Merge pull request #419 from trans/metadata

Add support for embedded page metadata.

lib/gollum/markup.rb

@@ -7,6 +7,8 @@ module Gollum
 
   class Markup
     attr_accessor :toc
+    attr_reader   :metadata
+
     # Initialize a new Markup object.
     #
     # page - The Gollum::Page.
@@ -27,6 +29,7 @@ module Gollum
       @wsdmap  = {}
       @premap  = {}
       @toc = nil
+      @metadata = nil
     end
 
     # Render the content with Gollum wiki syntax on top of the file's own
@@ -43,6 +46,7 @@ module Gollum
         @wiki.sanitizer
 
       data = @data.dup
+      data = extract_metadata(data)
       data = extract_code(data)
       data = extract_tex(data)
       data = extract_wsd(data)
@@ -565,6 +569,29 @@ module Gollum
       data
     end
 
+    #########################################################################
+    #
+    # Metadata
+    #
+    #########################################################################
+
+    # Extract metadata for data and build metadata table. Metadata
+    # is content found between `<!-- ---` and `-->` markers, and must
+    # be a valid YAML mapping.
+    #
+    # Returns the String of formatted data with metadata removed.
+    def extract_metadata(data)
+      @metadata ||= {}
+      data.gsub(/\<\!--+\s+---(.*?)--+\>/m) do
+        yaml = @wiki.sanitizer.clean($1)
+        hash = YAML.load(yaml)
+        if Hash === hash
+          @metadata.update(hash)
+        end
+        ''
+      end
+    end
+
     # Hook for getting the formatted value of extracted tag data.
     #
     # type - Symbol value identifying what type of data is being extracted.