Sample CoffeeScript AJAX request… //This code fetches data from “/test”, and then appends the result to the div with an id of results… $.ajax(url: “/test”).done (html) -> $(“#results”).append html Unobtrusive JavaScript is separating the script from the HTML markup Built-in helper methods form_for and form_tag … helps in writing forms // Remote submits the form via […]

Associations between models make common operations simpler and easier class Customer < ActiveRecord::Base has_many :orders, dependent: :destroy end class Order < ActiveRecord::Base belongs_to :customer end By declaring that one model belongs_to another, you instruct Rails to maintain Primary Key-Foreign Key information between instances of the two models, and you also get a number of utility […]

Validations are used to ensure that only valid data is saved into your database Model-level validations are the best way They are database agnostic, cannot be bypassed by end users, and are convenient to test and maintain If any validations fail, the object will be marked as invalid and Active Record will not perform the […]

By default, controllers in Rails automatically render views with names that correspond to valid routes The rule is that if you do not explicitly render something at the end of a controller action, Rails will automatically look for the action_name.html.erb template in the controller’s view path and render it If you want to render the […]

Routing connects URLs to code and generates paths from code // routes.rb … e.g. directs a call of /patients/17 to the show action (method) in the patients controller with a parameter of {id: ’17’} … the ‘as’ option names the route, creating the patient_path and patient_url helper methods get ‘/patients/:id’, to: ‘patients#show’, as: ‘patient’ // […]

Sketch Use Cases, Page Flow, & Basic Data Identify basic use cases, sketch page flow on paper (or simple drawing app), and identify basic data (e.g. product which will have a name, description, image, and price) Ambiguity is ok at this stage since Ruby on Rails is great for agile, iterative development Pick a part of […]

Most common relationship types for models One-to-one One-to-many (parent/child relationships) The parent has many children The children belong to a parent Many-to-many A book has many authors An author has many books Create model in the middle so info can be reused A doctor has many patients through appointments Use the resource generator to generate […]

You can also validate any object, not just ActiveRecord objects Declare rules using validation helpers (e.g. validates :title, presence: true … which validates that the title is there) Lifecycle methods – save, update, and create “Bang” method variants raise exception if object is not valid (e.g. save!, create!, update!) include ActiveModel::Validations Validations populate the errors object […]

There’s a default testing framework in Ruby 1.9+ Borrows from Test::Unit and RSpec Choose one or the other to write all your tests in; don’t use both … be consistent Rails provides testing support out of the box Test runner (via Rake) Testing models against the database using fixtures Functional testing controllers (e.g. that the create […]

rails -v to check version Rails takes MVC further: when you develop in Rails, you start with a working application, there’s a place for each piece of code, and all the pieces of your application interact in a standard way Once you create an application with a specific version of Rails, it will continue to use […]

ruby -v to check version Everything in Ruby is an object You don’t declare variable types, but all objects have a type No compiler, so unit testing is crucial No auto type conversion … “3” + 4 results in a TypeError Created in Japan in 1995 by Yukihiro Matsumoto “Mats” Inspired by Pearl and Smalltalk […]