Make floated TOCs in wikis compatible with the Liquid engine

The floated tags (>toc and <toc) are invalid syntax because of the < and >
characters. We transform them to toc_left and toc_right instead.

app/helpers/application_helper.rb

@@ -740,7 +740,7 @@ module ApplicationHelper
     end
   end
 
-  TOC_RE = /<p>\{\{([<>]?)toc\}\}<\/p>/i unless const_defined?(:TOC_RE)
+  TOC_RE = /<p>\{%\s*toc(_right|_left)?\s*%\}<\/p>/i unless const_defined?(:TOC_RE)
 
   # Renders the TOC with given headings
   def replace_toc(text, headings)
@@ -749,8 +749,8 @@ module ApplicationHelper
         ''
       else
         div_class = 'toc'
-        div_class << ' right' if $1 == '>'
-        div_class << ' left' if $1 == '<'
+        div_class << ' right' if $1 == '_right'
+        div_class << ' left' if $1 == '_left'
         out = "<fieldset class='header_collapsible collapsible'><legend onclick='toggleFieldset(this);'></legend><div>"
         out << "<ul class=\"#{div_class}\"><li>"
         root = headings.map(&:first).min

lib/chili_project/liquid/legacy.rb

@@ -63,5 +63,11 @@ module ChiliProject
     Legacy.add('child_pages', :tag)
     Legacy.add('hello_world', :tag)
     Legacy.add('include', :tag)
+
+    # Transform the old textile TOC tags to syntax suported by liquid
+    Legacy.add('toc', :tag)
+    Legacy.add('>toc', :tag, "toc_right")
+    Legacy.add('<toc', :tag, "toc_left")
+
   end
 end

lib/chili_project/liquid/tags.rb

@@ -28,6 +28,15 @@ module ChiliProject::Liquid
     register_tag('include', Include, :html => true)
     register_tag('tag_list', TagList, :html => true)
     register_tag('variable_list', VariableList, :html => true)
+
+    # Output these tags again as they were typed
+    # These are to be handled later
+    register_tag('toc', Identity, :html => true)
+    register_tag('toc_left', Identity, :html => true)
+    register_tag('toc_right', Identity, :html => true)
+
+    # See ChiliProject::Liquid::Legacy for the definition of legacy tags,
+    # most of which are also defined here
   end
 end