Added link_to_image(src, options = {}, html_options = {}, *parameters_for_method_reference)

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@105 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

actionpack/CHANGELOG

 *SVN*
 
+* Added link_to_image(src, options = {}, html_options = {}, *parameters_for_method_reference). Documentation:
+
+    Creates a link tag to the image residing at the +src+ using an URL created by the set of +options+. See the valid options in
+    link:classes/ActionController/Base.html#M000021. It's also possible to pass a string instead of an options hash to
+    get a link tag that just points without consideration. The <tt>html_options</tt> works jointly for the image and ahref tag by
+    letting the following special values enter the options on the image and the rest goes to the ahref:
+    
+    ::alt: If no alt text is given, the file name part of the +src+ is used (capitalized and without the extension)
+    ::size: Supplied as "XxY", so "30x45" becomes width="30" and height="45"
+    ::align: Sets the alignment, no special features
+    
+    The +src+ can be supplied as a... 
+    * full path, like "/my_images/image.gif"
+    * file name, like "rss.gif", that gets expanded to "/images/rss.gif"
+    * file name without extension, like "logo", that gets expanded to "/images/logo.png"
+
 * Fixed to_input_field_tag so it no longer explicitly uses InstanceTag.value if value was specified in the options hash [evl]
 
 * Added the possibility of having validate be protected for assert_(in)valid_column #263 [Tobias Luetke]

actionpack/lib/action_view/helpers/url_helper.rb

@@ -25,6 +25,43 @@ def link_to(name, options = {}, html_options = {}, *parameters_for_method_refere
         end
       end
 
+      # Creates a link tag to the image residing at the +src+ using an URL created by the set of +options+. See the valid options in
+      # link:classes/ActionController/Base.html#M000021. It's also possible to pass a string instead of an options hash to
+      # get a link tag that just points without consideration. The <tt>html_options</tt> works jointly for the image and ahref tag by
+      # letting the following special values enter the options on the image and the rest goes to the ahref:
+      #
+      # ::alt: If no alt text is given, the file name part of the +src+ is used (capitalized and without the extension)
+      # ::size: Supplied as "XxY", so "30x45" becomes width="30" and height="45"
+      # ::align: Sets the alignment, no special features
+      #
+      # The +src+ can be supplied as a... 
+      # * full path, like "/my_images/image.gif"
+      # * file name, like "rss.gif", that gets expanded to "/images/rss.gif"
+      # * file name without extension, like "logo", that gets expanded to "/images/logo.png"
+      def link_to_image(src, options = {}, html_options = {}, *parameters_for_method_reference)
+        image_options = { "src" => src.include?("/") ? src : "/images/#{src}" }
+        image_options["src"] = image_options["src"] + ".png" unless image_options["src"].include?(".")
+        
+        if html_options["alt"]
+          image_options["alt"] = html_options["alt"]
+          html_options.delete "alt"
+        else
+          image_options["alt"] = src.split("/").last.split(".").first.capitalize
+        end
+
+        if html_options["size"]
+          image_options["width"], image_options["height"] = html_options["size"].split("x")
+          html_options.delete "size"
+        end
+        
+        if html_options["align"]
+          image_options["align"] = html_options["align"]
+          html_options.delete "align"
+        end
+
+        link_to(tag("img", image_options), options, html_options, *parameters_for_method_reference)
+      end
+
       # Creates a link tag of the given +name+ using an URL created by the set of +options+, unless the current 
       # controller, action, and id are the same as the link's, in which case only the name is returned (or the
       # given block is yielded, if one exists). This is useful for creating link bars where you don't want to link 

actionpack/test/template/url_helper_test.rb

@@ -27,6 +27,18 @@ def test_link_tag_with_javascript_confirm
     )
   end
   
+  def test_link_to_image
+    assert_equal(
+      "<a href=\"http://www.world.com\"><img alt=\"Rss\" height=\"45\" src=\"/images/rss.png\" width=\"30\" /></a>", 
+      link_to_image("rss", "http://www.world.com", "size" => "30x45")
+    )
+
+    assert_equal(
+      "<a class=\"admin\" href=\"http://www.world.com\"><img alt=\"Feed\" height=\"45\" src=\"/images/rss.gif\" width=\"30\" /></a>", 
+      link_to_image("rss.gif", "http://www.world.com", "size" => "30x45", "alt" => "Feed", "class" => "admin")
+    )
+  end
+  
   def test_link_unless_current
     @params = { "controller" => "weblog", "action" => "show"}
     assert_equal "Showing", link_to_unless_current("Showing", :action => "show", :controller => "weblog")