Dynamic title with content for

Now all the our web pages share the same title, which is it a good practice for UX and SEO reason.

So we want dynamic title on each page. In the way, the title is a variable that varies depends on the current showing page. Take photo showing as example, the title may be the photo title.

We learnt to define @variable in controller that passes to the view. But title is responded by view instead of controller. Let’s use the view approach – content_for

In the views/layouts/application.html.erb file

  <%- if content_for? :page_title -%>
    <%= yield :page_title %> – Photo Gallery
  <%- else -%>
    Photo Gallery
  <%- end -%>

in the views/photos/show.html.erb file, prepend the following code snippet at the beginning, before any existing content.

<% content_for :page_title do
end %>

And the result screenshot. Note how the title reflects the photo title.

Content for title

content_for is defined in view. It is used for defining specific content in that view.

For example, a specific page — let say ‘about’ — may want to include one special CSS file. Since CSS is linked inside the <head> tag, we can’t link it anywhere inside that about view file because the view file is included into the <body> tag. That’s where we need the content_for.

In the application.html.erb layout file

<!DOCTYPE html>
  <%- if content_for? :special_css_files -%>
    <%= yield :special_css_files %>
  <%- end -%>

<%= yield %> <!-- this is where the view file included. -->


Now assume our about view is about.html.erb, we can define a special_css_files section that will be included (yield) in the layout inside the <head> section.

<% content_for :special_css_files do %>
  <link rel='stylesheet' type='text/css' media='all' href='special.css'>
<% end %>
<!-- The rest of about content goes here -->

What’s next? We’re going to take a look at “Adding album resource”.

overlaied image when clicked on thumbnail

Makzan | Ruby on rails 101 | Table of Content