= ViewVariantResponder

== Installation
In your Gemfile, add this line:
  gem "view_variant_responder"

== Configuration
This is only a module, to use it, you have to create your own responder:
  # lib/app_responder.rb
  class AppResponder < ActionController::Responder
    include Responders::ViewVariantResponder
  end

If you're using any other responders, like Responders::FlashResponder, then include these there too.

Finally you need to configure your application to use it:
  require "app_responder"
  class ApplicationController < ActionController::Base
    self.responder = AppResponder
  end

== Usage
Let's assume you want to show an overlay view of a post. Your controller already should look something like this:
  class PostsController < ApplicationController
    respond_to :html

    def show
      @post = Post.find(params[:id])
      respond_with(@post)
    end
  end

Now you only need to add a separate view for the overlay
* app/views/posts/show.html.erb - Your usual view
* app/views/posts/show.overlay.html.haml - Your overlay view

To get this view using jquery for example, you'll do something like this:
  $.ajax({
    url: "/posts/5",
    dataType: "html",
    headers: {
      "X-View-Variant": "overlay"
    },
    success: function(content) {
      // Voila, your overlay content is now here
    }
  });