accept a block in button_to helper

Make possible to use a block in button_to helper if button text is hard
to fit into the name parameter, e.g.:

    <%= button_to [:make_happy, @user] do %>
      Make happy <strong><%= @user.name %></strong>
    <% end %>
    # => "<form method="post" action="/users/1/make_happy" class="button_to">
    #      <div>
    #        <button type="submit">
    #          Make happy <strong>Name</strong>
    #        </button>
    #      </div>
    #    </form>"

3 files changed, 51 insertions, 3 deletions

diff --git a/actionpack/CHANGELOG.md b/actionpack/CHANGELOG.md
index 2e7b3190fc..b907eea3c1 100644
--- a/actionpack/CHANGELOG.md
+++ b/actionpack/CHANGELOG.md
@@ -1,5 +1,21 @@
 ## Rails 4.0.0 (unreleased) ##
 
+*   Make possible to use a block in button_to helper if button text is hard
+    to fit into the name parameter, e.g.:
+
+        <%= button_to [:make_happy, @user] do %>
+          Make happy <strong><%= @user.name %></strong>
+        <% end %>
+        # => "<form method="post" action="/users/1/make_happy" class="button_to">
+        #      <div>
+        #        <button type="submit">
+        #          Make happy <strong>Name</strong>
+        #        </button>
+        #      </div>
+        #    </form>"
+
+    *Sergey Nartimov*
+
 *   change a way of ordering helpers from several directories. Previously,
     when loading helpers from multiple paths, all of the helpers files were
     gathered into one array an then they were sorted. Helpers from different
diff --git a/actionpack/lib/action_view/helpers/url_helper.rb b/actionpack/lib/action_view/helpers/url_helper.rb
index 7e69547dab..a4b10bc68a 100644
--- a/actionpack/lib/action_view/helpers/url_helper.rb
+++ b/actionpack/lib/action_view/helpers/url_helper.rb
@@ -294,6 +294,16 @@ module ActionView
       #   #      <div><input value="New" type="submit" /></div>
       #   #    </form>"
       #
+      #   <%= button_to [:make_happy, @user] do %>
+      #     Make happy <strong><%= @user.name %></strong>
+      #   <% end %>
+      #   # => "<form method="post" action="/users/1/make_happy" class="button_to">
+      #   #      <div>
+      #   #        <button type="submit">
+      #   #          Make happy <strong><%= @user.name %></strong>
+      #   #        </button>
+      #   #      </div>
+      #   #    </form>"
       #
       #   <%= button_to "New", :action => "new", :form_class => "new-thing" %>
       #   # => "<form method="post" action="/controller/new" class="new-thing">
@@ -331,7 +341,16 @@ module ActionView
       #   #       </div>
       #   #     </form>"
       #   #
-      def button_to(name, options = {}, html_options = {})
+      def button_to(*args, &block)
+        if block_given?
+          options      = args[0] || {}
+          html_options = args[1] || {}
+        else
+          name         = args[0]
+          options      = args[1] || {}
+          html_options = args[2] || {}
+        end
+
         html_options = html_options.stringify_keys
         convert_boolean_attributes!(html_options, %w(disabled))
 
@@ -350,9 +369,15 @@ module ActionView
         request_token_tag = form_method == 'post' ? token_tag : ''
 
         html_options = convert_options_to_data_attributes(options, html_options)
-        html_options.merge!("type" => "submit", "value" => name || url)
+        html_options['type'] = 'submit'
+
+        button = if block_given?
+          content_tag('button', html_options, &block)
+        else
+          tag('input', html_options.merge('value' => name || url))
+        end
 
-        inner_tags = method_tag.safe_concat tag('input', html_options).safe_concat request_token_tag
+        inner_tags = method_tag.safe_concat(button).safe_concat(request_token_tag)
         content_tag('form', content_tag('div', inner_tags), form_options)
       end
 
diff --git a/actionpack/test/template/url_helper_test.rb b/actionpack/test/template/url_helper_test.rb
index fb5b35bac6..365a86ab91 100644
--- a/actionpack/test/template/url_helper_test.rb
+++ b/actionpack/test/template/url_helper_test.rb
@@ -144,6 +144,13 @@ class UrlHelperTest < ActiveSupport::TestCase
     )
   end
 
+  def test_button_to_with_block
+    assert_dom_equal(
+      "<form method=\"post\" action=\"http://www.example.com\" class=\"button_to\"><div><button type=\"submit\"><span>Hello</span></button></div></form>",
+      button_to("http://www.example.com") { content_tag(:span, 'Hello') }
+    )
+  end
+
   def test_link_tag_with_straight_url
     assert_dom_equal "<a href=\"http://www.example.com\">Hello</a>", link_to("Hello", "http://www.example.com")
   end