File:  [LON-CAPA] / rat / lonsequence.pm
Revision 1.11: download - view: text, annotated - select for diffs
Thu May 23 15:07:55 2002 UTC (21 years, 10 months ago) by www
Branches: MAIN
CVS tags: HEAD
Bug #175
If the beginning of a sequence is an empty resource, use "move" from
lonpageflip now to get to non-empty page.

# The LearningOnline Network with CAPA
#
# Sequence Handler
#
# $Id: lonsequence.pm,v 1.11 2002/05/23 15:07:55 www 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/
#
# (Handler to resolve ambiguous file locations
#
# (TeX Content Handler
#
# 05/29/00,05/30,10/11 Gerd Kortemeyer)
#
# 10/11,10/12 Gerd Kortemeyer)
#
# 10/16 Gerd Kortemeyer

package Apache::lonsequence;

use strict;
use Apache::lonnet;
use Apache::Constants qw(:common :http REDIRECT);
use GDBM_File;
use Apache::lonratedt;
use Apache::lonratsrv;
use Apache::lonpageflip;

# ----------------------------------------------------------- Could not resolve

sub getlost {
    my ($r,$errmsg)=@_;
    $r->content_type('text/html');
    $r->send_http_header;
    $r->print(
 '<head><title>Unknown Error</title></head><body bgcolor="#FFFFFF"><h1>'.
 'LON-CAPA</h1>Could not handle sequence resource reference.<p>'.$errmsg.
 '</body></html>');
}


# ----------------------------------------- Attempt to read from resource space

sub attemptread {
    my $fn=shift;
    &Apache::lonnet::repcopy($fn);
    if (-e $fn) {
	return &Apache::lonratedt::attemptread($fn);
    } else {
        return ();
    }
}

# ---------------------------------------------------------------- View Handler

sub viewmap {
    my ($r,$url)=@_;
    $r->print('<html>');
    if ($ENV{'form.forceselect'}) { $r->print(<<ENDSCRIPT);
<script>

function select_group() {
    window.location="/adm/groupsort?catalogmode=groupimport&mode=rat&acts="+document.forms.fileattr.acts.value;
}

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';
    }
}

</script>
ENDSCRIPT
    }
    $r->print('<body bgcolor="#FFFFFF">');
    if ($ENV{'form.forceselect'}) { $r->print(<<ENDSELECT);
<form name=fileattr><input type=hidden name=acts value=''>
<input type="button" name="close" value='CLOSE' onClick="self.close()">
<input type="button" name="groupimport" value='GROUP IMPORT'
onClick="javascript:select_group()">
</form>   
ENDSELECT
    }
    my $idx=0;
    foreach (&attemptread(&Apache::lonnet::filelocation('',$url))) {
	if (defined($_)) {
            $idx++;
            if ($ENV{'form.forceselect'}) { 
		$r->print('<form name="form'.$idx.'">');
            }
	    my ($title,$url)=split(/\:/,$_);
            $title=~s/\&colon\;/\:/g;
            $url=~s/\&colon\;/\:/g;
            unless ($title) { $title=(split(/\//,$url))[-1] };
            unless ($title) { $title='<i>Empty</i>'; }
            if ($url) {
		if ($ENV{'form.forceselect'}) {
		    $r->print(<<ENDCHECKBOX);
<input type='checkbox' name='filelink' 
value='$url' onClick='javascript:queue("form$idx")' >
<input type='hidden' name='title' value='$title'>
ENDCHECKBOX
                }
		$r->print('<a href="'.&Apache::lonratsrv::qtescape($url).'">');
            }
            $r->print(&Apache::lonratsrv::qtescape($title));
            if ($url) { $r->print('</a>'); }
            if ($ENV{'form.forceselect'}) {
		$r->print('</form>');
            } else {
		$r->print('<br>');
            }
        }
    }
    $r->print('</body></html>');
}

# ================================================================ Main Handler

sub handler {
   my $r=shift;

   if ($r->header_only) {
      $r->content_type('text/html');
      $r->send_http_header;
      return OK;
   }
 
   &Apache::loncommon::get_unprocessed_cgi($ENV{'QUERY_STRING'},
                                          ['forceselect']);

   my %hash;
   my %bighash;
   my $requrl=$r->uri;

# ------------------------------------------------------------ Tie symb db file
  my $disurl='';
  my $dismapid='';

  if (($ENV{'request.course.fn'}) && (!$ENV{'form.forceselect'})) {
       my $last;
       if (tie(%hash,'GDBM_File',$ENV{'request.course.fn'}.'_symb.db',
                    &GDBM_READER,0640)) {
	   $last=$hash{'last_direction'};
           untie(%hash);
       }
       my $direction='';
       my $prevmap='';
       if ($last) {
	  ($prevmap,$direction)=(split(/\_\_\_/,$last));
       }
# ------------------------------------------------------------- Tie big db file
       if (tie(%bighash,'GDBM_File',$ENV{'request.course.fn'}.'.db',
                    &GDBM_READER,0640)) {
	   my $disid='';

           if ($direction eq 'back') {
	       $disid=$bighash{'map_finish_'.$requrl};
           } else {
               $disid=$bighash{'map_start_'.$requrl};
           } 
           if ($disid) {
	       $disurl=$bighash{'src_'.$disid};
               $dismapid=(split(/\./,$disid))[1];
           }
# ------------------------- If this is an empty one, skip to next non-empty one
           if ((!$disurl) && ($disid)) {
	       $direction=($direction?$direction:'forward');
               ($disid,$requrl)=
                         &Apache::lonpageflip::fullmove($disid,
                           &Apache::lonnet::declutter($requrl),$direction);
               if ($disid) {
	           $disurl=$bighash{'src_'.$disid};
                   $dismapid=(split(/\./,$disid))[1];
               }
 	   }

# --------------------------------------- Untie hash, make sure to come by here
           untie(%bighash);
       }
   }

# now either disurl is set (going to first page), or we need another display

   if ($disurl) {
# -------------------------------------------------- Has first or last resource
      &Apache::lonnet::symblist($requrl,$disurl => $dismapid,
                   'last_known' => &Apache::lonnet::declutter($disurl)); 
      $r->content_type('text/html');
      $r->header_out(Location => 'http://'.$ENV{'HTTP_HOST'}.$disurl);
      return REDIRECT;
   } else {
       $r->content_type('text/html');
       $r->send_http_header;
       &viewmap($r,$requrl);
       return OK;
   }
}

1;
__END__








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