogmode'} eq 'import') {
            $catalogmodefunctions.=<<END;
function queue(val) {
    if (eval("document.forms."+val+".filelink.checked")) {
	var l=val.length;
	var v=val.substring(4,l);
	document.forms.fileattr.acts.value+='1a'+v+'b';
    }
    else {
	var l=val.length;
	var v=val.substring(4,l);
	document.forms.fileattr.acts.value+='0a'+v+'b';
    }
}
END
	}

        my $inhibit_menu = "+'&".&Apache::loncommon::inhibit_menu_check()."'";
# ---------------------------------------------------------------- Print Header
        
	my $js = <<"ENDHEADER";
<script type="text/javascript">
$catalogmodefunctions;
function update_only(field) {
    alert(field.name);
}
function checkAll() {
    var numForms = document.forms.length;
    for (i=0;i<numForms;i++) {
        var numElements = document.forms[i].elements.length;
        for (j=0;j<numElements;j++){
            var fieldName = document.forms[i].elements[j].name;
            if (fieldName == 'filelink') {
                document.forms[i].elements[j].checked = true;
                queue(document.forms[i].name);
            }
        }
    }
}
function uncheckAll() {
    var numForms = document.forms.length;
    for (i=0;i<numForms;i++) {
        var numElements = document.forms[i].elements.length;
        for (j=0;j<numElements;j++){
            var fieldName = document.forms[i].elements[j].name;
            if (fieldName == 'filelink') {
                document.forms[i].elements[j].checked = false;
                queue(document.forms[i].name);
            }
        }
    }
}
function openWindow(url, wdwName, w, h, toolbar,scrollbar,locationbar) {
    var xpos = (screen.width-w)/2;
    xpos = (xpos < 0) ? '0' : xpos;
    var ypos = (screen.height-h)/2-30;
    ypos = (ypos < 0) ? '0' : ypos;
    var options = "width=" + w + ",height=" + h + ",screenx="+xpos+",screeny="+ypos+",";
    options += "resizable=yes,scrollbars="+scrollbar+",status=no,";
    options += "menubar=no,toolbar="+toolbar+",location="+locationbar+",directories=no";
    var newWin = window.open(url, wdwName, options);
    newWin.focus();
}
function gothere(val) {
    window.location=val+'?acts='+document.forms.fileattr.acts.value$inhibit_menu;
}
</script>
ENDHEADER

        my ($headerdom)=($uri=~m{^/res/($match_domain)/});
	$r->print(&Apache::loncommon::start_page('Browse Resources',$js,
						 {'domain' => $headerdom,}));
# ---------------------------------- get state of file types to be showing
	if ($env{'form.only'}) {
	    $typeselect = $env{'form.only'};
	} else {
	    $typeselect = '';
	}

# ---------------------------------- get state of file attributes to be showing
	if ($env{'form.attrs'}) {
	    for (my $i=0; $i<=11; $i++) {
		delete $hash{'display_attrs_'.$i};
		if ($env{'form.attr'.$i} == 1) {
		    $attrchk[$i] = 'checked';
		    $hash{'display_attrs_'.$i} = 1;
		}
	    }
	} else {
	    for (my $i=0; $i<=11; $i++) {
		$attrchk[$i] = 'checked' if $hash{'display_attrs_'.$i} == 1;
	    }
	}

