Rails%203%20In%20Action

Serving files through a controller
asset = Asset.find(params[:id])
send_file asset.asset.path, :filename => asset.asset_file_name,
:content_type => asset.asset_content_type
end
end
In this action, you find the Asset object by using the params[:id] the action receives.
Then you use the asset object in combination with the send_file method to send
the file back as a response rather than a view in your application.
The first argument for send_file is the path to the file you’re sending. The next
argument is an options hash used to pass in the filename and content_type options
so the browser receiving the file knows what to call it and what type of file it is.
To route requests to this controller, you need to define a route in your config/
routes.rb file, which you can do with this line:
resources :files
When you run the specs for this controller again using bin/rspec spec/controllers
/files_controller_spec.rb, the first spec passes, but the second one fails:
FilesController users without access cannot access assets in this project
...
Expected response to be a , but was .
The show action doesn’t redirect as this example expects because you’re not doing
any permission checking in your action, which is what this example is all about:
“users without access cannot access assets in this project.” To fix this problem,
check that the user has permission to access this asset’s project by using the CanCan
helpers you used in chapter 8. You can use them in your show action now, as shown in
the following listing.
Listing 9.12 app/controllers/files_controller.rb
def show
asset = Asset.find(params[:id])
if can?(:view, asset.ticket.project)
send_file asset.asset.path, :filename => asset.asset_file_name,
:content_type => asset.asset_content_type
else
flash[:alert] = "The asset you were looking for could not be found."
redirect_to root_path
end
end
Now when you rerun these specs, you’re missing a method:
undefined method 'ticket' for #
This method is a simple belongs_to, which you must define inside the Asset model:
belongs_to :ticket
229