Question

Can someone help me understand how to make Ryan Bate’s screencast on Backbone.js work with MongoDB as my database while using the Mongoid gem.

This is what I am seeing.

When I create a new entry via the console, similar to how Ryan did it in the video with entry.create, Rails adds that entry just fine. Below is my Ruby log and my JavaScript headers log from Chrome Inspector.

Ruby Log

Started POST "/api/entries" for 127.0.0.1 at 2012-02-12 17:31:24 -0600
Processing by EntriesController#create as JSON
Parameters: {"name"=>"Heather", "entry"=>{"name"=>"Heather", "action"=>"create",         "controller"=>"entries"}}
MONGODB w_market_development['system.namespaces'].find({})
MONGODB           w_market_development['entries'].insert([{"_id"=>BSON::ObjectId('4f384bcc504b9348be000003'),     "name"=>"Heather"}])
Completed 201 Created in 11ms (Views: 2.4ms)

Headers Log

Request URL:http://0.0.0.0:3000/api/entries
Request Method:POST
Status Code:201 Created
Request Headers (14)
Request Payload
{"name":"Heather"}

As you can see it posted fine. Now let me show you an update via the entry.save() example Ryan showed us.

Ruby Log

Started POST "/api/entries" for 127.0.0.1 at 2012-02-12 17:34:25 -0600
Processing by EntriesController#create as JSON
Parameters: {"_id"=>"4f38152c504b9345dc000005", "name"=>"Bloip", "winner"=>true,     "entry"=>{"_id"=>"4f38152c504b9345dc000005", "name"=>"Bloip", "winner"=>true,     "action"=>"create", "controller"=>"entries"}}
MONGODB w_market_development['system.namespaces'].find({})
MONGODB     w_market_development['entries'].insert([{"_id"=>BSON::ObjectId('4f38152c504b9345dc000005'),     "name"=>"Bloip", "winner"=>true}])
Completed 201 Created in 12ms (Views: 2.7ms)

Headers Log

Request URL:http://0.0.0.0:3000/api/entries
Request Method:POST
Status Code:201 Created
Request Headers (14)
Request Payload
{"_id":"4f38152c504b9345dc000005","name":"Bloip","winner":true}

---

As you can see when I complete the entry.save() on a current entry, which should be an update, the JSON is showing a POST instead of a PUT, which Mongoid is doing nothing with and the DB shows no changes. After Googling I found the following articles but nothing really helped.

https://github.com/codebrew/backbone-rails/issues/8
http://lostechies.com/derickbailey/2011/06/17/making-mongoid-play-nice-with-backbone-js/

Answer 1

When I was going through the RailsCast as described above. I was using the entries controller that Ryan put together. After much searching, copying, pasting, and retrying I found that I need a completely new Controller set up. Below is what I originally had.

class EntriesController < ApplicationController
  respond_to :json

  def index
    respond_with Entry.all
  end

  def show
    respond_with Entry.find(params[:id])
  end

  def create
    respond_with Entry.create(params[:entry])
  end

  def update
    respond_with Entry.update(params[:id], params[:entry])
  end

  def destroy
    respond_with Entry.destroy(params[:id])
  end
end

This is the Controller code the fixed the issue for me.

class EntriesController < ApplicationController
  def index
      render :json => Entry.all
    end

    def show
      render :json => Entry.find(params[:id])
    end

    def create
      entry = Entry.create! params
      render :json => entry
    end

    def update
      entry = Entry.find(params[:id])
      entry.update_attributes!(params[:entry])
      render :json => entry
    end

    def destroy
      render :json => Entry.destroy(params[:id])
    end
  end

Thanks All!

Travis