--- loncom/xml/londefdef.pm	2012/03/01 21:13:36	1.438
+++ loncom/xml/londefdef.pm	2024/07/03 22:44:22	1.456.2.7
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # Tags Default Definition Module 
 #
-# $Id: londefdef.pm,v 1.438 2012/03/01 21:13:36 droeschl Exp $
+# $Id: londefdef.pm,v 1.456.2.7 2024/07/03 22:44:22 raeburn Exp $
 # 
 #
 # Copyright Michigan State University Board of Trustees
@@ -92,6 +92,26 @@ sub start_m {
     my $inside = &Apache::lonxml::get_all_text_unbalanced("/m",$parser);
     if ($target eq 'web' || $target eq 'analyze') {
 	&Apache::lonxml::debug("M is starting with:$inside:");
+        if (!($inside =~ /^\s*\$.*\$\s*$/ || $inside =~ /^\s*\\[([].*\\[)\]]\s*$/)) {
+            # Non-math LaTeX will not be rendered correctly with MathJax
+            # and it should be avoided anyway.
+            # On top of that, MathJax will render math without $, but
+            # it will fail with tth. This is worth a warning.
+            # (even though some people might just use latex for printing)
+            &Apache::lonxml::warning(&mt('Missing $ in [_1].','<m>'));
+        } elsif (($env{'browser.type'} eq 'safari') && ($env{'form.editxmltext'}) &&
+                 (($env{'form.problemmode'} eq 'view') || ($env{'form.problemmode'} eq 'discard'))) {
+            my $delimiter;
+            if ($inside =~ /\$$/) {
+                $delimiter = '$';
+            } elsif ($inside =~ /\\([)\]])$/) {
+                $delimiter = $1;
+            }
+            if ($delimiter) {
+                &Apache::lonxml::warning(&mt('Insert a space between [_1] and [_2].',
+                                             $delimiter,'</m>'));
+            }
+        }
 	my $eval=&Apache::lonxml::get_param('eval',$parstack,$safeeval);
 	if ($eval eq 'on') {
 	    $inside=&Apache::run::evaluate($inside,$safeeval,$$parstack[-1]);
@@ -572,7 +592,7 @@ sub start_body {
     if ($env{'request.state'} eq 'construct') {
         my $url=&Apache::lonnet::hreflocation('',$env{'request.filename'});
         &Apache::lonhtmlcommon::add_breadcrumb({
-            'text'  => 'Construction Space',
+            'text'  => 'Authoring Space',
             'href'  => &Apache::loncommon::authorspace($url),
         });
         &Apache::lonhtmlcommon::add_breadcrumb({
@@ -585,26 +605,34 @@ sub start_body {
         # FIXME Where are we?
     }
 
