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Rails

https://rubyonrails.org/

Reference repo - https://github.com/munderseth/my.rails

To create an example app:

rails new .

Options:

  • -T - no tests
  • -d mysql - use MySQL

To force a reinstall of all gems:

bundle install --force

Development​

Terms​

  • CRUD - Create, Read, Update, Destore
  • MVC - Model (db), View (pages), Controller (logic)
  • erb - Embedded Ruby (template code within html)
  • Capybara (ca.pa.bar.a) -

MVC​

The model-view-controller (MVC) pattern

Model-View-Controller

CRUD​

Web applications involve CRUD - Create, Read, Update, and Delete - operations. Rails uses the term resource to represent a collection of routes, along with controller actions and views that perform CRUD on a database model (i.e. data).

A method called resource that creates conventional routes and helper methods.

Example for an Article model:

Prefix Verb   URI Pattern                  Controller#Action
        root GET    /                            articles#index
    articles GET    /articles(.:format)          articles#index
 new_article GET    /articles/new(.:format)      articles#new
     article GET    /articles/:id(.:format)      articles#show
             POST   /articles(.:format)          articles#create
edit_article GET    /articles/:id/edit(.:format) articles#edit
             PATCH  /articles/:id(.:format)      articles#update
             DELETE /articles/:id(.:format)      articles#destroy

In addition, article_path and article_url are created.

Notes:

  • Validations are rules that are checked before a model object is saved.

Database​

Drop:

bundle exec rake db:drop

Create:

bundle exec rake db:create db:migrate

Commands​

  • rails console
  • rails routes --expanded - list all of the routes (refer here)
  • rails generate rspec:install - setup rspec within project
  • irb - ruby interpreter
  • gem which <name> - shows gem location
  • whereis <bin> - linux command to show location
  • Add to log file - logger.debug "This is a debug message"

Debugging​

logger.debug "DEBUG: #{__method__}, #{__FILE__}:#{__LINE__}"

Testing​

Setup​

  1. Update Gemfile
    gem "rspec-rails"
    gem "capybara"
    gem "selenium-webdriver"
    gem "factory_bot_rails"
    gem "database_cleaner"
  2. Bundle install
  3. Create spec/support/factory_bot.rb
    RSpec.configure do |config|
        config.include FactoryBot::Syntax::Methods
    end
  4. Uncomment "Dir[Rails.root.join].." in spec/rails_helper.rb

References​

Codespaces​

There are some specific to work in Codespaces.

Requires to install rails:

gem install rails

In the controllers required to add the following before a POST (Create):

skip_before_action :verify_authenticity_token

Otherwise will not write to the database. Refer to stackoverflow question for more details.

References​