Added that render :json will automatically call .to_json unless its being passed a string [DHH] Added Mime::Type.register_alias for dealing with different formats using the same mime type [DHH]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@7520 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

3 files changed, 34 insertions, 2 deletions

diff --git a/actionpack/CHANGELOG b/actionpack/CHANGELOG
index 0d71df79f9..ee19d49c70 100644
--- a/actionpack/CHANGELOG
+++ b/actionpack/CHANGELOG
@@ -1,5 +1,30 @@
 *SVN*
 
+* Added Mime::Type.register_alias for dealing with different formats using the same mime type [DHH]. Example:
+
+    class PostsController < ApplicationController
+      before_filter :adjust_format_for_iphone
+
+      def index
+        @posts = Post.find(:all)
+        
+        respond_to do |format|
+          format.html   # => renders index.html.erb and uses "text/html" as the content type
+          format.iphone # => renders index.iphone.erb and uses "text/html" as the content type
+        end
+      end
+
+
+      private
+        def adjust_format_for_iphone
+          if request.env["HTTP_USER_AGENT"] && request.env["HTTP_USER_AGENT"][/iPhone/]
+            request.format = :iphone
+          end
+        end
+    end
+
+* Added that render :json will automatically call .to_json unless it's being passed a string [DHH].
+
 * Autolink behaves well with emails embedded in URLs.  #7313 [Jeremy McAnally, tarmo]
 
 * Fixed that default layouts did not take the format into account #9564 [lifofifo]
diff --git a/actionpack/lib/action_controller/base.rb b/actionpack/lib/action_controller/base.rb
index 9a3ab651ac..4630103119 100755
--- a/actionpack/lib/action_controller/base.rb
+++ b/actionpack/lib/action_controller/base.rb
@@ -826,6 +826,7 @@ module ActionController #:nodoc:
             render_for_text(xml.respond_to?(:to_xml) ? xml.to_xml : xml, options[:status])
 
           elsif json = options[:json]
+            json = json.to_json unless json.is_a?(String)
             json = "#{options[:callback]}(#{json})" unless options[:callback].blank?
             response.content_type = Mime::JSON
             render_for_text(json, options[:status])
diff --git a/actionpack/lib/action_controller/mime_type.rb b/actionpack/lib/action_controller/mime_type.rb
index 7c7faefa46..29b7723d76 100644
--- a/actionpack/lib/action_controller/mime_type.rb
+++ b/actionpack/lib/action_controller/mime_type.rb
@@ -52,12 +52,18 @@ module Mime
         EXTENSION_LOOKUP[extension]
       end
 
-      def register(string, symbol, mime_type_synonyms = [], extension_synonyms = [])
+      # Registers an alias that's not usd on mime type lookup, but can be referenced directly. Especially useful for
+      # rendering different HTML versions depending on the user agent, like an iPhone.
+      def register_alias(string, symbol, extension_synonyms = [])
+        register(string, symbol, [], extension_synonyms, true)
+      end
+
+      def register(string, symbol, mime_type_synonyms = [], extension_synonyms = [], skip_lookup = false)
         Mime.send :const_set, symbol.to_s.upcase, Type.new(string, symbol, mime_type_synonyms)
 
         SET << Mime.send(:const_get, symbol.to_s.upcase)
 
-        ([string] + mime_type_synonyms).each { |string| LOOKUP[string] = SET.last }
+        ([string] + mime_type_synonyms).each { |string| LOOKUP[string] = SET.last } unless skip_lookup
         ([symbol.to_s] + extension_synonyms).each { |ext| EXTENSION_LOOKUP[ext] = SET.last }
       end