+        my $args = {'add_entries'    => $token->[2],
+                    'force_register' => 1,};
+        if ($target eq 'web') {
+            $args->{'print_suppress'} = 1;
+            if ($env{'request.use_absolute'}) {
+                $args->{'use_absolute'} = $env{'request.use_absolute'};
+            }
+        }
 	$currentstring = 
 	    &Apache::loncommon::start_page($Apache::londefdef::title,
 					   $Apache::londefdef::head
-					      .$extra_head,
-					   {'add_entries'    => $token->[2],
-#					    'no_title'       => 1,
-					    'force_register' => 1});
-
+					      .$extra_head,$args);
         my $header = '';
         if ($env{'request.state'} ne 'published' &&
             $env{'request.state'} ne 'construct') {
             $header=&Apache::lonmenu::constspaceform();
         }
         if ($env{'request.state'} ne 'published') {
-            $header.=&Apache::londefdef::edit_controls();
+            unless ($env{'form.inhibitmenu'} eq 'yes') {
+                $header.=&edit_controls();
+            }
         }
         if ($env{'request.state'} eq 'construct') {
-            $currentstring.=&Apache::loncommon::head_subbox(
-                                &Apache::loncommon::CSTR_pageheader()
-                               .$header);
+            unless ($env{'form.inhibitmenu'} eq 'yes') {
+                $currentstring.=&Apache::loncommon::head_subbox(
+                                    &Apache::loncommon::CSTR_pageheader()
+                                   .$header);
+            }
         } elsif ($env{'request.state'} eq 'edit') {
             $currentstring.=&Apache::loncommon::head_subbox($header);
         }
@@ -631,12 +659,39 @@ sub edit_controls {
     $result .= '
 <div><input type="submit" name="editmode" accesskey="e" value="'.&mt('Edit').'" />';
     if (($env{'request.course.id'}) && ($env{'form.forceedit'})) {
-        my $viewtext = &mt('Course View');
-        if (&Apache::loncommon::course_type() eq 'Community') {
-            $viewtext = &mt('Community View');
+        my $url=&Apache::lonnet::hreflocation('',$env{'request.filename'});
+        if ($url =~ /\.html?$/i) {
+            my ($cdom,$cnum);
+            if ($env{'request.course.id'}) {
+                $cdom = $env{'course.'.$env{'request.course.id'}.'.domain'};
+                $cnum = $env{'course.'.$env{'request.course.id'}.'.num'};
+                if ($env{'request.filename'} =~ m{/userfiles/supplemental/default|\d+/}) {
+                    if (&Apache::lonnet::is_course_upload($env{'request.filename'},
+                                                          $cnum,$cdom)) {
+                        &Apache::loncommon::get_unprocessed_cgi($ENV{'QUERY_STRING'},
+                                                                ['folderpath','title']);
+                    }
+                }
+            }
+            my ($symb,$itemtitle,$displayfile,$caller);
+            if ($url =~ m{^/uploaded/$cdom/$cnum/portfolio/syllabus/}) {
+                $itemtitle = &mt('Syllabus');
+                $caller = "/public/$cdom/$cnum/syllabus";
+            } else {
+                $caller = $url;
+                ($symb,$itemtitle,$displayfile) =
+                    &Apache::lonxml::get_courseupload_hierarchy($url,
+                                                                $env{'form.folderpath'},
+                                                                $env{'form.title'});
+            }
+            if (($symb ne '') || ($env{'httpref.'.$url} ne '') ||
+                ($url =~ m{^/uploaded/$cdom/$cnum/portfolio/syllabus/})) {
+                  $result .= ('&nbsp;' x 3).
+                             &Apache::lonhtmlcommon::dependencies_button()."\n".
+                             &Apache::lonhtmlcommon::dependencycheck_js($symb,
+                                 $itemtitle,$url,$env{'form.folderpath'},$caller)."\n";
+            }
         }
-        $result .= ('&nbsp;' x 3).'<input type="button" value="'.
-                   $viewtext.'" onclick="javascript:location.href=currentURL" />';
     }
     $result .= '</div>
 </div>
@@ -777,7 +832,7 @@ sub end_h1 {
 	$currentstring .= $token->[2];
     } elsif ($target eq 'tex') {
 	my $post='\vskip 0 mm ';
-	my $align=&Apache::lonxml::get_param('align',$parstack,$safeeval,undef,1);
+	my $align=lc(&Apache::lonxml::get_param('align',$parstack,$safeeval,undef,1));
 	if ($align eq 'center') {
 	    $post='\end{center}';
 	} elsif ($align eq 'left') {
@@ -1697,6 +1752,15 @@ sub start_a {
                     if (!&Apache::lonnet::allowed('bre',$linkurl)) {
                         if (&Apache::lonnet::is_on_map($url)) {
                             &Apache::lonxml::extlink($linkurl);
+                        } elsif ($env{'request.course.id'}) {
+                            my $cdom = $env{'course.'.$env{'request.course.id'}.'.domain'};
+                            my $cnum = $env{'course.'.$env{'request.course.id'}.'.num'};
+                            if ($linkurl =~ m{^([^/]|/uploaded/$cdom/$cnum/(docs|supplemental)/)}) {
+                                my $cleanhref = &clean_docs_httpref($linkurl,$url,$cdom,$cnum);
+                                if ($cleanhref) {
+                                    &Apache::lonxml::extlink($cleanhref);
+                                }
+                            }
                         }
                     }
                 }
@@ -2019,8 +2083,8 @@ sub end_dt {
 
 sub item_cleanup {
     my $item=&Apache::lonxml::endredirection();
-    $item=~s/\\begin{center}//g;
-    $item=~s/\\end{center}//g;
+    $item=~s/\\begin\{center}//g;
+    $item=~s/\\end\{center}//g;
     return $item;
 }
 
