Added AssetTagHelper that provides methods for linking a HTML page together with other assets, such as javascripts, stylesheets, and feeds.

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@689 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

4 files changed, 107 insertions, 1 deletions

diff --git a/actionpack/CHANGELOG b/actionpack/CHANGELOG
index 342f96f3ee..e153726ffc 100644
--- a/actionpack/CHANGELOG
+++ b/actionpack/CHANGELOG
@@ -1,5 +1,7 @@
 *SVN*
 
+* Added AssetTagHelper that provides methods for linking a HTML page together with other assets, such as javascripts, stylesheets, and feeds.
+
 * Added FormTagHelper that provides a number of methods for creating form tags that doesn't rely on conventions with an object assigned to the template like FormHelper does. With the FormTagHelper, you provide the names and values yourself.
 
 * Added Iran and Irak to the countries list used by FormOptions#country_select and FormOptions#country_options_for_select
diff --git a/actionpack/lib/action_view/helpers/asset_tag_helper.rb b/actionpack/lib/action_view/helpers/asset_tag_helper.rb
new file mode 100644
index 0000000000..33914b2144
--- /dev/null
+++ b/actionpack/lib/action_view/helpers/asset_tag_helper.rb
@@ -0,0 +1,59 @@
+require 'cgi'
+require File.dirname(__FILE__) + '/url_helper'
+require File.dirname(__FILE__) + '/tag_helper'
+
+module ActionView
+  module Helpers
+    # Provides methods for linking a HTML page together with other assets, such as javascripts, stylesheets, and feeds.
+    module AssetTagHelper
+      # Returns a link tag that browsers and news readers can use to auto-detect a RSS or ATOM feed for this page. The +type+ can
+      # either be <tt>:rss</tt> (default) or <tt>:atom</tt> and the +options+ follow the url_for style of declaring a link target.
+      #
+      # Examples:
+      #   auto_discovery_link_tag # => 
+      #     <link rel="alternate" type="application/rss+xml" title="RSS" href="http://www.curenthost.com/controller/action" />
+      #   auto_discovery_link_tag(:atom) # => 
+      #     <link rel="alternate" type="application/atom+xml" title="ATOM" href="http://www.curenthost.com/controller/action" />
+      #   auto_discovery_link_tag(:rss, :action => "feed") # => 
+      #     <link rel="alternate" type="application/atom+xml" title="ATOM" href="http://www.curenthost.com/controller/feed" />
+      def auto_discovery_link_tag(type = :rss, options = {})
+        tag(
+          "link", "rel" => "alternate", "type" => "application/#{type}+xml", "title" => type.to_s.upcase, 
+          "href" => url_for(options.merge(:only_path => false))
+        )
+      end
+
+      # Returns a script include tag per source given as argument. Examples:
+      #
+      #   javascript_include_tag "xmlhr" # =>
+      #     <script language="JavaScript" type="text/javascript" src="/javascripts/xmlhr.js"></script>
+      #
+      #   javascript_include_tag "common.javascript", "/elsewhere/cools" # =>
+      #     <script language="JavaScript" type="text/javascript" src="/javascripts/common.javascript"></script>
+      #     <script language="JavaScript" type="text/javascript" src="/elsewhere/cools.js"></script>
+      def javascript_include_tag(*sources)
+        sources.collect { |source|
+          source = "/javascripts/#{source}" unless source.include?("/")
+          source = "#{source}.js" unless source.include?(".")
+          content_tag("script", "", "language" => "JavaScript", "type" => "text/javascript", "src" => source)
+        }.join("\n")
+      end
+    
+      # Returns a css link tag per source given as argument. Examples:
+      #
+      #   stylesheet_link_tag "style" # =>
