--- rat/lonpageflip.pm	2005/08/02 21:15:52	1.55
+++ rat/lonpageflip.pm	2013/11/28 02:23:25	1.83
@@ -2,7 +2,7 @@
 #
 # Page flip handler
 #
-# $Id: lonpageflip.pm,v 1.55 2005/08/02 21:15:52 albertel Exp $
+# $Id: lonpageflip.pm,v 1.83 2013/11/28 02:23:25 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -27,11 +27,15 @@
 # http://www.lon-capa.org/
 #
 
+
+
 package Apache::lonpageflip;
 
 use strict;
+use LONCAPA;
 use Apache::Constants qw(:common :http REDIRECT);
 use Apache::lonnet;
+use Apache::loncommon();
 use HTML::TokeParser;
 use GDBM_File;
 
@@ -46,6 +50,7 @@ sub cleanup {
 	    &Apache::lonnet::logthis('Failed cleanup pageflip: hash');
         }
     }
+    return OK;
 }
 
 sub addrid {
@@ -73,13 +78,50 @@ sub fullmove {
 
 sub hash_src {
     my ($id)=@_;
+    my ($mapid,$resid)=split(/\./,$id);
+    my $symb=&Apache::lonnet::encode_symb($hash{'map_id_'.$mapid},
+					  $resid,$hash{'src_'.$id});
     if ($hash{'encrypted_'.$id}) {
-	return &Apache::lonenc::encrypted($hash{'src_'.$id});
+	return (&Apache::lonenc::encrypted($hash{'src_'.$id}),
+		&Apache::lonenc::encrypted($symb));
     }
-    return $hash{'src_'.$id};
+    return ($hash{'src_'.$id},$symb);
 }
 
 sub move {
+    my ($next,$endupmap,$direction) = @_;
+    my $safecount=0;
+    my $allowed=0;
+    do {
+	($next,$endupmap)=&get_next_possible_move($next,$endupmap,$direction);
+
+	my $url = $hash{'src_'.$next};
+	my ($mapid,$resid)=split(/\./,$next);
+	my $symb = &Apache::lonnet::encode_symb($hash{'map_id_'.$mapid},
+						$resid,$url);
+	if ($url eq '' || $symb eq '') {
+	    $allowed = 0;
+	} else {
+	    my $priv = &Apache::lonnet::allowed('bre',$url,$symb);
+	    $allowed = (($priv eq 'F') || ($priv eq '2'));
+	}
+	$safecount++;
+    } while (   ($next)
+	     && ($next!~/\,/)
+	     && (
+		    (!$hash{'src_'.$next})
+		 || (
+		        (!$env{'request.role.adv'})
+		     &&  $hash{'randomout_'.$next}
+		    )
+		 || (!$allowed)
+		)
+	     && ($safecount<10000));
+
+    return ($next,$endupmap);
+}
+
+sub get_next_possible_move {
     my ($rid,$mapurl,$direction)=@_;
     my $startoutrid=$rid;
 