@@ -2709,7 +2773,9 @@ sub start_img {
 	my $inside = &Apache::lonxml::get_all_text("/img",$parser,$style);
 	return '';
     }
-    &Apache::lonxml::extlink($src);
+    unless ($src =~ m{^data\:image/gif;base64,}) {
+        &Apache::lonxml::extlink($src);
+    }
     my $currentstring = '';
     my $scaling = .3;
 
@@ -2719,8 +2785,10 @@ sub start_img {
         my $enc = ('yes' eq 
                    lc(&Apache::lonxml::get_param('encrypturl',$parstack,
                       $safeeval)));
-        $currentstring.=&Apache::lonenc::encrypt_ref($token,{'src'=>$src},
-                         $enc);
+        unless ($src =~ m{^data\:image/gif;base64,}) {
+            $currentstring.=&Apache::lonenc::encrypt_ref($token,{'src'=>$src},
+                            $enc);
+        }
 
     # and render unto TeX that which is LaTeX
     } elsif ($target eq 'tex') {
@@ -2763,7 +2831,7 @@ sub start_img {
 
 	# &Apache::lonxml::debug("LaTeX rendering = $latex_rendering image file: $src");
 
-	#if original bmp/gif/jpg/png file exist do following:
+	#if original bmp/gif/jpg/png/svg file exist do following:
 	my $origsrc=$src;
 	my ($path,$file) = &get_eps_image($src);
 	# &Apache::lonnet::logthis("Image source: $src result: $path $file");
@@ -3199,12 +3267,12 @@ sub end_externallink {
     return $currentstring;
 }
 
-#-- <blankspace heigth="">
+#-- <blankspace height="">
 sub start_blankspace {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
     my $currentstring = &end_p();	# closes off any unclosed <p>
     if ($target eq 'tex') {
-	my $howmuch = &Apache::lonxml::get_param('heigth',$parstack,$safeeval,undef,1);
+	my $howmuch = &Apache::lonxml::get_param('height',$parstack,$safeeval,undef,1);
 	$currentstring .= '\vskip '.$howmuch.' ';
     }
     return $currentstring;
@@ -3402,7 +3470,7 @@ sub start_caption {
     my $currentstring = '';
     if ($target eq 'web' || $target eq 'webgrade') {
 	$currentstring = $token->[4];     
-    } 
+    }
     return $currentstring;
 }
 
