This post originated from an RSS feed registered with Ruby Buzz by Scott Patten. Original Post: Adding json responses to all of your controller actions Feed Title: Scott Patten's Blog Feed URL: http://feeds.feedburner.com/scottpatten.ca Feed Description: Scott Patten is the cofounder of Ruboss (http://ruboss.com) and Leanpub (http://leanpub.com), both based in Vancouver. He is also the author of The S3 Cookbook (http://leanpub.com/thes3cookbook). He blogs about Startups, Ruby, Rails, Javascript, CSS, Amazon Web Services and whatever else strikes his fancy. Latest Ruby Buzz Posts Latest Ruby Buzz Posts by Scott Patten Latest Posts From Scott Patten's Blog

format.json  { render :json => @bookmark }

Now, the easiest way to do this would be to add JSON response to the scaffolding. The templates are in RAILS_ROOT/vendor/rails/lib/rails_generator/generators/components/scaffold/. Open up the controller.rb template and add in the JSON response shown above to the index, show, update and destroy methods and you’re done.

Unfortunately, I had already mostly developed the API when I realized that I had to add in the JSON responses (It’s not Gerald’s fault, he told me long ago). So, I decided to write a quick rake task to do the job for me. To use it, create a file called add_json.rake in RAILS_ROOT/lib/tasks and copy the following code in to it:

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namespace :rails do
  
  desc "Adds a 'format.json ...' line for each 'format.xml ...' line in every controller"
  task :add_json => :get_controller_list do
    @controllers.each do |controller|
      new_lines = File.open(controller, 'r').readlines.collect do |line|
        if line =~ /^\s+format\.xml/
          [line, line.gsub(/xml/, 'json')]
        else
          line
        end
      end.flatten
        
      file = File.open(controller, 'w') do |file|
        file.puts new_lines
      end
    end
  end
  
  task :get_controller_list => :environment do
    @controllers = Dir.glob(File.join(RAILS_ROOT, 'app', 'controllers', '*_controller.rb'))
  end
end

Call the task from RAILS_ROOT like this: rake rails:add_json

The task opens up every controller, and every time it finds a line that starts with format.xml, it makes a copy of that line just below with every instance of ‘xml’ replaced with ‘json’. It’s pretty very brain-dead: it doesn’t check if the json response is already there, so don’t run it twice on the same project.