@@ -92,25 +134,27 @@ sub move {
                   while ($hash{'type_'.$rid} eq 'finish') {
 	             $rid=$hash{'ids_'.$hash{'map_id_'.(split(/\./,$rid))[0]}};
                   }
-                  map {
-                      my $thiscond=
-      &Apache::lonnet::directcondval($hash{'condid_'.$hash{'undercond_'.$_}});
-                      if ($thiscond>=$mincond) {
+		  foreach my $id (split(/\,/,$hash{'to_'.$rid})) {
+		     my $condition= $hash{'conditions_'.$hash{'goesto_'.$id}};
+		     my $rescond  = &Apache::lonnet::docondval($condition);
+		     my $linkcond = &Apache::lonnet::directcondval($hash{'condid_'.$hash{'undercond_'.$id}});
+		     my $thiscond = ($rescond<$linkcond)?$rescond:$linkcond;
+		     if ($thiscond>=$mincond) {
 		          if ($posnext) {
-		             $posnext.=','.$_.':'.$thiscond;
+		             $posnext.=','.$id.':'.$thiscond;
                           } else {
-                             $posnext=$_.':'.$thiscond;
+                             $posnext=$id.':'.$thiscond;
 		          }
                           if ($thiscond>$mincond) { $mincond=$thiscond; }
 	              }
-                  } split(/\,/,$hash{'to_'.$rid});
-                  map {
-                      my ($linkid,$condval)=split(/\:/,$_);
+                  } 
+		  foreach my $id (split(/\,/,$posnext))  {
+                      my ($linkid,$condval)=split(/\:/,$id);
                       if ($condval>=$mincond) {
 		          $next=&addrid($next,$hash{'goesto_'.$linkid},
                                 $hash{'condid_'.$hash{'undercond_'.$linkid}});
                       }
-                  } split(/\,/,$posnext);
+                  }
                   if ($hash{'is_map_'.$next}) {
 # This jumps to the beginning of a new map (going down level)
                       if (
@@ -126,31 +170,33 @@ sub move {
                     ((split(/\./,$startoutrid))[0]!=(split(/\./,$next))[0]) {
 # This comes up from a map (coming up one level);
 		      $mapurl=$hash{'map_id_'.(split(/\./,$next))[0]};
-                  }
+		  }
               } elsif ($direction eq 'back') {
 # ------------------------------------------------------------------- Backwards
                  while ($hash{'type_'.$rid} eq 'start') {
 	             $rid=$hash{'ids_'.$hash{'map_id_'.(split(/\./,$rid))[0]}};
 		 }
-                  map {
-                      my $thiscond=
-      &Apache::lonnet::directcondval($hash{'condid_'.$hash{'undercond_'.$_}});
-                      if ($thiscond>=$mincond) {
-		          if ($posnext) {
-		             $posnext.=','.$_.':'.$thiscond;
-                          } else {
-                             $posnext=$_.':'.$thiscond;
-		          }
-                          if ($thiscond>$mincond) { $mincond=$thiscond; }
-	              }
-                  } split(/\,/,$hash{'from_'.$rid});
-                  map {
-                      my ($linkid,$condval)=split(/\:/,$_);
-                      if ($condval>=$mincond) {
-		          $next=&addrid($next,$hash{'comesfrom_'.$linkid},
-                                $hash{'condid_'.$hash{'undercond_'.$linkid}});
-                      }
-                  } split(/\,/,$posnext);
+		 foreach my $id (split(/\,/,$hash{'from_'.$rid})) {
+		     my $condition= $hash{'conditions_'.$hash{'comesfrom_'.$id}};
+		     my $rescond  = &Apache::lonnet::docondval($condition);
+		     my $linkcond = &Apache::lonnet::directcondval($hash{'condid_'.$hash{'undercond_'.$id}});
+		     my $thiscond = ($rescond<$linkcond)?$rescond:$linkcond;
+		     if ($thiscond>=$mincond) {
+			 if ($posnext) {
+		             $posnext.=','.$id.':'.$thiscond;
+			 } else {
+                             $posnext=$id.':'.$thiscond;
+			 }
+			 if ($thiscond>$mincond) { $mincond=$thiscond; }
+		     }
+		 } 
+		 foreach my $id (split(/\,/,$posnext)) {
+		     my ($linkid,$condval)=split(/\:/,$id);
+		     if ($condval>=$mincond) {
+			 $next=&addrid($next,$hash{'comesfrom_'.$linkid},
+				       $hash{'condid_'.$hash{'undercond_'.$linkid}});
+		     }
+		 }
                   if ($hash{'is_map_'.$next}) {
 # This jumps to the end of a new map (going down one level)
                       if (
@@ -171,28 +217,35 @@ sub move {
               return ($next,$mapurl);
 }
 
