Added AtomFeedHelper (slightly improved from the atom_feed_helper plugin) [DHH]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@7529 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

actionpack/CHANGELOG

@@ -1,5 +1,7 @@
 *SVN*
 
+* Added AtomFeedHelper (slightly improved from the atom_feed_helper plugin) [DHH]
+
 * Prevent errors when generating routes for uncountable resources, (i.e. sheep where plural == singluar).   map.resources :sheep now creates sheep_index_url for the collection and sheep_url for the specific item.  [Koz]
 
 * Added support for HTTP Only cookies (works in IE6+ and FF 2.0.5+) as an improvement for XSS attacks #8895 [lifo/Spakman]

actionpack/lib/action_view/helpers/atom_feed_helper.rb

@@ -0,0 +1,111 @@
+# Adds easy defaults to writing Atom feeds with the Builder template engine (this does not work on ERb or any other
+# template languages).
+module ActionView
+  module Helpers #:nodoc:
+    module AtomFeedHelper
+      # Full usage example:
+      #
+      #   config/routes.rb:
+      #     ActionController::Routing::Routes.draw do |map|
+      #       map.resources :posts
+      #       map.root :controller => "posts"
+      #     end
+      #
+      #   app/controllers/posts_controller.rb:
+      #     class PostsController < ApplicationController::Base
+      #       # GET /posts.html
+      #       # GET /posts.atom
+      #       def index
+      #         @posts = Post.find(:all)
+      #         
+      #         respond_to do |format|
+      #           format.html
+      #           format.atom
+      #         end
+      #       end
+      #     end
+      #
+      #   app/views/posts/index.atom.builder:
+      #     atom_feed do |feed|
+      #       feed.title("My great blog!")
+      #       feed.updated((@posts.first.created_at))
+      #     
+      #       for post in @posts
+      #         feed.entry(post) do |entry|
+      #           entry.title(post.title)
+      #           entry.content(post.body, :type => 'html')
+      #     
+      #           entry.author do |author|
+      #             author.name("DHH")
+      #           end
+      #         end
+      #       end
+      #     end
+      #
+      # The options are for atom_feed are:
+      #
+      # * <tt>:language</tt>: Defaults to "en-US".
+      # * <tt>:root_url</tt>: The HTML alternative that this feed is doubling for. Defaults to / on the current host.
+      # * <tt>:url</tt>: The URL for this feed. Defaults to the current URL.
+      #
+      # atom_feed yields a AtomFeedBuilder instance.
+      def atom_feed(options = {}, &block)
+        xml = options[:xml] || eval("xml", block.binding)
+        xml.instruct!
+
+        xml.feed "xml:lang" => options[:language] || "en-US", "xmlns" => 'http://www.w3.org/2005/Atom' do
+          xml.id("tag:#{request.host}:#{request.request_uri.split(".")[0].gsub("/", "")}")      
+          xml.link(:rel => 'alternate', :type => 'text/html', :href => options[:root_url] || (request.protocol + request.host_with_port))
+
+          if options[:url]
+            xml.link(:rel => 'self', :type => 'application/atom+xml', :href => options[:url] || request.url)
+          end
+
+          yield AtomFeedBuilder.new(xml, self)
+        end
+      end
+
+
+      class AtomFeedBuilder
+        def initialize(xml, view)
+          @xml, @view = xml, view
+        end
+        
+        # Accepts a Date or Time object and inserts it in the proper format. If nil is passed, current time in UTC is used.
+        def updated(date_or_time = nil)
+          @xml.updated((date_or_time || Time.now.utc).xmlschema)
+        end
+
+        # Creates an entry tag for a specific record and prefills the id using class and id.
+        #
+        # Options:
+        #
+        # * <tt>:updated</tt>: Time of update. Defaults to the created_at attribute on the record if one such exists.
+        # * <tt>:published</tt>: Time first published. Defaults to the updated_at attribute on the record if one such exists.
+        # * <tt>:url</tt>: The URL for this entry. Defaults to the polymorphic_url for the record.
+        def entry(record, options = {})
+          @xml.entry do 
+            @xml.id("tag:#{@view.request.host_with_port}:#{record.class}#{record.id}")
+
+            if options[:published] || (record.respond_to?(:created_at) && record.created_at)
+              @xml.published((options[:published] || record.created_at).xmlschema)
+            end
+
+            if options[:updated] || (record.respond_to?(:updated_at) && record.updated_at)
+              @xml.updated((options[:updated] || record.updated_at).xmlschema)
+            end
+
+            @xml.link(:rel => 'alternate', :type => 'text/html', :href => options[:url] || @view.polymorphic_url(record))
+
+            yield @xml
+          end
+        end
+
+        private
+          def method_missing(method, *arguments)
+            @xml.__send__(method, *arguments)
+          end
+      end
+    end
+  end
+end