# ------------------------------- output state of file attributes to be showing
#                                 All versions has to the last item
#                                 since it does not take an extra col
	my %lt=&Apache::lonlocal::texthash(
					   'ti' => 'Title',
					   'si' => 'Size',
					   'la' => 'Last access',
					   'lm' => 'Last modified',
					   'st' => 'Statistics',
					   'au' => 'Author',
					   'kw' => 'Keywords',
					   'ln' => 'Language',
					   'sa' => 'Source Available',
					   'sr' => 'Show resource',
					   'li' => 'Linked/Related Resources',
					   'av' => 'All versions',
					   'ud' => 'Update Display',
					   'pr' => 'Problems',
					   'gr' => 'Graphics',
					   'at' => 'All types'
					   );
	$r->print(<<END);
<form method="post" name="fileattr" action="$uri"
 enctype="application/x-www-form-urlencoded">
<label><input type="checkbox" name="attr9" value="1" $attrchk[9] onClick="this.form.submit();" /> $lt{'av'}</label>
<table border="0">
<tr>
<td><label><input type="checkbox" name="attr0" value="1" $attrchk[0] onClick="this.form.submit();" /> $lt{'ti'}</label></td>
<td><label><input type="checkbox" name="attr4" value="1" $attrchk[4] onClick="this.form.submit();" /> $lt{'au'}</label></td>
<td><label><input type="checkbox" name="attr5" value="1" $attrchk[5] onClick="this.form.submit();" /> $lt{'kw'}</label></td>
<td><label><input type="checkbox" name="attr6" value="1" $attrchk[6] onClick="this.form.submit();" /> $lt{'ln'}</label></td>
</tr>
<tr>
<td><label><input type="checkbox" name="attr1" value="1" $attrchk[1] onClick="this.form.submit();" /> $lt{'si'}</label></td>
<td><label><input type="checkbox" name="attr2" value="1" $attrchk[2] onClick="this.form.submit();" /> $lt{'la'}</label></td>
<td><label><input type="checkbox" name="attr3" value="1" $attrchk[3] onClick="this.form.submit();" /> $lt{'lm'}</label></td>
<td><label><input type="checkbox" name="attr10" value="1" $attrchk[10] onClick="this.form.submit();" /> $lt{'sa'}</label></td>
</tr>
<tr>
<td><label><input type="checkbox" name="attr8" value="1" $attrchk[8] onClick="this.form.submit();" /> $lt{'st'}</label></td>
<td><label><input type="checkbox" name="attr11" value="1" $attrchk[11] onClick="this.form.submit();" /> $lt{'li'}</label></td>
<td><label><input type="checkbox" name="attr7" value="1" $attrchk[7] onClick="this.form.submit();" /> $lt{'sr'}</label></td>
<td>&nbsp;</td>
</tr>
</table>
<input type="hidden" name="attrs" value="1" />
<label>
END
my @file_categories = &Apache::loncommon::filecategories();
my %select_file_categories;
my @select_form_order = ('');
$select_file_categories{''} = 'All file types';
foreach my $cat(@file_categories) {
    my $types = join ",",&Apache::loncommon::filecategorytypes($cat);
    $select_file_categories{$types} = $cat;
    push(@select_form_order,$types);
}
$select_file_categories{'select_form_order'} = [@select_form_order];
$r->print(&Apache::loncommon::select_form($typeselect,'only',
			%select_file_categories
			));
$r->print(<<END);
File Type Displayed</label>
<br />
<input type="submit" name="updatedisplay" value="$lt{'ud'}" />
<input type="hidden" name="acts" value="" />
$closebutton $groupimportbutton
END
        $r->print(&Apache::loncommon::inhibit_menu_check('input'));
# -------------- Filter out sequence containment in crumbs and "recent folders"
	my $storeuri=$uri;
	$storeuri='/'.(split(/\.(page|sequence)\/\//,$uri))[-1];
	$storeuri=~s/\/+/\//g;
# ---------------------------------------------------------------- Bread crumbs
        $r->print(&Apache::lonhtmlcommon::crumbs($storeuri,'','',
				(($env{'form.catalogmode'} eq 'import')?
				 'document.forms.fileattr':'')).
		  &Apache::lonhtmlcommon::select_recent('residx','resrecent',
'window.status=this.form.resrecent.options[this.form.resrecent.selectedIndex].value;this.form.action=this.form.resrecent.options[this.form.resrecent.selectedIndex].value;this.form.submit();'));
# -------------------------------------------------------- Resource Home Button
	my $reshome=$env{'course.'.$env{'request.course.id'}.'.reshome'};
	if ($reshome) {
	    $r->print("<font size='+2'><a href='");
	    if ($env{'form.catalogmode'} eq 'import') {
		$r->print('javascript:document.forms.fileattr.action="'.&Apache::loncommon::inhibit_menu_check($reshome).'";document.forms.fileattr.submit();');
	    } else {
		$r->print($reshome);
	    }
	    $r->print("'>".&mt('Home').'</a></font>');
	}
	$r->print('</form>');
# ------------------------------------------------------ Remember where we were
	&Apache::loncommon::storeresurl($storeuri);
	&Apache::lonhtmlcommon::store_recent('residx',$storeuri,$storeuri);
# -------------------------------------------------- Check All and Uncheck all
	if ($env{'form.catalogmode'} eq 'import') {
	    $r->print('<br /><input type="button" value="'.&mt("Check All").'" id="checkallbutton" onClick="javascript:checkAll()" />');
	    $r->print('<input type="button" value="'.&mt("Uncheck All").'" id="uncheckallbutton" onClick="javascript:uncheckAll()" />');
	}
# ----------------- output starting row to the indexed file/directory hierarchy
        my $titleclr="#ddffff";
        #$r->print(&initdebug());
        #$r->print(&writedebug("Omit:@Omit")) if (@Omit);
        #$r->print(&writedebug("Only:@Only")) if (@Only);
        $r->print('<table width="100%" border="0"><tr><td bgcolor="#777777">'."\n");
	$r->print('<table width="100%" border="0"><tr bgcolor="'.$titleclr.'">'."\n");
	$r->print("<td $colspan><b>".&mt('Name')."</b></td>\n");
	$r->print("<td><b>".&mt('Title')."</b></td>\n") 
	    if ($hash{'display_attrs_0'} == 1);
	$r->print("<td align=right><b>".&mt("Size")." (".&mt("bytes").") ".
		  "</b></td>\n") if ($hash{'display_attrs_1'} == 1);
	$r->print("<td><b>".&mt("Last accessed")."</b></td>\n") 
	    if ($hash{'display_attrs_2'} == 1);
	$r->print("<td><b>".&mt("Last modified")."</b></td>\n")
	    if ($hash{'display_attrs_3'} == 1);
	$r->print("<td><b>".&mt("Author(s)")."</b></td>\n")
	    if ($hash{'display_attrs_4'} == 1);
	$r->print("<td><b>".&mt("Keywords")."</b></td>\n")
	    if ($hash{'display_attrs_5'} == 1);
	$r->print("<td><b>".&mt("Language")."</b></td>\n")
	    if ($hash{'display_attrs_6'} == 1);
	$r->print("<td><b>".&mt("Usage Statistics")." <br />(".
		  &mt("Courses/Network Hits").")</b> ".&mt('updated periodically')."</td>\n")
	    if ($hash{'display_attrs_8'} == 1);
	$r->print("<td><b>".&mt("Source Available")."</b></td>\n")
	    if ($hash{'display_attrs_10'} == 1);
	$r->print("<td><b>".&mt("Linked/Related Resources")."</b></td>\n")
	    if ($hash{'display_attrs_11'} == 1);
	$r->print("<td><b>".&mt("Resource")."</b></td>\n")
	    if ($hash{'display_attrs_7'} == 1);
	$r->print('</tr>');

