Ruby on Rails：无法将内容插入到yield块中

Question

I have a partial called _main_nav.html.erb in views/layout folder, this is content file:

<% content_for :main_navigation do %>
  <h1>Something must here</h1>
<% end %>

In my _header.html.erb file, i used yield to insert content:

... 
<%= yield :main_navigation %>  
<nav id="utility" class="nav-collapse">
...  

But when i visit home page, it does'n appear h1 element, i have wrong somewhere?

Answer 1

The issue is that you are trying to yield content from a view that isn't currently being rendered.

You would need to do:

_header.html.erb

... 
<%= render "layouts/main_nav" %>
<%= yield :main_navigation %>  
<nav id="utility" class="nav-collapse">
... 

_main_nav.html.erb

<% content_for :main_navigation do %>
  <h1>Something must here</h1>
<% end %>

http://guides.rubyonrails.org/layouts_and_rendering.html#understanding-yield