+      #     <link href="/stylesheets/style.css" media="screen" rel="Stylesheet" type="text/css" />
+      #
+      #   stylesheet_link_tag "random.styles", "/css/stylish" # =>
+      #     <link href="/stylesheets/random.styles" media="screen" rel="Stylesheet" type="text/css" />
+      #     <link href="/css/stylish.css" media="screen" rel="Stylesheet" type="text/css" />
+      def stylesheet_link_tag(*sources)
+        sources.collect { |source| 
+          source = "/stylesheets/#{source}" unless source.include?("/")
+          source = "#{source}.css" unless source.include?(".")
+          tag("link", "rel" => "Stylesheet", "type" => "text/css", "media" => "screen", "href" => source)
+        }.join("\n")
+      end
+    end
+  end
+end
diff --git a/actionpack/test/template/asset_tag_helper_test.rb b/actionpack/test/template/asset_tag_helper_test.rb
new file mode 100644
index 0000000000..a8d01f18f5
--- /dev/null
+++ b/actionpack/test/template/asset_tag_helper_test.rb
@@ -0,0 +1,45 @@
+require 'test/unit'
+require File.dirname(__FILE__) + '/../../lib/action_view/helpers/asset_tag_helper'
+
+class AssetTagHelperTest < Test::Unit::TestCase
+  include ActionView::Helpers::TagHelper
+  include ActionView::Helpers::UrlHelper
+  include ActionView::Helpers::AssetTagHelper
+
+  def setup
+    @controller = Class.new do
+      def url_for(options, *parameters_for_method_reference)
+        "http://www.world.com"
+      end
+    end
+    @controller = @controller.new
+  end
+
+  AutoDiscoveryToTag = {
+    %(auto_discovery_link_tag) => %(<link href="http://www.world.com" rel="alternate" title="RSS" type="application/rss+xml" />),
+    %(auto_discovery_link_tag(:atom)) => %(<link href="http://www.world.com" rel="alternate" title="ATOM" type="application/atom+xml" />),
+    %(auto_discovery_link_tag(:rss, :action => "feed")) => %(<link href="http://www.world.com" rel="alternate" title="RSS" type="application/rss+xml" />),
+  }
+
+  JavascriptIncludeToTag = {
+    %(javascript_include_tag("xmlhr")) => %(<script language="JavaScript" src="/javascripts/xmlhr.js" type="text/javascript"></script>),
+    %(javascript_include_tag("common.javascript", "/elsewhere/cools")) => %(<script language="JavaScript" src="/javascripts/common.javascript" type="text/javascript"></script>\n<script language="JavaScript" src="/elsewhere/cools.js" type="text/javascript"></script>),
+  }
+
+  StyleLinkToTag = {
+    %(stylesheet_link_tag("style")) => %(<link href="/stylesheets/style.css" media="screen" rel="Stylesheet" type="text/css" />),
+    %(stylesheet_link_tag("random.styles", "/css/stylish")) => %(<link href="/stylesheets/random.styles" media="screen" rel="Stylesheet" type="text/css" />\n<link href="/css/stylish.css" media="screen" rel="Stylesheet" type="text/css" />)
+  }
+
+  def test_auto_discovery
+    AutoDiscoveryToTag.each { |method, tag| assert_equal(tag, eval(method)) }
+  end
+
+  def test_javascript_include
+    JavascriptIncludeToTag.each { |method, tag| assert_equal(tag, eval(method)) }
+  end
+
+  def test_style_link
+    StyleLinkToTag.each { |method, tag| assert_equal(tag, eval(method)) }
+  end
+end
\ No newline at end of file
diff --git a/actionpack/test/template/form_tag_helper_test.rb b/actionpack/test/template/form_tag_helper_test.rb
index 25da1937d4..6036dd4b50 100644
--- a/actionpack/test/template/form_tag_helper_test.rb
+++ b/actionpack/test/template/form_tag_helper_test.rb
@@ -1,7 +1,7 @@
 require 'test/unit'
 require File.dirname(__FILE__) + '/../../lib/action_view/helpers/form_tag_helper'
 
-class TagHelperTest < Test::Unit::TestCase
+class FormTagHelperTest < Test::Unit::TestCase
   include ActionView::Helpers::TagHelper
   include ActionView::Helpers::FormTagHelper