# ----------------- read in what directories have previously been set to "open"
	foreach (keys %hash) {
	    if ($_ =~ /^diropen_status_/) {
		my $key = $_;
		$key =~ s/^diropen_status_//;
		$dirs{$key} = $hash{$_};
	    }
	}

	if ($env{'form.openuri'}) {  # take care of review and refresh options
	    my $uri=$env{'form.openuri'};
	    if (exists($hash{'diropen_status_'.$uri})) {
		my $cursta = $hash{'diropen_status_'.$uri};
		$dirs{$uri} = 'open';
		$hash{'diropen_status_'.$uri} = 'open';
		if ($cursta eq 'open') {
		    $dirs{$uri} = 'closed';
		    $hash{'diropen_status_'.$uri} = 'closed';
		}
	    } else {
		$hash{'diropen_status_'.$uri} = 'open';
		$dirs{$uri} = 'open';
	    }
	}
	
	my $toplevel;
	my $indent = 0;
	$uri = $uri.'/' if $uri !~ /.*\/$/;

 	if ($env{'form.dirPointer'} ne 'on') {
 	    $hash{'top.level'} = $uri;
 	    $toplevel = $uri;
 	} else {
 	    $toplevel = $hash{'top.level'};
 	}

# -------------------------------- if not at top level, provide an uplink arrow
	if ($toplevel ne '/res/'){
	    my (@uri_com) = split(/\//,$uri);
	    pop @uri_com;
	    my $upone = join('/',@uri_com);
	    my @list = qw (0);
	    &display_line ($r,'opened',$upone.'&viewOneUp',0,$upone,@list);
	    $indent = 1;
	}

# -------- recursively go through all the directories and output as appropriate
	&scanDir ($r,$toplevel,$indent,\%hash);
	

# -------------------------------------------------------------- end the tables
	$r->print('</table>');
# ---------------------------- embed hidden information useful for group import
	$r->print("<form name='fnum' action=''>");
	$r->print("<input type='hidden' name='fnum' value='$fnum' /></form>");
# -------------------------------------------------------------- end the tables
	$r->print('</td></tr></table>');

# --------------------------------------------------- end the output and return
	$r->print(&Apache::loncommon::end_page()."\n");
    }
    if(! $c->aborted()) {
# write back into the temporary file
	my %dbfile;
        if (tie(%dbfile,'GDBM_File',$diropendb,&GDBM_NEWDB(),0640)) {
            while (my($key,$value) = each(%hash)) {
                $dbfile{$key}=$value;
            }
            untie(%dbfile);
        }
    }

    return OK;
}

# ----------------------------------------------- recursive scan of a directory
sub scanDir {
    my ($r,$startdir,$indent,$hashref)=@_;
    my $c = $r->connection();
    my ($compuri,$curdir);
    my $dirptr=16384;
    my $obs;
    $indent++;
    my %dupdirs = %dirs;
    my @list=&get_list($r,$startdir);
    foreach my $line (@list) {
        return if ($c->aborted());
	#This is a kludge, sorry aboot this
	my ($strip,$dom,undef,$testdir,undef,undef,undef,undef,undef,undef,undef,undef,undef,undef,$obs,undef)=split(/\&/,$line,16); 
	next if($strip =~ /.*\.meta$/ | $obs eq '1');
	my (@fileparts) = split(/\./,$strip);
	if ($hash{'display_attrs_9'} != 1) {
# if not all versions to be shown
	    if (scalar(@fileparts) >= 3) {
		my $fext = pop @fileparts;
		my $ov = pop @fileparts;
		my $fname = join ('.',@fileparts,$fext);
		next if (grep /\Q$fname\E/,@list and $ov =~ /^\d+$/);
	    }
	}

	if ($dom eq 'domain') {
	    # dom list has full path /res/<domain name>/ already
	    $curdir='';
	    $compuri = (split(/\&/,$line))[0];
	} else {
	    # user, dir & file have name only, i.e., w/o path
	    $compuri = join('',$startdir,$strip,'/');
	    $curdir = $startdir;
	}
	my $diropen = 'closed';
	if (($dirptr&$testdir) or ($dom =~ /^(domain|user)$/) or ($compuri=~/\.(sequence|page)\/$/)) {
	    while (my ($key,$val)= each %dupdirs) {
		if ($key eq $compuri and $val eq "open") {
		    $diropen = "opened";
		    delete($dupdirs{$key});
		    delete($dirs{$key});
		}
	    }
	}
	&display_line($r,$diropen,$line,$indent,$curdir,$hashref,@list);
	&scanDir ($r,$compuri,$indent) if $diropen eq 'opened';
    }
    $indent--;
}

# --------------- get complete matched list based on the uri (returns an array)
sub get_list {
    my ($r,$uri)=@_;
    my @list=();
    (my $luri = $uri) =~ s/\//_/g;
    if ($env{'form.updatedisplay'}) {
	foreach (keys %hash) {
	    delete $hash{$_} if ($_ =~ /^dirlist_files_/);
	    delete $hash{$_} if ($_ =~ /^dirlist_timestamp_files_/);
	}
    }