@@ -3410,7 +3478,7 @@ sub end_caption {
     my ($target,$token) = @_;
     my $currentstring = '';
     if ($target eq 'web' || $target eq 'webgrade') {
-	$currentstring = $token->[2];    
+	$currentstring = $token->[2];
     } 
     return $currentstring;
 }
@@ -3543,8 +3611,68 @@ sub start_iframe {
     my ($target,$token) = @_;
     my $currentstring = '';
     if ($target eq 'web' || $target eq 'webgrade') {
-	$currentstring = $token->[4];     
-    } 
+        my ($src,$url,$query);
+        if ($token->[2]->{'src'}) {
+            $src = $token->[2]->{'src'};
+        } elsif ($token->[2]->{'SRC'}) {
+            $src = $token->[2]->{'SRC'};
+        }
+        if ($src) {
+            ($url,$query) = ($src =~ /^([^?]+)\??([^?]*)$/);
+            if ($query =~ /inhibitmenu=yes/) {
+                $currentstring = $token->[4];
+            } else {
+                my $inhibit;
+                if ($url =~ m{^[^/.].*\.x?html?$}) {
+                    $inhibit = 1;
+                } elsif ($url =~ m{^/(uploaded|res)/.*\.x?html?$}) {
+                    $inhibit = 1;
+                }
+                if ($inhibit) {
+                    $currentstring = '<iframe ';
+                    foreach my $attrib (@{$token->[3]}) {
+                        if (lc($attrib) eq 'src') {
+                            if ($query) {
+                                $query.='&amp;inhibitmenu=yes';
+                            } else {
+                                $query = 'inhibitmenu=yes';
+                            } 
+                            $currentstring .= 'src="'.$url.'?'.$query.'" ';
+                        } else {
+                            $currentstring .= lc($attrib).'="'.$token->[2]->{$attrib}.'" ';
+                        }
+                    }
+                    $currentstring =~ s/\s+$//;
+                    if ($token->[4] =~ m{/>$}) {
+                        $currentstring .= ' />';
+                    } else {
+                        $currentstring .= '>';
+                    }
+                } else {
+                    $currentstring = $token->[4];
+                }
+            }
+            if (($url !~ m{^https?://}) && ($env{'request.course.id'})) {
+                my $docuri = &Apache::lonnet::hreflocation('',$env{'request.filename'});
+                my $cdom = $env{'course.'.$env{'request.course.id'}.'.domain'};
+                my $cnum = $env{'course.'.$env{'request.course.id'}.'.num'};
+                if ($url =~ m{^([^/]|/uploaded/)}) {
+                    my $cleanhref = &clean_docs_httpref($url,$docuri,$cdom,$cnum);
+                    if ($cleanhref) {
+                        &Apache::lonxml::extlink($cleanhref);
+                    }
+                } elsif (($url =~ m{/res/$LONCAPA::domain_re/}) && ($docuri =~ m{^\Q/uploaded/$cdom/$cnum/docs/\E})) {
+                    if (!&Apache::lonnet::allowed('bre',$url)) {
+                        if (&Apache::lonnet::is_on_map($url)) {
+                            &Apache::lonxml::extlink($url);
+                        }
+                    }
+                }
+            }
+        } else {
+            $currentstring = $token->[4];
+        }
+    }
     return $currentstring;
 }
 
