How to set title in controller? - ruby-on-rails

Question

View application.html.erb contains following content
<title><%= content_for?(:title) ? yield(:title) : t(:stocktaking_title) %></title>
How can I pass data to this view from the controller's method?
I mean use symbol :title. I'm don't know Ruby well.
class WelcomeController < ApplicationController
def download
view_context.content_for(:title, "My Awesome Title") # doesn't work :(
end
end
Rails 4.1.9, ruby 2.0.0 (2014-05-08) [universal.x86_64-darwin14]

Answer 1

The prependeded # character to a variable is what exposes the variable to the view scope. In your controller:
def show
#title = "My Title"
end
Will let any rendered template file access it using:
<%= #title %>
Clearly, you're looking for some sort of title processing logic. Perhaps you could try replacing the code in your application.html.erb file with something like:
<% if #title %>
<title><%= #title %></title>
<% elsif content_for?(:title) %>
<title><%= yield(:title) %></title>
<% else %>
<title><%= t(:stocktaking_title) %></title>
<% end %>
You could condense this into a ternary but the view wouldn't be very readable.
If you insist on using content_for inside of the controller, you can use the view_context method, but you can't seem to work with content_for directly like so:
view_context.content_for(:title, "My Awesome Title")
Instead, you'll need to implement your own content_for method to extend off of the view_context. I pulled it from this Gist, but here's the code:
class ApplicationController < ActionController::Base
...
# FORCE to implement content_for in controller
def view_context
super.tap do |view|
(#_content_for || {}).each do |name,content|
view.content_for name, content
end
end
end
def content_for(name, content) # no blocks allowed yet
#_content_for ||= {}
if #_content_for[name].respond_to?(:<<)
#_content_for[name] << content
else
#_content_for[name] = content
end
end
def content_for?(name)
#_content_for[name].present?
end
end
This has been tested and works.
Then just do content_for :title, "My Awesome Title" in your controller.
Seriously though, using #title will be way way easier and less "hacky." You could even do something cool like this:
<title><%= #title || content_for(:title) || t(:stocktaking_title) %></title>