actionpack/test/template/atom_feed_helper_test.rb

@@ -0,0 +1,101 @@
+require "#{File.dirname(__FILE__)}/../abstract_unit"
+
+Post = Struct.new(:id, :to_param, :title, :body, :updated_at, :created_at)
+
+class PostsController < ActionController::Base
+  FEEDS = {}
+  FEEDS["defaults"] = <<-EOT
+        atom_feed do |feed|
+          feed.title("My great blog!")
+          feed.updated((@posts.first.created_at))
+
+          for post in @posts
+            feed.entry(post) do |entry|
+              entry.title(post.title)
+              entry.content(post.body, :type => 'html')
+
+              entry.author do |author|
+                author.name("DHH")
+              end
+            end
+          end
+        end
+    EOT
+    FEEDS["entry_options"] = <<-EOT
+        atom_feed do |feed|
+          feed.title("My great blog!")
+          feed.updated((@posts.first.created_at))
+
+          for post in @posts
+            feed.entry(post, :url => "/otherstuff/" + post.to_param, :updated => Time.utc(2007, 1, post.id)) do |entry|
+              entry.title(post.title)
+              entry.content(post.body, :type => 'html')
+
+              entry.author do |author|
+                author.name("DHH")
+              end
+            end
+          end
+        end
+    EOT
+
+  def index
+    @posts = [
+      Post.new(1, "1", "Hello One", "Something <i>COOL!</i>", Time.utc(2007, 12, 12, 15), Time.utc(2007, 12, 12, 15)),
+      Post.new(2, "2", "Hello Two", "Something Boring", Time.utc(2007, 12, 12, 15)),
+    ]
+    
+    render :inline => FEEDS[params[:id]], :type => :builder
+  end
+end
+
+class RenderTest < Test::Unit::TestCase
+  def setup
+    @request    = ActionController::TestRequest.new
+    @response   = ActionController::TestResponse.new
+    @controller = PostsController.new
+
+    @request.host = "www.nextangle.com"
+  end
+  
+  def test_feed_should_use_default_language_if_none_is_given
+    with_restful_routing(:posts) do
+      get :index, :id => "defaults"
+      assert_match %r{xml:lang="en-US"}, @response.body
+    end
+  end
+  
+  def test_feed_should_include_two_entries
+    with_restful_routing(:posts) do
+      get :index, :id => "defaults"
+      assert_select "entry", 2
+    end
+  end
+  
+  def test_entry_should_only_use_published_if_created_at_is_present
+    with_restful_routing(:posts) do
+      get :index, :id => "defaults"
+      assert_select "published", 1
+    end
+  end
+
+  def test_entry_with_prefilled_options_should_use_those_instead_of_querying_the_record
+    with_restful_routing(:posts) do
+      get :index, :id => "entry_options"
+
+      assert_select "updated", Time.utc(2007, 1, 1).xmlschema
+      assert_select "updated", Time.utc(2007, 1, 2).xmlschema
+    end
+  end
+
+
+  private
+    def with_restful_routing(resources)
+      with_routing do |set|
+        set.draw do |map|
+          map.resources(resources)
+        end
+        yield
+      end
+    end
+end