Add block support to button_tag helper

As per the HTML 4.01 spec:

  Buttons created with the BUTTON element function just like buttons
  created with the INPUT element, but they offer richer rendering
  possibilities: the BUTTON element may have content. For example, a
  BUTTON element that contains an image functions like and may resemble
  an INPUT element whose type is set to "image", but the BUTTON element
  type allows content.

Since rich content is the main purpose of the <button> element, it makes
sense for the button_tag helper to accept a block.

http://www.w3.org/TR/html401/interact/forms.html#edef-BUTTON
http://dev.w3.org/html5/spec/the-button-element.html#the-button-element

Signed-off-by: Santiago Pastorino and Emilio Tagua <santiago+emilioe@wyeworks.com>

2 files changed, 18 insertions, 4 deletions

diff --git a/actionpack/lib/action_view/helpers/form_tag_helper.rb b/actionpack/lib/action_view/helpers/form_tag_helper.rb
index c4a5a683d0..71f8534cbf 100644
--- a/actionpack/lib/action_view/helpers/form_tag_helper.rb
+++ b/actionpack/lib/action_view/helpers/form_tag_helper.rb
@@ -414,7 +414,8 @@ module ActionView
       # <tt>reset</tt>button or a generic button which can be used in
       # JavaScript, for example. You can use the button tag as a regular
       # submit tag but it isn't supported in legacy browsers. However,
-      # button tag allows richer labels such as images and emphasis.
+      # the button tag allows richer labels such as images and emphasis,
+      # so this helper will also accept a block.
       #
       # ==== Options
       # * <tt>:confirm => 'question?'</tt> - If present, the
@@ -433,7 +434,9 @@ module ActionView
       #   button_tag
       #   # => <button name="button" type="submit">Button</button>
       #
-      #   button_tag "<strong>Ask me!</strong>", :type => 'button'
+      #   button_tag(:type => 'button') do
+      #     content_tag(:strong, 'Ask me!')
+      #   end
       #   # => <button name="button" type="button">
       #          <strong>Ask me!</strong>
       #        </button>
@@ -442,7 +445,9 @@ module ActionView
       #   # => <button data-disable-with="Please wait..." name="button"
       #                type="submit">Checkout</button>
       #
-      def button_tag(label = "Button", options = {})
+      def button_tag(content_or_options = nil, options = nil, &block)
+        options = content_or_options if block_given? && content_or_options.is_a?(Hash)
+        options ||= {}
         options.stringify_keys!
 
         if disable_with = options.delete("disable_with")
@@ -455,7 +460,7 @@ module ActionView
 
         options.reverse_merge! 'name' => 'button', 'type' => 'submit'
 
-        content_tag :button, label, { "type" => options.delete("type") }.update(options)
+        content_tag :button, content_or_options || 'Button', options, &block
       end
 
       # Displays an image which when clicked will submit the form.
diff --git a/actionpack/test/template/form_tag_helper_test.rb b/actionpack/test/template/form_tag_helper_test.rb
index c22af258c3..f8671f2980 100644
--- a/actionpack/test/template/form_tag_helper_test.rb
+++ b/actionpack/test/template/form_tag_helper_test.rb
@@ -427,6 +427,15 @@ class FormTagHelperTest < ActionView::TestCase
     )
   end
 
+  def test_button_tag_with_block
+    assert_dom_equal('<button name="button" type="submit">Content</button>', button_tag { 'Content' })
+  end
+
+  def test_button_tag_with_block_and_options
+    output = button_tag(:name => 'temptation', :type => 'button') { content_tag(:strong, 'Do not press me') }
+    assert_dom_equal('<button name="temptation" type="button"><strong>Do not press me</strong></button>', output)
+  end
+
   def test_image_submit_tag_with_confirmation
     assert_dom_equal(
       %(<input type="image" src="/images/save.gif" data-confirm="Are you sure?" />),