More agressively set the context for our custom Markdown renderer, and fall back if we still don't manage to get it right. Fixes #662.

middleman-core/lib/middleman-core/renderers/markdown.rb

@@ -29,6 +29,7 @@ module Middleman
               if config[:markdown_engine] == :redcarpet
                 require "middleman-core/renderers/redcarpet"
                 ::Tilt.prefer(::Middleman::Renderers::RedcarpetTemplate)
+                MiddlemanRedcarpetHTML.middleman_app = self
               elsif !config[:markdown_engine].nil?
                 # Map symbols to classes
                 markdown_engine_klass = if config[:markdown_engine].is_a? Symbol

middleman-core/lib/middleman-core/renderers/redcarpet.rb

@@ -4,15 +4,6 @@ module Middleman
   module Renderers
 
     class RedcarpetTemplate < ::Tilt::RedcarpetTemplate::Redcarpet2
-
-      def initialize(*args, &block)
-        super
-        
-        if @options.has_key?(:context)
-          @context = @options[:context]
-        end
-      end
-
       # Overwrite built-in Tilt version.
       # Don't overload :renderer option with smartypants
       # Support renderer-level options
@@ -39,27 +30,31 @@ module Middleman
 
         renderer.new(render_options)
       end
-
-      def evaluate(context, locals, &block)
-        @context ||= context
-
-        if @engine.renderer.respond_to? :middleman_app=
-          @engine.renderer.middleman_app = @context
-        end
-        super
-      end
     end
 
     # Custom Redcarpet renderer that uses our helpers for images and links
     class MiddlemanRedcarpetHTML < ::Redcarpet::Render::HTML
-      attr_accessor :middleman_app
+      cattr_accessor :middleman_app
 
       def image(link, title, alt_text)
-        middleman_app.image_tag(link, :title => title, :alt => alt_text)
+        if middleman_app && middleman_app.respond_to?(:image_tag)
+          middleman_app.image_tag(link, :title => title, :alt => alt_text)
+        else
+          img = "<img src=\"#{link}\""
+          img << " title=\"#{title}\"" if title
+          img << " alt=\"#{alt_text}\"" if alt_text
+          img << ">"
+        end
       end
 
       def link(link, title, content)
-        middleman_app.link_to(content, link, :title => title)
+        if middleman_app && middleman_app.respond_to?(:link_to)
+          middleman_app.link_to(content, link, :title => title)
+        else
+          a = "<a href=\"#{link}\""
+          a << " title=\"#{title}\"" if title
+          a << ">#{content}</a>"
+        end
       end
     end