-sub navlaunch {
-    my ($r)=@_;
-    &Apache::loncommon::content_type($r,'text/html');
-    &Apache::loncommon::no_cache($r);
-    $r->send_http_header;
-    my $html=&Apache::lonxml::xmlbegin();
-    $r->print("$html<head>\n");
-    $r->print('</head>'.
-	      &Apache::loncommon::bodytag('Launched'));   
-    $r->print(<<ENDNAV);
-    <p><a href="/adm/flip?postdata=firstres%3a">Goto first resource</a></p>
-    <script type="text/javascript">
-	function collapse() {
-	    menu=window.open("/adm/navmaps?collapseExternal","loncapanav",
-			     "height=600,width=400,scrollbars=1");
-	    this.document.location='/adm/navmaps?turningOffExternal';
+sub first_accessible_resource {
+    my $furl;
+    if (tie(%hash,'GDBM_File',$env{'request.course.fn'}.'.db',
+	    &GDBM_READER(),0640)) {
+	$furl=$hash{'first_url'};
+	my %args;
+	my ($url,$args) = split(/\?/,$furl);
+	foreach my $pair (split(/\&/,$args)) {
+	    my ($name,$value) = split(/=/,$pair);
+	    $args{&unescape($name)} = &unescape($value);
+	}
+        if (!&Apache::lonnet::allowed('bre',$url,$args{'symb'})) {
+# Wow, we cannot see this ... move forward to the next one that we can see
+	    my ($newrid,$newmap)=&move($hash{'first_rid'},$hash{'first_mapurl'},'forward');
+# Build the new URL
+	    my ($newmapid,$newresid)=split(/\./,$newrid);
+	    my $symb=&Apache::lonnet::encode_symb($newmap,$newresid,$hash{'src_'.$newrid});
+	    $furl=&add_get_param($hash{'src_'.$newrid},{ 'symb' => $symb });
+	    if ($hash{'encrypted_'.$newrid}) {
+		$furl=&Apache::lonenc::encrypted($furl);
+	    }
 	}
-    </script>
-    <p><a href="javascript:collapse();">Collapse external navigation window</a></p>
-ENDNAV
-    $r->print(&Apache::loncommon::endbodytag().'</html>');
+	untie(%hash);
+	return $furl;
+    } else {
+	return '/adm/navmaps';
+    }
 }
+
 # ================================================================ Main Handler
 
 sub handler {
@@ -209,7 +262,7 @@ sub handler {
   my %cachehash=(); 
   my $multichoice=0;
   my %multichoicehash=();
-  my $redirecturl='';
+  my ($redirecturl,$redirectsymb);
   my $next='';
   my @possibilities=();
    &Apache::loncommon::get_unprocessed_cgi($ENV{'QUERY_STRING'},['postdata']);
@@ -222,19 +275,14 @@ sub handler {
       }
       $currenturl=~s/\.\d+\.(\w+)$/\.$1/;
       if ($direction eq 'firstres') {
-	  my $furl;
-	  if (tie(my %bighash,'GDBM_File',$env{'request.course.fn'}.'.db',
-		  &GDBM_READER(),0640)) {
-	      $furl=$bighash{'first_url'};
-	      untie(%bighash);
-	  }
+	  my $furl=&first_accessible_resource();
 	  &Apache::loncommon::content_type($r,'text/html');
 	  $r->header_out(Location => 
-			 'http://'.$ENV{'HTTP_HOST'}.$furl);
+			 &Apache::lonnet::absolute_url().$furl);
 	     
 	  return REDIRECT;
       }
-      if ($direction eq 'return' || $direction eq 'navlaunch') {
+      if ($direction eq 'return') {
 # -------------------------------------------------------- Return to last known
          my $last;
          if (tie(%hash,'GDBM_File',$env{'request.course.fn'}.'_symb.db',
@@ -252,24 +300,19 @@ sub handler {
 		if ($hash{'encrypted_'.$id}) { $newloc=&Apache::lonenc::encrypted($newloc); }
 			      
 	    } else {
-		$newloc='/adm/noidea.html';
+		$newloc='/adm/navmaps';
 	    }
             untie %hash;
          } else {
-	    $newloc='/adm/noidea.html';
+	    $newloc='/adm/navmaps';
          }  
-	 if ($newloc eq '/adm/noidea.html' && $direction eq 'navlaunch') {
-	     &navlaunch($r);
-	     return OK;
-	 } else {
 	     &Apache::loncommon::content_type($r,'text/html');
 	     $r->header_out(Location => 
-			    'http://'.$ENV{'HTTP_HOST'}.$newloc);
+			    &Apache::lonnet::absolute_url().$newloc);
 	     
