Ruby_Notes.md

Model View Controller (MVC)

From Rails 4 in Action

Model:

• Contain the domain logic of an application, which tell you how records in database are retrieved, validated, or manipulated

Controllers:

• the layer between the users and the database
• Call methods in the model classes
  • from the methods they return single objects or arrays of objects
• Make objects available to the View via instance variables
• Used for permission checking (making sure users who have permission get access, and those who don't, don't get access).

Views:

• Reference instance variables to display information it gets from the controller.
• ERB (Embedded Ruby) is a templating language included in Rails by degault that lets you embed ruby files into any other kind of file, so when users see your application in the View, they are seeing files that have ruby embedded in them.

Directories: Assets, Helpers, Mailers

Assets Directory:

• It's for the standard applications (JS, CSS) that make the app look pretty.p

Helpers Directory:

• Where you put the Ruby code (helper methods and modules) for the Views .

Mailers:

• Where you put the classes of the application that deal with sending emails.

REST

• REST = Representational State Transfer. It's the convention for routing, how requests are routed (e.g. how urls map to the controller, where a form submits data)

Scaffolding & Migrations

Scaffolding:

• Scaffolds are generated to provide temporary structures to get you started on an application
• The scaffold command generates your model, views, and controller, and the tests

Migrations:

• Ruby classes that define a change method
• They inherit from ActiveRecord::Migration

Parameters:

• something_params is a strong parameters method called params, that returns parameters sent from a form or something in your app, in a hash-like object

Namibia Torres