README

Initial setup

To create api call

$ rails new api_name --api

After adding gems in the Gemfile. they can be fetched using

$ bundle install

Models

To create a model

$ rails g scaffold User name:string

Reference model

To create a model that belongs to another model

$ rails g scaffold Post user:references title:text body:text

a model can have multiple references

It's possible to create a one to many relationship by adding has_many to the model.

Database

To create the database:

$ rake db:create

To migrate database:

$ rake db:migrate

To feed database with dev data

$ rake db:seed

If a db change is needed a migration can be created using

$ rails g migration change_something_to_be_something_else

The migration file might resemble this

class ChangeSomethingToBeSomethingElse < ActiveRecord::Migration[5.0]
  def change
    change_column :customers, :phone, :string
  end
end

for a rollback enabled migration it's possible to use up/down instead of change to be used with db:migrate and db:rollback.

Routes

Under config/routes.rb is a list of exposed http routes

Service Objects

Service Objects are reusable controllers, every Service Object deals with a single concern and performs a specific job. A gem like simple_command can be used for this matter.

Accessors

attr_accessor: creates both reader and writer
attr_reader: creates reader only
attr_writer: creates writer only

can be used as follows

attr_reader :some_attr

Filters

Filters are methods that are run before, after or around a controller action. They are inherited so if a filter is set on the ApplicationController level it will run on every controller in the application.

Example of filters before_action, after_action, around_action which uses two methods before(contorller) and after(controller)

The before filter may halt the request cycle, or redirect to a different workflow.

Filters can be skipped by controllers using skip_before_action, skip_after_action and skip_around_action

A use-case of filters is to make sure a user is authenticated

metallious / rails_tutorial