 	     return REDIRECT;
-	 }
       }
-      $currenturl=~s/^http\:\/\///;
+      $currenturl=~s/^https?\:\/\///;
       $currenturl=~s/^[^\/]+//;
 #
 # Is the current URL on the map? If not, start with last known URL
@@ -284,15 +327,11 @@ sub handler {
          if ($last) {
 	     $currenturl=&Apache::lonnet::clutter((&Apache::lonnet::decode_symb($last))[2]);
 	 } else {
-	     if ($direction eq 'return') {
 		 &Apache::loncommon::content_type($r,'text/html');
 		 $r->header_out(Location => 
-				'http://'.$ENV{'HTTP_HOST'}.'/adm/noidea.html');
+				&Apache::lonnet::absolute_url().
+				'/adm/noidea.html');
 		 return REDIRECT;
-	     } else {
-		 &navlaunch($r);
-		 return OK;
-	     }
          }
       }
 # ------------------------------------------- Do we have any idea where we are?
@@ -314,41 +353,33 @@ sub handler {
               my $endupmap;
               ($next,$endupmap)=&move($rid,$startoutmap,$direction);
 # -------------------------------------- Do we have one and only one empty URL?
-              my $safecount=0;
-              while (($next) && ($next!~/\,/) && 
-                     ((!$hash{'src_'.$next}) || 
-		      ((!$env{'request.role.adv'}) && $hash{'randomout_'.$next}))
-                     && ($safecount<10000)) {
-                  ($next,$endupmap)=&move($next,$endupmap,$direction);
-                  $safecount++;
-              }
 # We are now at at least one non-empty URL
 # ----------------------------------------------------- Check out possibilities
               if ($next) {
                   @possibilities=split(/\,/,$next);
                   if ($#possibilities==0) {
 # ---------------------------------------------- Only one possibility, redirect
-	              $redirecturl=&hash_src($next);
+	              ($redirecturl,$redirectsymb)=&hash_src($next);
                       $cachehash{$endupmap}{$redirecturl}=
 			  [$redirecturl,(split(/\./,$next))[1]];
                   } else {
 # ------------------------ There are multiple possibilities for a next resource
                       $multichoice=1;
-                      map {
-			  $multichoicehash{'src_'.$_}=$hash{'src_'.$_};
-                          $multichoicehash{'title_'.$_}=$hash{'title_'.$_};
-                          $multichoicehash{'type_'.$_}=$hash{'type_'.$_};
-                          (my $first, my $second) = $_ =~ /(\d+).(\d+)/;
-                          my $symbSrc = Apache::lonnet::declutter($hash{'src_'.$_});
-                          $multichoicehash{'symb_'.$_} = 
+		      foreach my $id (@possibilities) {
+			  $multichoicehash{'src_'.$id}=$hash{'src_'.$id};
+                          $multichoicehash{'title_'.$id}=$hash{'title_'.$id};
+                          $multichoicehash{'type_'.$id}=$hash{'type_'.$id};
+                          (my $first, my $second) = $id =~ /(\d+).(\d+)/;
+                          my $symbSrc = Apache::lonnet::declutter($hash{'src_'.$id});
+                          $multichoicehash{'symb_'.$id} = 
                               Apache::lonnet::declutter($hash{'map_id_'.$first}.'___'.
                                                         $second.'___'.$symbSrc);
                                                          
-                          my ($choicemap,$choiceres)=split(/\./,$_);
+                          my ($choicemap,$choiceres)=split(/\./,$id);
 			  my $map=&Apache::lonnet::declutter($hash{'src_'.$choicemap});
-			  my $url=$multichoicehash{'src_'.$_};
+			  my $url=$multichoicehash{'src_'.$id};
                           $cachehash{$map}{$url}=[$url,$choiceres];
-                      } @possibilities;
+                      }
                   }
 	      } else {
 # -------------------------------------------------------------- No place to go
@@ -382,61 +413,73 @@ sub handler {
 	                if (($what[0] ne 'con_lost') && 
                             ($what[0]!~/^error\:/)) {
 	                   $redirecturl='/adm/email?critical=display';
+			   $redirectsymb='';
                         }
                      }
-                     &Apache::lonnet::appenv('user.criticalcheck.time'=>time);
+                     &Apache::lonnet::appenv({'user.criticalcheck.time'=>time});
 		  }
 
