--- loncom/homework/structuretags.pm	2011/12/12 12:07:45	1.497.2.3
+++ loncom/homework/structuretags.pm	2011/12/10 17:53:45	1.498
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA 
 # definition of tags that give a structure to a document
 #
-# $Id: structuretags.pm,v 1.497.2.3 2011/12/12 12:07:45 foxr Exp $
+# $Id: structuretags.pm,v 1.498 2011/12/10 17:53:45 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -960,6 +960,9 @@ sub reset_problem_globals {
     undef(%Apache::lonhomework::history);
     undef(%Apache::lonhomework::results);
     undef($Apache::inputtags::part);
+    if ($type eq 'Task') {
+        undef($Apache::inputtags::slot_name);
+    }
 #don't undef this, lonhomework.pm takes care of this, we use this to 
 #detect if we try to do 2 problems in one file
 #   undef($Apache::lonhomework::parsing_a_problem);
@@ -1539,100 +1542,54 @@ sub end_block {
     }
     return $result;
 }
-#
-#  <languageblock [include='lang1,lang2...'] [exclude='lang1,lang2...']>
-#  ...
-#  </languageblock>
-#
-#   This declares the intent to provide content that can be rendered in the
-#   set of languages in the include specificatino but not in the exclude
-#   specification.  If a currently preferred language is in the include list
-#   the content in the <languageblock>...</languageblock> is rendered
-#   If the currently preferred language is in the exclude list,
-#   the content in the <languageblock>..></languageblock is not rendered.
-#
-#   Pathalogical case handling:
-#     - Include specified, without the preferred language but exclude  specified
-#       also without the preferred langauge results in rendering the block.
-#     - Exclude specified without include and excluden not containing a 
-#       preferred language renders the block.
-#     - Include and exclude both specifying the preferred language does not
-#       render the block.
-#     - If neither include/exclude is specified, the block gets rendered.
-#
-#  This tag has no effect when target is in {edit, modified}
-#
+
 sub start_languageblock {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
 
-    my $result = '';
+    my $result;
 
     if ($target eq 'web' || $target eq 'grade'   || $target eq 'answer' ||
 	$target eq 'tex' || $target eq 'analyze' || $target eq 'webgrade') {
 	my $include = $token->[2]->{'include'};
 	my $exclude = $token->[2]->{'exclude'};
         my @preferred_languages=&Apache::lonlocal::preferred_languages();
-
-        # This should not even happen, since we should at least have the server language
-
-        if (!$preferred_languages[0]) { 
-	    $preferred_languages[0]='en'; 
-	}
-
-        # Now loop over all languages in order of preference
-
+# This should not even happen, since we should at least have the server language
+        if (!$preferred_languages[0]) { $preferred_languages[0]='en'; }
+# Now loop over all languages in order of preference
         foreach my $preferred_language (@preferred_languages) {
-
-	    # If neither include/nor exlude is present the block is going
-	    # to get rendered.
-
-           my $render=1;
+# If the languageblock has no arguments, show the contents
+           $result=1;
            my $found=0;
-           
-	   #  If include is specified,  don't render the block
-	   #  unless the preferred language is included in the set.
-
+# Do we have an include argument?
 	   if ($include) {
-              $render=0;
+# If include is specified, by default, don't render the block
+              $result=0;
               foreach my $included_language (split(/\,/,$include)) {
+# ... but if my preferred language is included, render it
                  if ($included_language eq $preferred_language) {
-                    $render=1; 
+                    $result=1; 
                     $found=1; 
-		    last;	# Only need to find the first.
                  }
               }
 	   }
-           # Do we have an exclude argument?
-	   # If so, and one of the languages matches a preferred language
-	   # inhibit rendering the block.  Note that in the pathalogical case the
-	   # author has specified a preferred language in both the include and exclude
-	   # attribte exclude is preferred.  
-
+# Do we have an exclude argument?
            if ($exclude) {
-              $render=1;
+              $result=1;
               foreach my $excluded_language (split(/\,/,$exclude)) {
                  if ($excluded_language eq $preferred_language) {
-                    $render=0;
+                    $result=0;
                     $found=1;
-		    last;	# Only need to find the first.
                  }
               }
 	   }
-           if ($found) { 
-	       last; 		# Done on any match of include or exclude.
-	   }
+           if ($found) { last; }
         }
-	# If $render not true skip the entire block until </languageblock>
-	#
-
-	if ( ! $render ) {
+	if ( ! $result ) {
 	    my $skip=&Apache::lonxml::get_all_text("/languageblock",$parser,
 						   $style);
 	    &Apache::lonxml::debug("skipping ahead :$skip: $$parser[-1]");
 	}
-	# If $render is true, we've not skipped the contents of the <languageglock>
-	# and the normal loncapa processing flow will render it as a matter of course.
-
+	$result='';
     } elsif ($target eq 'edit') {
 	$result .=&Apache::edit::tag_start($target,$token);
 	$result .=&Apache::edit::text_arg(&mt('Include Language:'),'include',
@@ -1657,47 +1614,9 @@ sub end_languageblock {
     }
     return $result;
 }
-#  languagblock specific tags:
-{
-    # For chunks of a resource that has translations, this hash contains
-    # the translations available indexed by language name.
-    #
 
