ERB (with Rails)

Intro to ERB

• “Embedded Ruby”
• One of a class of ‘template languages’
• There are many
• They do a simple job (used to be called “mail merge”)

What it does

• Erb file without any `` blocks remains unchanged
• `` must contain legal ruby code
• Let’s look at ErbDemo
• The code between the angle brackets is evaluated.
• *And only in the case of `` it’s inserted into the resulting text

How it works with Rails

• ERBs are used primarily in views (also known as view templates in rails)
• Rails has numerous “helper” methods that work very nicely with erb
• In “routes.rb”: resource or get or path or other command “automatically” defines one or more helpers.
• In the example below, “sessions_path” was generated by the resources :sessions line in routes.rb
• ** Reference:** Rails Form Helpers

Example

  <% form_for(:sessions, url: sessions_path) do |f|  %>
      <div>
        email: <%= f.text_field :email %>
      </div>
      <div>
        password: <%= f.password_field :password %>
      </div>
      <%= f.submit "Sign in" %>
  <% end %>