Question

I’m using Inherited Resources for my Rails 2.3 web service app.
It’s a great library which is part of Rails 3.

I’m trying to figure out the best practice for outputting the result.

class Api::ItemsController < InheritedResources::Base
  respond_to :xml, :json
  def create
    @error = nil 
    @error = not_authorized if !@user
    @error = not_enough_data("item") if params[:item].nil? 

    @item = Item.new(params[:item])
    @item.user_id = @user.id
    if !@item.save
      @error = validation_error(@item.errors)
    end 
    if !@error.nil?
      respond_with(@error)
    else 
      respond_with(@swarm)
    end 
  end

end

It works well when the request is successful. However, when there’s any error, I get a “Template is missing” error. @error is basically a hash of message and status, e.g. {:message => "Not authorized", :status => 401}. It seems respond_with only calls to_xml or to_json with the particular model the controller is associated with.

What is an elegant way to handle this?
I want to avoid creating a template file for each action and each format (create.xml.erb and create.json.erb in this case)

Basically I want:

/create.json [POST] => {"name": "my name", "id":1}  # when successful 
/create.json [POST] => {"message" => "Not authorized", "status" => 401} # when not authorized

Thanks in advance.

Answer 1

Few things before we start:

• First off. This is Ruby. You know there’s an unless command. You can stop doing if !
• Also, you don’t have to do the double negative of if !*.nil? – Do if *.present?
• You do not need to initiate a variable by making it nil. Unless you are setting it in a before_chain, which you would just be overwriting it in future calls anyway.

What you will want to do is use the render :json method. Check the API but it looks something like this:

render :json => { :success => true, :user => @user.to_json(:only => [:name]) }