refactoring-notes.md

Refactoring Notes

How I go about refactoring the Bowls app to have a jQuery front-end.

Instead of sending HTTP requests via Rails to fetch and load individual pages, we will send AJAX requests to the server to fetch objects in JavaScript Object Notation (JSON) and append these objects to the page.

Process

Refactor config/routes.rb

Draw routes to change a resource such as:

# config/routes.rb

resources :scraps

to:

# config/routes.rb

get 'scraps', to: 'scraps#index'
get 'scraps/:id', to: 'scraps#show'
post 'scraps/new', to: 'scraps#create'
patch 'scraps/:id', to: 'scraps#update'

After which we won't be loading separate pages, but rather rendering JSON and appending it to one page, /scraps.

Set up the remaining routes for API endpoints.

Update ScrapsController to render JSON

For example in the scraps#index action:

# app/controllers/scraps_controller.rb

def index
  if !@bowl
    @scraps = current_user.scraps.all
  else
    @scraps = @bowl.scraps
  end
end

add render json: @scraps, status: 200 :

# app/controllers/scraps_controller.rb

def index
  if !@bowl
    @scraps = current_user.scraps.all
  else
    @scraps = @bowl.scraps
  end
  render json: @scraps, status: 200
end

to render JSON, not redirect to another page.

For scraps#show add render json: @scrap, status: 200.

Set up ActiveModel::Serializer

To serialize Ruby objects into JSON objects, first add the gem:

# Gemfile

gem 'active_model_serializers'

Then run bundle install.

To generate an ActiveModel::Serializer for Scrap run the generator in your console:

$ rails g serializer scrap

Add scrap attributes to scrap_serializer.rb:

# app/serializers/scrap_serializer.rb

class ScrapSerializer < ActiveModel::Serializer
  attributes :id, :description, :category
end

Restart the Rails server, and navigate to /scraps to see scraps rendered in JSON.

Make an ActiveModel:: Serializer for Bowl:

$ rails g serializer bowl

Create associations by adding has_many :scraps to bowl_serializer.rb:

# app/serializers/bowl_serializer.rb

class BowlSerializer < ActiveModel::Serializer
  attributes :id

  has_many :scraps
end

And has_many :bowls to scrap_serializre.rb:

# app/serializers/scrap_serializer.rb

class ScrapSerializer < ActiveModel::Serializer
  attributes :id, :description, :category

  has_many :bowls
end

Create a BowlScrapSerializer:

$ rails g serializer bowl_scrap

Add the description attribute to and remove the id attribute from this BowlScrapSerializer:

# app/serializers/bowl_scrap_serializer.rb

class BowlScrapSerializer < ActiveModel::Serializer
  attributes :description
end

Explicitly give the BowlSerializer the BowlScrapSerializer when rendering a Scrap:

# app/serializers/bowl_serializer.rb

class BowlSerializer < ActiveModel::Serializer
  attributes :id

  has_many :scraps, serializer: BowlScrapSerializer
end

Configure AMS

Like in this lesson here.

Update Views

---

Resources

I used Markdown Editor and Markdown Cheatsheets [1] [2] to help create this document