@@ -4150,10 +4278,10 @@ sub resize_image {
 	    $height_param=$TeXwidth/$old_width_param*$height_param;
 	}
     } elsif ($TeXheight) {
-	$height_param = $TeXheight;
 	if ($height_param) {
 	    $width_param  = $TeXheight/$height_param*$width_param;
 	}
+	$height_param = $TeXheight;
     } elsif ($width) {
 	my $old_width_param=$width_param;
 	$width_param = $width*$scaling;
@@ -4217,8 +4345,8 @@ sub get_eps_image {
 	&Apache::lonnet::repcopy($orig_src); # Failure is not completely fatal.
     }
     &Apache::lonxml::debug("get_eps_image: Original image: $orig_src");
-    my ($spath, $sname, $sext) = &fileparse($src, qr/\.(bmp|gif|png|jpg|jpeg)/i);
-    $src=~s/\.(bmp|gif|png|jpg|jpeg)$/\.eps/i;
+    my ($spath, $sname, $sext) = &fileparse($src, qr/\.(bmp|gif|png|jpg|jpeg|svg)/i);
+    $src=~s/\.(bmp|gif|png|jpg|jpeg|svg)$/\.eps/i;
     $src=&Apache::lonnet::filelocation($Apache::lonxml::pwd[-1],$src);
     &Apache::lonxml::debug("Filelocation gives: $src");
     if (! -e $src) {
@@ -4332,17 +4460,17 @@ sub LATEX_length {
     $garbage=~s/^\s+(\S.*)/$1/;#space before 
     $garbage=~s/(.*\S)\s+$/$1/;#space after 
     $garbage=~s/(\s)+/$1/;#only one space
-    $garbage=~s/(\\begin{([^\}]+)}|\\end{([^\}]+)})//g;#remove LaTeX \begin{...} and \end{...}
-    $garbage=~s/(\$\_\{|\$\_|\$\^{|\$\^|\}\$)//g;#remove $_{,$_,$^{,$^,}$
+    $garbage=~s/(\\begin\{([^\}]+)}|\\end\{([^\}]+)})//g;#remove LaTeX \begin{...} and \end{...}
+    $garbage=~s/(\$\_\{|\$\_|\$\^\{|\$\^|\}\$)//g;#remove $_{,$_,$^{,$^,}$
     $garbage=~s/([^\\])\$/$1/g;#$
-    $garbage=~s/(\\ensuremath\{\_\{|\\ensuremath\{\_|\\ensuremath\{\^{|\\ensuremath\{\^|\})//g;#remove \ensuremath{...}
+    $garbage=~s/(\\ensuremath\{\_\{|\\ensuremath\{\_|\\ensuremath\{\^\{|\\ensuremath\{\^|\})//g;#remove \ensuremath{...}
    $garbage=~s/(\\alpha|\\beta|\\gamma|\\delta|\\epsilon|\\verepsilon|\\zeta|\\eta|\\theta|\\vartheta|\\iota|\\kappa|\\lambda|\\mu|\\nu|\\xi|\\pi|\\varpi|\\rho|\\varrho|\\sigma|\\varsigma|\\tau|\\upsilon|\\phi|\\varphi|\\chi|\\psi|\\omega|\\Gamma|\\Delta|\\Theta|\\Lambda|\\Xi|\\Pi|\\Sigma|\\Upsilon|\\Phi|\\Psi|\\Omega)/1/g;
     $garbage=~s/(\\pm|\\mp|\\times|\\div|\\cdot|\\ast|\\star|\\dagger|\\ddagger|\\amalg|\\cap|\\cup|\\uplus|\\sqcap|\\sqcup|\\vee|\\wedge|\\oplus|\\ominus|\\otimes|\\circ|\\bullet|\\diamond|\\lhd|\\rhd|\\unlhd|\\unrhd|\\oslash|\\odot|\\bigcirc|\\Box|\\Diamond|\\bigtriangleup|\\bigtriangledown|\\triangleleft|\\triangleright|\\setminus|\\wr)/1/g;
     $garbage=~s/(\\le|\\ll|\\leq|\\ge|\\geq|\\gg|\\neq|\\doreq|\\sim|\\simeq|\\subset|\\subseteq|\\sqsubset|\\sqsubseteq|\\in|\\vdash|\\models|\\supset|\\supseteq|\\sqsupset|\\sqsupseteq|\\ni|\\dash|\\perp|\\approx|\\cong|\\equiv|\\propto|\\prec|\\preceq|\\parallel|\\asymp|\\smile|\\frown|\\bowtie|\\succ|\\succeq|\\mid)/1/g;
     $garbage=~s/(\\not<|\\\\not\\le|\\not\\prec|\\not\\preceq|\\not\\subset|\\not\\subseteq|\\not\\sqsubseteq|\\not\\in|\\not>|\\not\\ge|\\not\\succ|\\notsucceq|\\not\\supset|\\notsupseteq|\\not\\sqsupseteq|\\notin|\\not=|\\not\\equiv|\\not\\sim|\\not\\simeq|\\not\\approx|\\not\\cong|\\not\\asymp)/1/g;
