alininja

Transactions

As your business logic gets complex you may need to implement transactions. The classic example is a bank funds transfer from account A to account B. If the withdrawal from account A fails then the deposit to account B should either never take place or be rolled back.

Basics

All the complexity is handled by ActiveRecord::Transactions. Any model class or instance has a method named .transaction. When called and passed a block, that block will be executed inside a database transaction. If there's an exception raised, the transaction will automatically be rolled back.

	class API::V1::BaseController < ApplicationController

	skip_before_filter :verify_authenticity_token

	before_filter :cors_preflight_check
	after_filter :cors_set_access_control_headers

	def cors_set_access_control_headers
	headers['Access-Control-Allow-Origin'] = '*'
	headers['Access-Control-Allow-Methods'] = 'POST, GET, PUT, DELETE, OPTIONS'

	((context, $) ->
	# COOL WIDGET CLASS DEFINITION
	#===================================
	context = (element, options) ->
	@options = options
	@$element = $(element).on('change', 'input[type=checkbox]', $.proxy(@update, this))

	context:: =
	constructor: context
	update: ->

	#Model

	@user.should have(1).error_on(:username) # Checks whether there is an error in username
	@user.errors[:username].should include("can't be blank") # check for the error message

	#Rendering
	response.should render_template(:index)

	#Redirecting
	response.should redirect_to(movies_path)

	Copyright the authors of Honcho and/or Ben Lopatin

	Licensed for reuse, modification, and distribution under the terms of the MIT license

alininja

Transactions

Basics

Example