    if (defined($hash{'dirlist_files_'.$luri}) &&
	$hash{'dirlist_timestamp_files_'.$luri}+600 > (time)) {
	@list = split(/\n/,$hash{'dirlist_files_'.$luri});
    } elsif ($uri=~/\.(page|sequence)\/$/) {
# is a page or a sequence
	$uri=~s/\/$//;
	$uri='/'.(split(/\.(page|sequence)\/\//,$uri))[-1];
	$uri=~s/\/+/\//g;
	foreach (&Apache::lonsequence::attemptread(&Apache::lonnet::filelocation('',$uri))) {
	    my @ratpart=split(/\:/,$_);
	    push(@list,&LONCAPA::map::qtescape($ratpart[1]));
	} 
	$hash{'dirlist_files_'.$luri} = join("\n",@list);
    } else {
# is really a directory
	@list = &Apache::lonnet::dirlist($uri);
	$hash{'dirlist_files_'.$luri} = join("\n",@list);
	$hash{'dirlist_timestamp_files_'.$luri} = time;
    }
    return @list=&match_ext($r,@list);    
}

sub dynmetaread {
    my $uri=shift;
    if (($hash{'display_attrs_8'}==1) || ($hash{'display_attrs_11'}==1)) {
# We don't want the filename
	$uri=~s/\/[^\/]+$//;
# Did we already see this?
	my $builddir=$uri;
	while ($builddir) {
	    if ($dynread{$builddir}) {
		return 0;
	    }
	    $builddir=~s/\/[^\/]+$//;
	}
# Actually get the data
	%dynhash=
	    (%dynhash,&Apache::lonmeta::get_dynamic_metadata_from_sql($uri.'/'));
# Remember that we got it
	$dynread{$uri}=1;
    } 
}

sub initdebug {
    my $start_page=
	&Apache::loncommon::start_page('Debug',undef,
				       {'only_body' => 1,});
    $start_page =~ s/\n/ /g;
    return <<ENDJS;
<script type="text/javascript">
var debugging = true;
if (debugging) {
    var debuggingWindow = window.open('','Debug','width=400,height=300',true);
} 

function output(text) {
    if (debugging) {
        debuggingWindow.document.writeln(text);
    }
}
output('$start_page<pre>');   
</script>
ENDJS
}

sub writedebug {
    my ($text) = @_;
    return "<script type=\"text/javascript\">output('$text');</script>";
}

# -------------------- filters out files based on extensions (returns an array)
sub match_ext {
    my ($r,@packlist)=@_;
    my @trimlist;
    my $nextline;
    my @fileext;
    my $dirptr=16384;

    foreach my $line (@packlist) {
	chomp $line;
	$line =~ s/^\/home\/httpd\/html//;
	my @unpackline = split (/\&/,$line);
	next if ($unpackline[0] eq '.');
	next if ($unpackline[0] eq '..');
	my @filecom = split (/\./,$unpackline[0]);
	my $fext = pop(@filecom);
	my $fnptr = ($unpackline[3]&$dirptr) || ($fext=~/\.(page|sequence)$/);
 	if ($fnptr == 0 and $unpackline[3] ne "") {
	    my $embstyle = &Apache::loncommon::fileembstyle($fext);
            push @trimlist,$line if (defined($embstyle) && 
				     ($embstyle ne 'hdn' or $fext eq 'meta'));
	} else {
	    push @trimlist,$line;
	}
    }
    @trimlist = sort {uc($a) cmp uc($b)} (@trimlist);
    return @trimlist;
}

# ------------------------------- displays one line in appropriate table format
sub display_line {
    my ($r,$diropen,$line,$indent,$startdir,$hashref,@list)=@_;
    my (@pathfn, $fndir);
# there could be relative paths (files actually belonging into this directory)
# or absolute paths (for example, from sequences)
    my $absolute;
    my $pathprefix;
    if ($line=~m|^/res/| && $startdir ne '') {
	$absolute=1;
	$pathprefix='';
    } else {
	$absolute=0;
	$pathprefix=$startdir;
    }
    my $dirptr=16384;
    my $fileclr="#ffffe6";
    my $iconpath= $r->dir_config('lonIconsURL') . '/';

    my @filecom = split (/\&/,$line);
    my @pathcom = split (/\//,$filecom[0]);
    my $listname = $pathcom[scalar(@pathcom)-1];
    my $fnptr = $filecom[3]&$dirptr;
    my $msg = &mt('View').' '.$filecom[0].' '.&mt('resources');
    $msg = &mt('Close').' '.$filecom[0].' '.&mt('directory') if $diropen eq 'opened';

    my $tabtag='</td>';
    my $i=0;
    while ($i<=11) {
	$tabtag=join('',$tabtag,"<td>&nbsp;</td>")
	    if ($i != 9 &&
		$hash{'display_attrs_'.$i} == 1);
	$i++;
    }
    my $valign = ($hash{'display_attrs_7'} == 1 ? 'top' : 'bottom');

# display uplink arrow
    if ($filecom[1] eq 'viewOneUp') {
	my $updir=$startdir;
# -------------- Filter out sequence containment in crumbs and "recent folders"
	$updir='/'.(split(/\.(page|sequence)\/\//,$startdir))[-1];
	$updir=~s/\/+/\//g;

	$r->print("<tr valign='$valign' bgcolor=\"$fileclr\">$extrafield");
	$r->print("<td>\n");
	$r->print ('<form method="post" name="dirpathUP" action="'.$updir.
		   '/" '.
		   'onSubmit="return rep_dirpath(\'UP\','.
		   'document.forms.fileattr.acts.value)" '.
		   'enctype="application/x-www-form-urlencoded"'.
                   '>'."\n");
	$r->print(&Apache::loncommon::inhibit_menu_check('input'));
	$r->print ('<input type=hidden name=openuri value="'.
		   $startdir.'" />'."\n");
	$r->print ('<input type="hidden" name="acts" value="" />'."\n");
	$r->print ('<input src="'.$iconpath.'arrow_up.gif"');
	$r->print (' name="'.$msg.'" type="image" class="LC_indexer_icon" />'.
		   "\n");
	$r->print(&mt("Up")."</form>$tabtag</tr>\n");
	return OK;
    }
# Do we have permission to look at this?