     $garbage=~s/(\\leftarrow|\\gets|\\Leftarrow|\\rightarrow|\\to|\\Rightarrow|\\leftrightarrow|\\Leftrightarrow|\\mapsto|\\hookleftarrow|\\leftharpoonup|\\leftkarpoondown|\\rightleftharpoons|\\longleftarrow|\\Longleftarrow|\\longrightarrow|\\Longrightarrow|\\longleftrightarrow|\\Longleftrightarrow|\\longmapsto|\\hookrightarrow|\\rightharpoonup|\\rightharpoondown|\\uparrow|\\Uparrow|\\downarrow|\\Downarrow|\\updownarrow|\\Updownarrow|\\nearrow|\\searrow|\\swarrow|\\nwarrow)/11/g;
     $garbage=~s/(\\aleph|\\hbar|\\imath|\\jmath|\\ell|\\wp|\\Re|\\Im|\\mho|\\prime|\\emptyset|\\nabla|\\surd|\\partial|\\top|\\bot|\\vdash|\\dashv|\\forall|\\exists|\\neg|\\flat|\\natural|\\sharp|\\\||\\angle|\\backslash|\\Box|\\Diamond|\\triangle|\\clubsuit|\\diamondsuit|\\heartsuit|\\spadesuit|\\Join|\\infty)/11/g;
-    $garbage=~s/(\\hat{([^}]+)}|\\check{([^}]+)}|\\dot{([^}]+)}|\\breve{([^}]+)}|\\acute{([^}]+)}|\\ddot{([^}]+)}|\\grave{([^}]+)}|\\tilde{([^}]+)}|\\mathring{([^}]+)}|\\bar{([^}]+)}|\\vec{([^}]+)})/$1/g;
+    $garbage=~s/(\\hat\{([^}]+)}|\\check\{([^}]+)}|\\dot\{([^}]+)}|\\breve\{([^}]+)}|\\acute\{([^}]+)}|\\ddot\{([^}]+)}|\\grave\{([^}]+)}|\\tilde\{([^}]+)}|\\mathring\{([^}]+)}|\\bar\{([^}]+)}|\\vec\{([^}]+)})/$1/g;
     #remove some other LaTeX command
     $garbage=~s|\\(\w+)\\|\\|g;	 
     $garbage=~s|\\(\w+)(\s*)|$2|g;	 	 
@@ -4444,40 +4572,34 @@ sub latex_header {
 	($mode eq 'batchmode')) {$currentstring .='\batchmode';} 
     $currentstring .= '\newcommand{\keephidden}[1]{}'.
 	'\renewcommand{\deg}{$^{\circ}$}'.
-	'\usepackage{multirow}'.
-	'\usepackage{longtable}'.
-	'\usepackage{textcomp}'.
-	'\usepackage{makeidx}'.
-	'\usepackage[dvips]{graphicx}'.
-	'\usepackage{wrapfig}'.
-	'\usepackage{picins}'.
+	'\usepackage{multirow}'."\n".
+	'\usepackage{longtable}'."\n".
+	'\usepackage{textcomp}'."\n".
+	'\usepackage{makeidx}'."\n".
+	'\usepackage[dvips]{graphicx}'."\n".
+	'\usepackage{wrapfig}'."\n".
+	'\usepackage{picins}'."\n".
 	'\usepackage[T1]{fontenc}'."\n".
 	'\usepackage{lmodern}'."\n".
 	'\usepackage[postscript]{ucs}'."\n".
 	'\usepackage[utf8x]{inputenc}'."\n".
-	'\usepackage{pifont}' ."\n".
+	'\usepackage{pifont}'."\n".
 	'\usepackage{latexsym}'."\n".
-	'\usepackage{epsfig}'.
-	"\\usepackage{xtab}\n".
-	"\\usepackage{tabularx}\n".
-	"\\usepackage{booktabs}\n".
-	"\\usepackage{array}\n".
-	"\\usepackage{colortbl}\n".
-	"\\usepackage{xcolor}\n".
-	'\usepackage{calc}'.
-	'\usepackage{amsmath}'.
-    '\usepackage{soul}',
-	'\usepackage{amssymb}'.
-	'\usepackage{amsfonts}'.
-	'\usepackage{amsthm}'.
-	'\usepackage{amscd}'
-        .'\usepackage{picins}\usepackage{calc}'."\n". # From lonprintout.pm
-	'\usepackage[T1]{fontenc}'."\n".
-	'\usepackage{lmodern}'."\n".
-	'\usepackage[postscript]{ucs}'."\n".
-	'\usepackage[utf8x]{inputenc}'."\n".
-	'\usepackage{pifont}'  . "\n";
-	
+	'\usepackage{epsfig}'."\n".
+	'\usepackage{xtab}'."\n".
+	'\usepackage{tabularx}'."\n".
+	'\usepackage{booktabs}'."\n".
+	'\usepackage{array}'."\n".
+	'\usepackage{colortbl}'."\n".
+	'\usepackage{xcolor}'."\n".
+	'\usepackage{calc}'."\n".
+	'\usepackage{amsmath}'."\n".
+	'\usepackage{soul}'."\n".
+	'\usepackage{amssymb}'."\n".
+	'\usepackage{amsfonts}'."\n".
+	'\usepackage{amsthm}'."\n".
+	'\usepackage{amscd}'."\n".
+	'\usepackage{actuarialangle}'."\n";
     if($env{'form.pdfFormFields'} eq 'yes') {
 	$currentstring .= '\usepackage{hyperref}'.
 	    '\usepackage{eforms}'.
@@ -4492,6 +4614,62 @@ sub latex_header {
 
