ruby-on-rails-integration.md

Flexirest: Ruby on Rails Integration

The author built Flexirest to use within Ruby on Rails, but it doesn't require full Ruby on Rails. This guide was tested with a Rails 4.2.x Application but also works fine with Rails 5.x.

Integration

Start referencing flexirest in your Gemfile

# Gemfile
gem 'flexirest'

Configuration

It's possible to explicit specify the base_url in the model class. If you have an common API Endpoint it makes sense to setup an initializer in config/initializers or use the Rails.configuration.x namespace.

This example use a custom file in config/initializers to setup the API endpoint. Either set a fixed URL or use environment variables if you would like to follow the 12factor rules for preparing your application running on cloud infrastructure like Heroku, Kubernetes or Docker Swarm.

# config/initializers/flexirest.rb
Flexirest::Base.base_url = ENV.fetch("API_ENDPOINT_URL")

Routes

Like every other RESTful resource, just add the controller as a reference into your routes.

# config/routes.rb

Rails.application.routes.draw do
  # ...
  resources :people
end

Model

The ActiveModel shortcuts will add support for form_for helper and @person.errors functionally in your views. For example, if you have a scaffolded view structure this will just work out of the box.

Read more about ActiveModel here:

• ActiveModel::Naming
• ActiveModel::Conversion
• ActiveModel::Validations

In Rails, a resourceful route provides a mapping between HTTP verbs and URLs to controller actions.

Add the GET, POST, PATCH and DELETE methods that reflect to your endpoint.

Add the persisted? method to your Class to support Rails' named_routes, so you could use edit_person_path(person) without explicitly passing the person.id.

# app/models/person.rb
class Person < Flexirest::Base

  extend ActiveModel::Naming
  include ActiveModel::Conversion
  include ActiveModel::Validations

  get    :all,     "/people"
  get    :find,    "/people/:id"
  patch  :update,  "/people/:id"
  post   :save,    "/people"
  delete :destroy, "/people/:id"

  def persisted?
    id.present?
  end

end

Controller

The Controller is structured like an standard RESTful Rails Controller. Only the update method has a small change about how params getting processed.

Flexirest requires the id inside the params hash, this is not included by default. Easily merge the current id into the parameters with person_params.merge(id: @person.id)

No other changes had to be made for the controller.

# app/controller/people_controller.rb
class PeopleController < ApplicationController
  before_action :set_person, only: [:show, :edit, :update, :destroy]

  def index
    @people = Person.all
  end

  def show
  end

  def new
    @person = Person.new
  end

  def edit
  end

  def create
    @person = Person.new(person_params)

    if @person.save
      redirect_to @person, notice: 'Person was successfully created.'
    else
      render :new
    end
  end

  def update
    if @person.update(person_params.merge(id: @person.id))
      redirect_to @person, notice: 'Person was successfully updated.'
    else
      render :edit
    end
  end

  def destroy
    @person.destroy
    redirect_to people_url, notice: 'Person was successfully destroyed.'
  end

  private
    # Use callbacks to share common setup or constraints between actions.
    def set_person
      @person = Person.find(params[:id])
    end

    # Never trust parameters from the scary internet, only allow the white list through.
    def person_params
      params.require(:person).permit(:title, :first_name, :last_name, :email)
    end
end

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