渲染应用程序范围的视图以及Ruby on Rails中的特定视图

Question

Hello StackOverflow community,

I would like to know on how can I achieve application wide plus page specific view on Ruby on Rails.

I put all of my navbar, footer etc in the application wide view (application.html.erb) so it acts as a base layout (which I think the real purpose of application wide view) to every view on my app.

From what I see now, Rails puts both code of say, application wide view and home/index view on runtime. Links to stylesheets, scripts etc is a no problem and I am glad that they're being imported in app-wide view, saves time.

How do I specify Rails to import the assets & contents for a specific view, for example, home/index?

How do I form the code in the following manner or so?

app wide view (meta tags, navbar, header, global stylesheets) + page specific content (title, body) + app wide view (footer, javascripts)

I think best way to approach it is to split it to header, body and footer. Should I create another file and let it act as footer and let app.html.erb be the header?

Thanks!

Answer 1

The most common approach is to include both the header and footer in your Layout , yielding the page content in between.

If you have assets that you want to include only in particular pages, or that need to be rendered elsewhere in your layout, you can use content_for and yield to achieve this.

For example, in your page view:

<% content_for :title do %>The title of this page!<% end %>

And in your layout, where you want the title tag to be output:

<title><%= content_for?(:title) ? yield(:title) : "Default page title goes here" %></title>

The same approach can be used for javascripts or stylesheets that you want to include only on particular pages.

For example, in some page that needs jQuery:

<% content_for :per_page_javascripts do %>    
  <script type="text/javascript" src="//ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js"></script>
<% end %>

And in your layout (the header or footer, wherever you think JS should go):

<%= yield(:per_page_javascripts) %>

Here's a guide that might help: http://guides.rubyonrails.org/layouts_and_rendering.html#using-the-content-for-method