    if($filecom[15] ne '1') { return OK if (!&Apache::lonnet::allowed('bre',$pathprefix.$filecom[0])); }

# make absolute links appear on different background
    if ($absolute) { $fileclr='#ccdd99'; }

# display domain
    if ($filecom[1] eq 'domain') {
 	$r->print ('<input type="hidden" name="dirPointer" value="on" />'."\n")
 	    if ($env{'form.dirPointer'} eq "on");
	$r->print("<tr valign='$valign' bgcolor=\"$fileclr\">$extrafield");
	$r->print("<td>");
	&begin_form ($r,$filecom[0]);
	my $anchor = $filecom[0];
	$anchor =~ s/\W//g;
	$r->print ('<a name="'.$anchor.'"></a>');
	$r->print ('<input type="hidden" name="acts" value="" />');
	$r->print ('<input src="'.$iconpath.'folder_pointer_'.
		   $diropen.'.gif"'); 
	$r->print (' name="'.$msg.'" type="image" class="LC_indexer_icon" />'.
		   "\n");
	my $quotable_filecom = &Apache::loncommon::escape_single($filecom[0]);
	$r->print ('<a href="javascript:gothere(\''.$quotable_filecom.
		   '\')"><img alt="" src="'.$iconpath.'server.gif"');
	$r->print (' class="LC_icon" /></a>'."\n");
	$r->print (&mt("Domain")." - $listname ");
	if (&Apache::lonnet::domain($listname,'description')) {
	    $r->print("(".&Apache::lonnet::domain($listname,'description').
		      ")");
	}
	$r->print ("</form>$tabtag</tr>\n");
	return OK;

# display user directory
    }
    if ($filecom[1] eq 'user') {
	# $r->print("<tr valign=$valign bgcolor=\"$fileclr\">$extrafield");
	my $curdir = $startdir.$filecom[0].'/';
	my $anchor = $curdir;
	$anchor =~ s/\W//g;
	$r->print("<tr bgcolor=\"$fileclr\">$extrafield<td valign=$valign>");
	&begin_form ($r,$curdir);
	$r->print ('<a name="'.$anchor.'"></a><img alt="" src="'.$iconpath.
		   'whitespace1.gif" class="LC_icon" />'."\n");
	$r->print ('<input type="hidden" name="acts" value="" />');
	$r->print ('<input src="'.$iconpath.'folder_pointer_'.$diropen.
		   '.gif"'); 
	$r->print (' name="'.$msg.'" type="image" class="LC_indexer_icon" />'.
		   "\n");
	my $quotable_curdir = &Apache::loncommon::escape_single($curdir);
	$r->print ('<a href="javascript:gothere(\''.$quotable_curdir
		   .'\')"><img alt="'.$msg.'" src="'.
		   $iconpath.'quill.gif" class="LC_indexer_icon" /></a>');
	my $domain=(split(m|/|,$startdir))[2];
	my $plainname=&Apache::loncommon::plainname($listname,$domain);
	$r->print ($listname);
	if (defined($plainname) && $plainname) { $r->print(" ($plainname) "); }
	$r->print ('</form>'.$tabtag.'</tr>'."\n");
	return OK;
    }

# display file
    if (($fnptr == 0 and $filecom[3] ne '') or $absolute) {
        my $title;
	my $filelink = $pathprefix.$filecom[0];
	if ($hash{'display_attrs_0'} == 1) {
	    $title = &Apache::lonnet::gettitle($filelink);
	}
	my @file_ext = split (/\./,$listname);
	my $curfext = $file_ext[-1];
        if (@Omit) {
            foreach (@Omit) { return OK if ($curfext eq $_); }
        }
        if (@Only) {
            my $skip = 1;
            foreach (@Only) { $skip = 0 if ($curfext eq $_); }
            return OK if ($skip > 0);
        }
	# Set the icon for the file
	my $iconname = &Apache::loncommon::icon($listname);
	$r->print("<tr valign='$valign' bgcolor=\"$fileclr\"><td nowrap='nowrap' valign='top'>");
	