-    my %available_texts;       
-
-    # <translated> starts a block of a resource that has multiple translations.
-    # See the <lang> tag as well.
-    # When </translated> is encountered if there is a translation for the 
-    # currently preferred language, that is rendered inthe web/tex/webgrade
-    # targets.  Otherwise, the default text is rendered.
-    #
-    # Note that <lang> is only registered for the duration of the 
-    #  <translated>...</translated> block 
-    #
-    # Pathalogical case handling:
-    #   - If there is no <lang> that specifies a 'default' and there is no
-    #     translation that matches a preferred language, nothing is rendered.
-    #   - Nested <translated>...</translated> might be linguistically supported by
-    #     XML due to the stack nature of tag registration(?) however the rendered
-    #     output will be incorrect because there is only one %available_texts
-    #     has and end_translated clears it.
-    #   - Material outside of a <lang>...</lang> block within the
-    #     <translated>...<translated> block won't render either e.g.:
-    #    <translated>
-    #      The following will be in your preferred langauge:
-    #      <lang which='en'>
-    #         This section in english
-    #      </lang>
-    #      <lang which='sgeiso'>
-    #         Hier es ist auf Deutsch.
-    #      </lang>
-    #      <lang which='sfriso'>
-    #         En Francais
-    #      </lang>
-    #    </translated>
-    #
-    #    The introductory text prior to the first <lang> tag is not rendered.
-    #
+{
+    my %available_texts;
     sub start_translated {
 	my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
 	&Apache::lonxml::register('Apache::structuretags',('lang'));
@@ -1723,42 +1642,7 @@ sub end_languageblock {
 	return $result;
     }
 
-    # <lang [which='language-name'] [other='lang1,lang2...']>  
-    #  Specifies that the block contained within it is a translation 
-    #  for a specific language specified by the 'which' attribute. The
-    #   'other' attribute can be used by itself or in conjunction with
-    #   which to specify this tag _may_ be used as a translation for some
-    #   list of languages. e.g.:  <lang which='senisoUS' other='senisoCA,senisoAU,seniso'>
-    #   specifying that the block provides a translation for US (primary)
-    #   Canadian, Australian and UK Englush.
-    #   
-    # Comment: this seems a bit silly why not just support a list of languages
-    #           e.g. <lang which='l1,l2...'> and ditch the other attribute?
-    #
-    #  Effect:
-    #    The material within the <lang>..</lang> block is stored in the
-    #    specified set of $available_texts hash entries, the appropriate one
-    #    is selected at </translated> time.
-    #
-    #  Pathalogical case handling:
-    #    If a language occurs multiple times within a <translated> block,
-    #    only the last one is rendered e.g.:
-    #
-    #    <translated>
-    #       <lang which='senisoUS', other='senisoCA,senisoAU,seniso'>
-    #          Red green color blindness is quite common affecting about 7.8% of 
-    #          the male population, but onloy about .65% of the female population.
-    #       </lang>
-    #          Red green colour blindness is quite common affecting about 7.8% of 
-    #          the male population, but onloy about .65% of the female population.
-    #       <lang which='seniso', other='senisoCA,senisoAU'>
-    #     </translated>
-    #
-    #    renders the correct spelling of color (colour) for people who have specified
-    #    a preferred language that is one of the British Commonwealth languages
-    #    even though those are also listed as valid selections for the US english
-    #    <lang> block.
-    #
+
     sub start_lang {
 	my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
 	if ($target eq 'web' || $target eq 'grade'   || $target eq 'answer' ||
@@ -1789,8 +1673,7 @@ sub end_languageblock {
 	}
 	return '';
     }
-}				# end langauge block specific tags.
-
+}
 
 sub start_instructorcomment {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;