 		  &Apache::loncommon::content_type($r,'text/html');
-                  $r->header_out(Location => 
-                                'http://'.$ENV{'HTTP_HOST'}.$redirecturl);
+		  my $url=&Apache::lonnet::absolute_url().$redirecturl;
+		  $url = &add_get_param($url, { 'symb' => $redirectsymb});
+                  $r->header_out(Location => $url);
                   return REDIRECT;
 	      } else {
 # --------------------------------------------------------- There was a problem
                   &Apache::loncommon::content_type($r,'text/html');
                   $r->send_http_header;
+		  my %lt=&Apache::lonlocal::texthash('title' => 'End of Sequence',
+						     'explain' =>
+						     'You have reached the end of the sequence of materials.',
+						     'back' => 'Go Back',
+						     'nav' => 'Course Contents',
+						     'wherenext' =>
+						     'There are several possibilities of where to go next',
+						     'pick' =>
+						     'Please click on the the resource you intend to access',
+						     'titleheader' => 'Title',
+						     'type' => 'Type');
+                  if (&Apache::loncommon::course_type() eq 'Community') {
+                      $lt{'nav'} = &mt('Community Contents');
+                  }
                   if ($#possibilities>0) {
-		      my $bodytag=
-                             &Apache::loncommon::bodytag('Multiple Resources');
+		      my $start_page=
+			  &Apache::loncommon::start_page('Multiple Resources');
                      $r->print(<<ENDSTART);
-<head><title>Choose Next Location</title></head>
-$bodytag
-<h3>There are several possibilities of where to go next</h3>
+$start_page
+<h3>$lt{'wherenext'}</h3>
 <p>
-Please click on the the resource you intend to access:
+$lt{'pick'}:
 <p>
-<table border=2>
-<tr><th>Title</th><th>Type</th></tr>
+<table border="2">
+<tr><th>$lt{'titleheader'}</th><th>$lt{'type'}</th></tr>
 ENDSTART
-                     foreach (@possibilities) {
+                     foreach my $id (@possibilities) {
                         $r->print(
                               '<tr><td><a href="'.
-                              $multichoicehash{'src_'.$_}.'?symb=' .
-                                  Apache::lonnet::escape($multichoicehash{'symb_'.$_}).'">'.
-                              $multichoicehash{'title_'.$_}.
-                              '</a></td><td>'.$multichoicehash{'type_'.$_}.
+				  &add_get_param($multichoicehash{'src_'.$id},
+						 {'symb' =>
+						      $multichoicehash{'symb_'.$id},
+						  }).'">'.
+                              $multichoicehash{'title_'.$id}.
+                              '</a></td><td>'.$multichoicehash{'type_'.$id}.
 			      '</td></tr>');
                      }
-                     $r->print('</table></body></html>');
-		     return OK;
+                     $r->print('</table>');
                   } else {
-		      my $bodytag=&Apache::loncommon::bodytag('No Resource');
-                     $r->print(<<ENDNONE);
-<head><title>No Resource</title></head>
-$bodytag
-<h3>Next resource could not be identified.</h3>
-<p>You probably are at the <b>beginning</b> or the <b>end</b> of the 
-course.</p>
-<ul>
-<li><a href="/adm/flip?postdata=return:">Go Back</a></li>
-<li><a href="/adm/navmaps">Navigate Course Content</a></li>
-</ul>
-</body>
-</html>
-ENDNONE
-                     return OK;
-	         }
-	     }
+                      $r->print(
+                          &Apache::loncommon::start_page('No Resource')
+                         .'<h2>'.$lt{'title'}.'</h2>'
+                         .'<p>'.$lt{'explain'}.'</p>');
+                  }
+                  $r->print(
+                      &Apache::lonhtmlcommon::actionbox(
+                          ['<a href="/adm/flip?postdata=return:">'.$lt{'back'}.'</a></li>',
+                           '<a href="/adm/navmaps">'.$lt{'nav'}.'</a></li>'
+                          ])
+                     .&Apache::loncommon::end_page());
+                  return OK;
+	      }
 	  } else {
 # ------------------------------------------------- Problem, could not tie hash
               $env{'user.error.msg'}="/adm/flip:bre:0:1:Course Data Missing";
@@ -444,10 +487,8 @@ ENDNONE
           }
       } else {
 # ---------------------------------------- No, could not determine where we are
-	  if ( &Apache::lonnet::mod_perl_version() == 2 ) {
-	      &Apache::lonnet::cleanenv();
-	  }
 	  $r->internal_redirect('/adm/ambiguous');
+          return OK;
       }
   } else {
 # -------------------------- Class was not initialized or page fliped strangely
@@ -459,6 +500,44 @@ ENDNONE
 1;
 __END__
 
+=pod
+
+=head1 NAME
+
+Apache::lonpageflip
+
+=head1 SYNOPSIS
+
+Deals with forward, backward, and other page flips.
+
+This is part of the LearningOnline Network with CAPA project
+described at http://www.lon-capa.org.
+
+=head1 OVERVIEW
+
+(empty)
+
+=head1 SUBROUTINES
+
+=over cleanup()
+
+=item addrid()
+
+=item fullmove()
+
+=item hash_src()
+
+=item move()
+
+=item get_next_possible_move()
+
+=item first_accessible_resource()
+
+=item handler()
+
+=back
+
+=cut