        if ($env{'form.catalogmode'} eq 'interactive') {
	    my $quotable_filelink = &Apache::loncommon::escape_single($filelink);
            $r->print("<a href=\"javascript:select_data(\'",
                      $quotable_filelink,"')\">");
	    $r->print("<img alt=\"\" src='",$iconpath,"select.gif' class='LC_icon' /></a>".
		      "\n");
	    $r->print("</td><td nowrap='nowrap' valign='top'>");
	} elsif ($env{'form.catalogmode'} eq 'import') {
	    $r->print("<form name='form$fnum' action=''>\n");
	    $r->print("<input type='checkbox' name='filelink"."' ".
		      "value='$filelink' onClick='".
		      "javascript:queue(\"form$fnum\")' ");
	    if ($hash{'store_'.$filelink}) {
		$r->print("checked");
	    }
	    $r->print(" />\n");
	    $r->print("</form></td><td nowrap='nowrap' valign='top'>");
	    $hash{"pre_${fnum}_link"}=$filelink;
	    $hash{"pre_${fnum}_title"}=$title;
	    if (!$hash{"pre_${fnum}_title"}) {
	        $hash{"pre_${fnum}_title"} = 'Not_retrieved';
	    }
  	    $fnum++;
	}
# Form to open or close sequences
	if ($filelink=~/\.(page|sequence)$/) {
	    my $curdir = $startdir.$filecom[0].'/';
	    &begin_form($r,$curdir);
	    $indent--;
	}
# General indentation
	if ($indent > 0 and $indent < 11) {
	    $r->print("<img alt=\"\" src='",$iconpath,"whitespace",$indent,
		      ".gif' class='LC_icon' />\n");
	} elsif ($indent >0) {
	    my $ten = int($indent/10.);
	    my $rem = $indent%10.0;
	    my $count = 0;
	    while ($count < $ten) {
		$r->print("<img alt=\"\" src=".$iconpath.
			  "whitespace10.gif class='LC_icon' />\n");
	    $count++;
	    }
	    $r->print("<img alt=\"\" src=",$iconpath,"whitespace",$rem,
		      ".gif class='LC_icon' />\n") if $rem > 0;
	}
# Sequence open/close icon
	if ($filelink=~/\.(page|sequence)$/) {
	    my $curdir = $startdir.$filecom[0].'/';
	    my $anchor = $curdir;
	    $anchor =~ s/\W//g;
	    $r->print ('<input type="hidden" name="acts" value="" />');
	    $r->print ('<a name="'.$anchor.'"></a><input src="'.$iconpath.
		       'folder_pointer_'.$diropen.'.gif"');
	    $r->print (' name="'.$msg.'" type="image" class="LC_indexer_icon" />'.
		       "\n");
	}
# Filetype icons
	$r->print("<img alt=\"\" src='$iconname' class='LC_icon' />\n");
	my $quotable_filelink = &Apache::loncommon::escape_single($filelink);

	$r->print (" <a href=\"javascript:openWindow('".$quotable_filelink.
		   "?inhibitmenu=yes','previewfile','450','500','no','yes','yes');\"".
		   " target=\"_self\">$listname</a> ");
	$quotable_filelink = &Apache::loncommon::escape_single($filelink.'.meta');
	&Apache::loncommon::inhibit_menu_check(\$quotable_filelink);
	$r->print (" (<a href=\"javascript:openWindow('".$quotable_filelink.
		   "?inhibitmenu=yes','metadatafile','500','550','no','yes','no');\" ".
		   " target=\"_self\">metadata</a>) ");
# Close form to open/close sequence
	if ($filelink=~/\.(page|sequence)$/) {
	    $r->print('</form>');
	}
	$r->print("</td>\n");
	if ($hash{'display_attrs_0'} == 1) {
	    $r->print('<td> '.($title eq '' ? '&nbsp;' : $title).
		      ' </td>'."\n");
	}
	$r->print('<td align=right> ',
		  $filecom[8]," </td>\n") 
	    if $hash{'display_attrs_1'} == 1;
	$r->print('<td> '.
		  (localtime($filecom[9]))." </td>\n") 
	    if $hash{'display_attrs_2'} == 1;
	$r->print('<td> '.
		  (localtime($filecom[10]))." </td>\n") 
	    if $hash{'display_attrs_3'} == 1;

	if ($hash{'display_attrs_4'} == 1) {
	    my $author = &Apache::lonnet::metadata($filelink,'author');
	    $r->print('<td> '.($author eq '' ? '&nbsp;' : $author).
		      " </td>\n");
	}
	if ($hash{'display_attrs_5'} == 1) {
	    my $keywords = &Apache::lonnet::metadata($filelink,'keywords');
	    # $keywords = '&nbsp;' if (!$keywords);
	    $r->print('<td> '.($keywords eq '' ? '&nbsp;' : $keywords).
		      " </td>\n");
	}
#'

	if ($hash{'display_attrs_6'} == 1) {
	    my $lang = &Apache::lonnet::metadata($filelink,'language');
	    $lang = &Apache::loncommon::languagedescription($lang);
	    $r->print('<td> '.($lang eq '' ? '&nbsp;' : $lang).
		      " </td>\n");
	}
	if ($hash{'display_attrs_8'} == 1) {
# statistics
	    &dynmetaread($filelink);
	    $r->print("<td>");
	    &dynmetaprint($r,$filelink,'count');
	    &dynmetaprint($r,$filelink,'course');
	    &dynmetaprint($r,$filelink,'stdno');
	    &dynmetaprint($r,$filelink,'avetries');
	    &dynmetaprint($r,$filelink,'difficulty');
	    &dynmetaprint($r,$filelink,'disc');
	    &dynmetaprint($r,$filelink,'clear');
	    &dynmetaprint($r,$filelink,'technical');
	    &dynmetaprint($r,$filelink,'correct');
	    &dynmetaprint($r,$filelink,'helpful');
	    &dynmetaprint($r,$filelink,'depth');
	    $r->print("&nbsp;</td>\n");

	}
	if ($hash{'display_attrs_10'} == 1) {
	    my $source = &Apache::lonnet::metadata($filelink,'sourceavail');
	    if($source eq 'open') {
		my $sourcelink = &Apache::lonsource::make_link($filelink,$listname);
		my $quotable_sourcelink = &Apache::loncommon::escape_single($sourcelink);
		&Apache::loncommon::inhibit_menu_check(\$quotable_sourcelink);
		$r->print('<td>'."<a href=\"javascript:openWindow('"
			  .$quotable_sourcelink.
			  "', 'previewsource', '700', '700', 'no', 'yes','yes');\"".
			  " target=\"_self\">Yes</a> "."</td>\n");
	    } else { #A cuddled else. :P
		$r->print("<td>&nbsp;</td>\n");
	    }
	}
	if ($hash{'display_attrs_11'} == 1) {
# links
	   &dynmetaread($filelink);
	   $r->print('<td>');
	   &coursecontext($r,$filelink);
	   &dynmetaprint($r,$filelink,'goto_list');
	   &dynmetaprint($r,$filelink,'comefrom_list');
	   &dynmetaprint($r,$filelink,'sequsage_list');
	   &dynmetaprint($r,$filelink,'dependencies');
           &dynmetaprint($r,$filelink,'course_list');
	   $r->print('</td>');
        }
        if ($hash{'display_attrs_7'} == 1) {
# Show resource
	   my $output=&showpreview($filelink);
           $r->print('<td> '.($output eq '' ? '&nbsp;':$output).
		      " </td>\n");
        }
	$r->print("</tr>\n");
    }

