Question

The respond_with accepts some parameters, e.g. respond_with(@resource, methods: [:method])
These options should be used in every action. So instead of putting it into every method by hand, is there a possibility to set some default options for just this controller?

Answer 1

The easy and customizable way to do this is by creating a new response method that wraps responds_with.

For example:

class ResourcesController < ApplicationController

  def index
    @resources = Resource.all

    custom_respond_with @resources
  end

private

  def custom_respond_with(data, options={})
    options.reverse_merge!({
      # Put your default options here
      :methods => [ :method ],
      :callback => params[:callback]
    })
    respond_with data, options
  end
end

You could, of course, also overwrite the respond_with completely, however, I find it to be much clearer in the code if you change the name of the method. It also will allow you to use a custom_respond_with in most actions but the standard respond_with in one or two if necessary.

Taking this one step further, if you move the custom_respond_with method to the ApplicationController, you can use it in all of your controllers as necessary.

If you want to specify different default options on a per controller basis, you can do so easily:

class ResourcesController < ApplicationController

  def index
    custom_respond_with Resource.all
  end

private

  def custom_respond_options
    { :methods => [ :method ] }
  end

end

class ApplicationController < ActionController::Base

protected

  def default_custom_respond_options
    {}
  end      

  def custom_respond_with(data, options={})
    options.reverse_merge! default_custom_respond_options
    respond_with data, options
  end

end