respond_to recognizes JSON. render :json => @person.to_json automatically sets the content type and takes a :callback option to specify a client-side function to call using the rendered JSON as an argument. References #4185.

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@5694 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

actionpack/CHANGELOG

@@ -1,5 +1,11 @@
 *SVN*
 
+* respond_to recognizes JSON. render :json => @person.to_json automatically sets the content type and takes a :callback option to specify a client-side function to call using the rendered JSON as an argument.  #4185 [Scott Raymond, eventualbuddha]
+    # text/x-json response with body 'Element.show({:name: "David"})'
+    respond_to do |format|
+      format.json { render :json => { :name => "David" }.to_json, :callback => 'Element.show' }
+    end
+
 * Makes :discard_year work without breaking multi-attribute parsing in AR.  #1260, #3800 [sean@ardismg.com, jmartin@desertflood.com, stephen@touset.org, Bob Silva]
 
 * Adds html id attribute to date helper elements.  #1050, #1382 [mortonda@dgrmm.net, David North, Bob Silva]

actionpack/lib/action_controller/base.rb

@@ -650,6 +650,20 @@ module ActionController #:nodoc:
       #
       # _Deprecation_ _notice_: This used to have the signature <tt>render_text("text", status = 200)</tt>
       #
+      # === Rendering JSON
+      #
+      # Rendering JSON sets the content type to text/x-json and optionally wraps the JSON in a callback. It is expected
+      # that the response will be eval'd for use as a data structure.
+      #
+      #   # Renders '{name: "David"}'
+      #   render :json => {:name => "David"}.to_json
+      #
+      # Sometimes the result isn't handled directly by a script (such as when the request comes from a SCRIPT tag),
+      # so the callback option is provided for these cases.
+      #
+      #   # Renders 'show({name: "David"})'
+      #   render :json => {:name => "David"}.to_json, :callback => 'show'
+      #
       # === Rendering an inline template
       #
       # Rendering of an inline template works as a cross between text and action rendering where the source for the template
@@ -733,6 +747,12 @@ module ActionController #:nodoc:
 
           elsif xml = options[:xml]
             render_xml(xml, options[:status])
+          
+          elsif json = options[:json]
+            render_json(json, options[:callback], options[:status])
+          
+          elsif yaml = options[:yaml]
+            render_yaml(yaml, options[:status])
 
           elsif partial = options[:partial]
             partial = default_template_name if partial == true
@@ -813,6 +833,18 @@ module ActionController #:nodoc:
         response.content_type = Mime::XML
         render_text(xml, status)
       end
+      
+      def render_json(json, callback = nil, status = nil) #:nodoc:
+        json = "#{callback}(#{json})" unless callback.blank?
+        
+        response.content_type = Mime::JSON
+        render_text(json, status)
+      end
+      
+      def render_yaml(yaml, status = nil) #:nodoc:
+        response.content_type = Mime::YAML
+        render_text(yaml, status)
+      end
 
       def render_nothing(status = nil) #:nodoc:
         render_text(' ', status)

actionpack/lib/action_controller/mime_types.rb

@@ -2,6 +2,7 @@ Mime::Type.register "*/*", :all
 Mime::Type.register "text/plain", :text
 Mime::Type.register "text/html", :html, %w( application/xhtml+xml ), %w( xhtml )
 Mime::Type.register "text/javascript", :js, %w( application/javascript application/x-javascript )
+Mime::Type.register "text/x-json", :json, %w( application/x-json )
 Mime::Type.register "text/calendar", :ics
 Mime::Type.register "text/csv", :csv
 Mime::Type.register "application/xml", :xml, %w( text/xml application/x-xml )

actionpack/lib/action_controller/request.rb

@@ -66,6 +66,8 @@ module ActionController
               content_type = 'application/x-yaml'
             when 'xml'
               content_type = 'application/xml'
+            when 'json'
+              content_type = 'application/x-json'
             end
           end
           

actionpack/test/controller/mime_responds_test.rb

@@ -19,6 +19,13 @@ class RespondToController < ActionController::Base
       type.all  { render :text => "Nothing" }
     end
   end
+  
+  def json_or_yaml
+    respond_to do |type|
+      type.json { render :text => "JSON" }
+      type.yaml { render :yaml => "YAML" }
+    end
+  end
 
   def html_or_xml
     respond_to do |type|
@@ -163,6 +170,19 @@ class MimeControllerTest < Test::Unit::TestCase
     get :just_xml
     assert_response 406
   end
+  
+  def test_json_or_yaml
+    get :json_or_yaml
+    assert_equal 'JSON', @response.body
+    
+    @request.env["HTTP_ACCEPT"] = "text/yaml"
+    get :json_or_yaml
+    assert_equal 'YAML', @response.body
+    
+    @request.env["HTTP_ACCEPT"] = "text/x-json"
+    get :json_or_yaml
+    assert_equal 'JSON', @response.body
+  end
 
   def test_js_or_anything
     @request.env["HTTP_ACCEPT"] = "text/javascript, */*"

actionpack/test/controller/render_test.rb

@@ -38,6 +38,14 @@ class TestController < ActionController::Base
   def render_text_hello_world
     render_text "hello world"
   end
+  
+  def render_json_hello_world
+    render_json({:hello => 'world'}.to_json)
+  end
+  
+  def render_json_hello_world_with_callback
+    render_json({:hello => 'world'}.to_json, 'alert')
+  end
 
   def render_custom_code
     render_text "hello world", "404 Moved"
@@ -163,6 +171,16 @@ class RenderTest < Test::Unit::TestCase
     get :render_text_hello_world
     assert_equal "hello world", @response.body
   end
+  
+  def test_do_with_render_json
+    get :render_json_hello_world
+    assert_equal '{hello: "world"}', @response.body
+  end
+  
+  def test_do_with_render_json_with_callback
+    get :render_json_hello_world_with_callback
+    assert_equal 'alert({hello: "world"})', @response.body
+  end
 
   def test_do_with_render_custom_code
     get :render_custom_code