# -- display directory
    if ($fnptr == $dirptr) {
	my $curdir = $startdir.$filecom[0].'/';
	my $anchor = $curdir;
	$anchor =~ s/\W//g;
	$r->print("<tr bgcolor=\"$fileclr\">$extrafield<td valign=$valign>");
	&begin_form ($r,$curdir);
	my $indentm1 = $indent-1;
	if ($indentm1 < 11 and $indentm1 > 0) {
	    $r->print("<img alt=\"\" src=",$iconpath,"whitespace",$indentm1,
		      ".gif class='LC_icon' />\n");
	} else {
	    my $ten = int($indentm1/10.);
	    my $rem = $indentm1%10.0;
	    my $count = 0;
	    while ($count < $ten) {
		$r->print ("<img alt=\"\" src=",$iconpath
			   ,"whitespace10.gif class='LC_icon' />\n");
		$count++;
	    }
	    $r->print ("<img alt=\"\" src=",$iconpath,"whitespace",$rem,
		       ".gif class='LC_icon' />\n") if $rem > 0;
	}
	$r->print ('<input type="hidden" name="acts" value="" />');
	$r->print ('<a name="'.$anchor.'"></a><input src="'.$iconpath.
		   'folder_pointer_'.$diropen.'.gif"');
	$r->print (' name="'.$msg.'" type="image" class="LC_indexer_icon" />'.
		   "\n");
	my $quotable_curdir = &Apache::loncommon::escape_single($curdir);
	$r->print ('<a href="javascript:gothere(\''
		   .$quotable_curdir.'\')">'
		   .'<img alt="'.&mt('Open Folder').'"src="'.
		   $iconpath.'folder_'.$diropen.'.gif" class="LC_icon" /></a>'.
		   "\n");
	$r->print ("$listname</form></td>\n");
# Attributes
	my $filelink = $startdir.$filecom[0].'/default';

	if ($hash{'display_attrs_0'} == 1) {
	    my $title = &Apache::lonnet::gettitle($filelink);
	    $r->print('<td> '.($title eq '' ? '&nbsp;' : $title).
		      ' </td>'."\n");
	}
	$r->print('<td align=right> ',
		  $filecom[8]," </td>\n") 
	    if $hash{'display_attrs_1'} == 1;
	$r->print('<td> '.
		  (localtime($filecom[9]))." </td>\n") 
	    if $hash{'display_attrs_2'} == 1;
	$r->print('<td> '.
		  (localtime($filecom[10]))." </td>\n") 
	    if $hash{'display_attrs_3'} == 1;

	if ($hash{'display_attrs_4'} == 1) {
	    my $author = &Apache::lonnet::metadata($filelink,'author');
	    $r->print('<td> '.($author eq '' ? '&nbsp;' : $author).
		      " </td>\n");
	}
	if ($hash{'display_attrs_5'} == 1) {
	    my $keywords = &Apache::lonnet::metadata($filelink,'keywords');
	    # $keywords = '&nbsp;' if (!$keywords);
	    $r->print('<td> '.($keywords eq '' ? '&nbsp;' : $keywords).
		      " </td>\n");
	}
	if ($hash{'display_attrs_6'} == 1) {
	    my $lang = &Apache::lonnet::metadata($filelink,'language');
	    $lang = &Apache::loncommon::languagedescription($lang);
	    $r->print('<td> '.($lang eq '' ? '&nbsp;' : $lang).
		      " </td>\n");
	}
	if ($hash{'display_attrs_8'} == 1) {
	   $r->print('<td>&nbsp;</td>');
	}
 	if ($hash{'display_attrs_10'} == 1) {
	   $r->print('<td>&nbsp;</td>');
	}
	if ($hash{'display_attrs_11'} == 1) {
	   $r->print('<td>&nbsp;</td>');
	}
	if ($hash{'display_attrs_7'} == 1) {
	   $r->print('<td>&nbsp;</td>');
        }
	$r->print('</tr>');
    }

}

sub coursecontext {
    my ($r,$filelink)=@_;
    my $filesymb=&Apache::lonnet::symbread($filelink);
    if ($filesymb) {
	my ($map,$index,$resource)=&Apache::lonnet::decode_symb($filesymb);
	$r->print(&mt('Already in this course:<br />[_1] in folder/map [_2].<br />',
	      &Apache::lonnet::gettitle($resource),
	      &Apache::lonnet::gettitle($map)));
    }
}

