推荐一个Gem, Rlayout，简化content_for，erb定义layout

Rails Layout Extension

Feature
=======
1. simplifying content_for usage by extracting key/value pair from content_for data like YAML and setting them as content_for variables
简化content_for的使用，采用类似YAML的key/value方式定义content_for变量
2. let erb file can determine layout by changing the default behavior of layout determining, just like java's sitemesh
通过改变默认的layout获取方式，使erb也可以定义layout，类似java的sitemesh

Setup
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put the following line into your rails initializer, or bottom of environment.rb
把下列这行代码加到rails的initializer里，或者environment.rb的最后
require 'rlayout'

Usage
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1. simplifying content_for

<% content_for :config do %>
title: This is my title
panel: This is my panel
<% end %>

do the same thing as the following:

<%- content_for :title do -%>
This is my title
<%- end -%> 
<%- content_for :panel do -%>
This is my panel
<%- end -%> 

2. determining layout in erb file

<% content_for :config do %>
#note：key layout won't be transferred to a content_for variable, it is only used to determine a view layout
layout: happy
<% end %>