Chris Flipse cflipse

Exposing an API

APIs are becoming an essential feature of modern web applications. Rails does a good job of helping your application provide an API using the same MVC structure you're accustomed to.

In the Controller

Let's work with the following example controller:

class ArticlesController &lt; ApplicationController

Handling Parameters

The controller's job is to work with the request parameters and determine how to activate the domain logic and data to respond to requests. The parameters are key to completing that job.

And, at the same time, parameters are the cause of the most problems in a typical controller. A great action method should be about eight lines of Ruby, but many actions spiral out of control with all kinds of switching based on the input parameters.

`params` Helper

First, a small point of order: people commonly refer to params as a variable but it isn't -- it is a helper method provided by ActionController which returns a hash containing the request parameters.

Instrument Anything in Rails 3

With Rails 3.0 released a few weeks ago I've migrated a few apps and I'm constantly finding useful new improvements. One such improvement is the ability to log anything in the same way that Rails internally logs ActiveRecord and ActionView. By default Rails 3 logs look slightly spiffier than those produced by Rails 2.3: (notice the second line has been cleaned up)

Started GET "/" for 127.0.0.1 at Mon Sep 06 01:07:11 -0400 2010
  Processing by HomeController#index as HTML
  User Load (0.2ms)  SELECT `users`.* FROM `users` WHERE (`users`.`id` = 3) LIMIT 1
  CACHE (0.0ms)  SELECT `users`.* FROM `users` WHERE (`users`.`id` = 3) LIMIT 1

Rendered layouts/_nav.html.erb (363.4ms)

	class GithubService
	Leadlight.build_service(self) do
	url 'https://api.github.com'

	build_connection do \|c\|
	c.adapter :typhoeus
	end

	tint 'root' do
	match_path('/')

	# in spec/spec_helper.rb, add this to make it work:
	# require 'support/be_allowed_to'
	# RSpec.configure \|config\|
	# config.include(BeAllowedToMatcher)
	# end
	#
	# allows: some_user.should be_allowed_to(:edit, thing)
	# some_user.should be_allowed_to(:edit, :things)
	# some_user.should be_allowed_to(:edit, thing, in_this_context)
	# along with the should_not variants

	var reviewGrid = Ext.create("ReviewGrid", {renderTo: 'review'});
	var productStore = Ext.create("ProductStore", {});
	var productForm = Ext.create("ProductForm", {store:productStore, renderTo: 'product', reviewGrid: reviewGrid});

	describe("ProductForm", function() {

	it("should be able to navigate 1 product forward ", function() {
	waitsFor(5000, function () {
	return ( productStore.isLoading() == false);
	}, "productStore load");

	## conduce - be conducive to; "The use of computers in the classroom lead to better writing"
	#
	# a model+view component for rails that combines the conductor and presenter
	# pattern via a model capable of generating view-centric methods
	#


	module Conducer
	# base class
	#


	# session is not preserved between requests in integration tests (since 2.3.8)
	# https://rails.lighthouseapp.com/projects/8994/tickets/4941-session-is-not-preserved-between-requests-in-integration-tests

	# this monkey-fix deals with the issue and is based on the provided patch from
	# the above ticket. require in your test_helper or integration_test_helper ...

	require 'action_controller/session/abstract_store'

	module ActionController

	Just in case you still think bundle sucks, consider the alternative
	This is me getting my blog, a very small Rails 2.3 app with only a few dependencies,
	Up and running on my local machine
	PAINFUL!

	~/dev $ git clone paulbarry.com:paulbarry.git
	Cloning into paulbarry...
	remote: Counting objects: 1408, done.
	remote: Compressing objects: 100% (1071/1071), done.
	remote: Total 1408 (delta 274), reused 1285 (delta 207)