Rails - KeynesYouDigIt/Knowledge GitHub Wiki

• rails new [project name] - Create a new project
• rails generate controller [plural controller name] [action names you want to add]

• Decide which controller will handle a request

Rails.application.routes.draw do
  get 'welcome/index' # Send requests for '/welcome/index' to the welcome controller's index action
  root 'welcome#index' # Send requests for root to the welcome controller's index action
  resources :articles # Standard REST action
end

• Collect information for a view
• Collect information with actions
• All instance variables from a controller are passed to rendered views

# calls render with a hash- key is `plain`, `params[:article].inspect` are the article parameters from the form

def create
    render plain: params[:article].inspect
end

def show
    @article = Article.find(params[:id])
end

def create
    @article = Article.new(params[:article])
    if @article.save
        redirect_to @article
    else
        render 'new' # Passes the broken article to the view
    end
end

• Display information from a controller
• Written in ERB templates
• Put in app/views/[plural name]/[action].html.erb
• Have access to router path variables- new_article is availabile at new_article_path
• Use the action name if its in the same controller as the current view, specify controller otherwise

<%= link_to 'Link Text' item_path(item) %>

• Helper ERB method called form_with

# Generates a form with title and text edit areas
# articles_path comes from router, makes a POST request by default
# local: true disables AJAX
<%= form_with scope: :article, url: articles_path, local: true do |form| %>

<p>
    <%= form.label :title %>
    <br />
    <%= form.text_field :title %>
</p>

<p>
    <%= form.label :text %>
    <br />
    <%= form.text_area :text %>
</p>
<p>
    <%= form.submit %>
</p>
<% end %>

• Model name is singular, database table is plural
• rails generate model [Singular name] [property]:[type] [another property]:[type]
• ActiveModel automatically maps DB properties to model properties

# Save model
def create
    # @article = Article.new(params[:article]).permit(:title, :text) # Article refers to the class
    @article = Article.new(article_params)
    @article.save
    redirect_to @article
end

private
    def article_params
        params.require(:article).permit(:title, :text) # Whitelist of allowed properties
    end

• Rake is the task runner
• rails server - Starting built-in Puma server
• rails db:migrate
  • rails db:migrate RAILS_ENV=production

app - Controllers, models, views, helpers, mailers, channels, jobs, and assets bin - Scripts to start, setup, update, deploy, or run the app config - Configure routes and database config.ru - Rack configuration for Rack servers db - DB schema and migrations Gemfile, Gemfile.lock - Dependencies lib - Extended modules log - Log files package.json - npm dependencies public - Delivered as-is Rakefile - CLI tasks, add your own in lib/tasks tests - Unit tests and fixtures vendor - Third-party code .ruby-version - Default ruby version