 }
 
+sub clean_docs_httpref {
+    my ($href,$docuri,$cdom,$cnum) = @_;
+    if ($docuri eq '') {
+        $docuri = &Apache::lonnet::hreflocation('',$env{'request.filename'});
+    }
+    if ($cdom eq '') {
+        $cdom = $env{'course.'.$env{'request.course.id'}.'.domain'};
+    }
+    if ($cnum eq '') {
+        $cnum = $env{'course.'.$env{'request.course.id'}.'.num'};
+    }
+    my $cleanhref;
+    if ($docuri =~ m{^(\Q/uploaded/$cdom/$cnum/\E(?:docs|supplemental)/)(.+/)[^/]+$}) {
+        my $prefix = $1;
+        my $relpath = $2;
+        my ($hrefpath,$fname);
+        if ($href =~ m{^/}) {
+            if ($href =~ m{^\Q$prefix\E(.+/)([^/]+)$}) {
+                $hrefpath = $1;
+                $fname = $2;
+            } else {
+                return $cleanhref;
+            }
+        } else {
+            if ($href =~ m{/}) {  
+                (my $path,$fname) = ($href =~ m{^(.*)/([^/]*)$});
+                $hrefpath = $relpath.$path;
+                if ($path eq '') {
+                    $hrefpath =~ s{/$}{};
+                }
+            } else {
+                $fname = $href;
+                $hrefpath = $relpath;
+                $hrefpath =~ s{/$}{};
+            }
+        }
+        if ($fname ne '') {
+            my $cleanrelpath;
+            foreach my $dir (split(/\//,$hrefpath)) {
+                next if ($dir eq '.');
+                if ($dir eq '..') {
+                    $cleanrelpath =~ s{([^/]+/)$}{};
+                } else {
+                    $cleanrelpath .= $dir.'/';
+                }
+            }
+            if ($cleanrelpath ne '') {
+                $cleanhref = $prefix.$cleanrelpath.$fname;
+            } else {
+                $cleanhref = $prefix.$fname;
+            }
+        }
+    }
+    return $cleanhref;
+}
+
 =pod
 
 =head1 NAME
@@ -4586,7 +4764,23 @@ described at http://www.lon-capa.org.
      	   I'm in a table....
      	}
 
-
+=item clean_docs_httpref($href,$docuri,$cdom,$cnum)
+        HTML pages uploaded to a course which contain dependencies either from iframes,
+        javascript files or objects (FlashPlayerSwf, MediaSrc, XMPSrc, ConfigurationSrc,
+        and PosterImageSrc) for which dependency is another file uploaded to the same
+        course.
+
+        Required input: 
+        href - dependency (either a relative URL, or an absolute URL)
+        Optional inputs:
+        docuri - URL of HTML page containing the dependency
+        cdom - Course domain
+        cnum - CourseID
+
+        Output:
+        returns an absolute URL constructed from the href provided, and the calling context.
+        (this will be null, if the URL does not begin: /uploaded/$cdom/$cnum/docs/ or
+        /uploaded/$cdom/$cnum/supplemental/).
 
 =back