sub showpreview {
    my ($filelink)=@_;
    if ($filelink=~m-^(/ext/|http://)-) {
	return &mt('External Resource, preview not enabled');
    }
    my ($curfext)=($filelink=~/\.(\w+)$/);
    my $output='';
    my $embstyle=&Apache::loncommon::fileembstyle($curfext);
    if ($embstyle eq 'ssi') {
       my $cache=$Apache::lonnet::perlvar{'lonDocRoot'}.$filelink.
                    '.tmp';
       if ((!$env{'form.updatedisplay'}) &&
                    (-e $cache)) {
          open(FH,$cache);
          $output=join("\n",<FH>);
          close(FH);
       } else {
# In update display mode, remove old cache. This is done to retroactively
# clean up course context renderings.
	  if (-e $cache) {
	       unlink($cache);
	  }
          $output=&Apache::lonnet::ssi_body($filelink);
# Is access denied? Don't render, don't store
          if ($output=~/LONCAPAACCESSCONTROLERRORSCREEN/s) {
             $output='';
# Was this rendered in course content? Don't store
          } elsif (!&Apache::lonnet::symbread($filelink)) {
             open(FH,">$cache");
             print FH $output;
             close(FH);
          }
       }
       $output='<font size="-2">'.$output.'</font>';
    } elsif ($embstyle eq 'img') {
       $output='<img alt="'.&mt('Preview').'" src="'.$filelink.'" />';
    } elsif ($filelink=~m{^/res/($match_domain)/($match_username)/}) {
       $output='<img  alt="'.&mt('Preview').'" src="http://'.
                 &Apache::lonnet::hostname(&Apache::lonnet::homeserver($2,$1)).
                 '/cgi-bin/thumbnail.gif?url='.$filelink.'" />';
    }
    return $output;
}

sub dynmetaprint {
    my ($r,$filelink,$item)=@_;
    if ($dynhash{$filelink}->{$item}) {
	$r->print("\n<br />".$fieldnames{$item}.': '.
		  &Apache::lonmeta::prettyprint($item,
						$dynhash{$filelink}->{$item},
		  (($env{'form.catalogmode'} ne 'import')?'preview':''),
		  '',
		  (($env{'form.catalogmode'} eq 'import')?'document.forms.fileattr':''),1));
    }
}

# ------------------- prints the beginning of a form for directory or file link
sub begin_form {
    my ($r,$uri) = @_;
    my $anchor = $uri;
    $anchor =~ s/\W//g;
    $uri=&Apache::loncommon::escape_single($uri);
    $r->print ('<form method="post" name="dirpath'.$dnum.'" action="'.$uri.
	       '#'.$anchor.
	       '" onSubmit="return rep_dirpath(\''.$dnum.'\''.
	       ',document.forms.fileattr.acts.value)" '.
	       'enctype="application/x-www-form-urlencoded">'."\n");
    $r->print ('<input type="hidden" name="openuri" value="'.$uri.'" />'.
	       "\n");
    $r->print ('<input type="hidden" name="dirPointer" value="on" />'."\n");
    $r->print(&Apache::loncommon::inhibit_menu_check('input'));
    $dnum++;
}

# --------- settings whenever the user causes the indexer window to be launched
sub start_fresh_session {
    my ($hash) = @_;
    delete $hash->{'form.catalogmode'};
    delete $hash->{'form.mode'};
    delete $hash->{'form.form'};
    delete $hash->{'form.element'};
    delete $hash->{'form.omit'};
    delete $hash->{'form.only'};
    foreach (keys %{$hash}) {
        delete $hash->{$_} if (/^(pre_|store)/);
    }
}

# ------------------------------------------------------------------- setvalues
sub setvalues {
    # setvalues is used in registerurl to synchronize the database
    # hash and environment hashes
    my ($H1,$h1key,$H2,$h2key) =@_;
    #
    if (exists $H2->{$h2key}) {
	$H1->{$h1key} = $H2->{$h2key};
    } elsif (exists $H1->{$h1key}) {
	$H2->{$h2key} = $H1->{$h1key};
    } 
}

1;

sub cleanup {
    if (tied(%hash)){
	&Apache::lonnet::logthis('Cleanup indexer: hash');
    }
    return OK;
}





=head1 NAME

Apache::lonindexer - mod_perl module for cross server filesystem browsing

=head1 SYNOPSIS

Invoked by /etc/httpd/conf/srm.conf:

 <LocationMatch "^/res.*/$">
 SetHandler perl-script
 PerlHandler Apache::lonindexer
 </LocationMatch>

=head1 INTRODUCTION

This module enables a scheme of browsing across a cross server.

This is part of the LearningOnline Network with CAPA project
described at http://www.lon-capa.org.

=head1 BEGIN SUBROUTINE

This routine is only run once after compilation.

=over 4

=item *

Initializes %language hash table.

=back

=head1 HANDLER SUBROUTINE

This routine is called by Apache and mod_perl.

=over 4

=item *

read in machine configuration variables

=item *

see if called from an interactive mode

=item *

refresh environment with user database values (in %hash)

=item *

define extra fields and buttons in case of special mode

=item *

set catalogmodefunctions to have extra needed javascript functionality

=item *

print header

=item *

evaluate actions from previous page (both cumulatively and chronologically)

=item *

output title

=item *

get state of file attributes to be showing

=item *

output state of file attributes to be showing

=item *

output starting row to the indexed file/directory hierarchy

=item *

read in what directories have previously been set to "open"

=item *

if not at top level, provide an uplink arrow

=item *

recursively go through all the directories and output as appropriate

=item *

information useful for group import

=item *

end the tables

=item *

end the output and return

=back

=head1 OTHER SUBROUTINES

=over 4

=item *

scanDir - recursive scan of a directory

=item *

get_list - get complete matched list based on the uri (returns an array)

=item *

match_ext - filters out files based on extensions (returns an array)

=item *

display_line - displays one line in appropriate table format

=item *

begin_form - prints the beginning of a form for directory or file link

=item *

start_fresh_session - settings whenever the user causes the indexer window
to be launched

=back

=cut