Module: ActionController::RecordIdentifier

Extended by:
RecordIdentifier
Included in:
RecordIdentifier, ActionView::Helpers::RecordTagHelper, ActionView::TestCase::Behavior
Defined in:
actionpack/lib/action_controller/record_identifier.rb

Overview

The record identifier encapsulates a number of naming conventions for dealing with records, like Active Records or Active Resources or pretty much any other model type that has an id. These patterns are then used to try elevate the view actions to a higher logical level. Example:

# routes
resources :posts

# view
<%= div_for(post) do %>    <div id="post_45" class="post">
  <%= post.body %>           What a wonderful world!
<% end %>                  </div>

# controller
def destroy
  post = Post.find(params[:id])
  post.destroy

  respond_to do |format|
    format.html { redirect_to(post) } # Calls polymorphic_url(post) which in turn calls post_url(post)
    format.js do
      # Calls: new Effect.fade('post_45');
      render(:update) { |page| page[post].visual_effect(:fade) }
    end
  end
end

As the example above shows, you can stop caring to a large extent what the actual id of the post is. You just know that one is being assigned and that the subsequent calls in redirect_to and the RJS expect that same naming convention and allows you to write less code if you follow it.

Constant Summary

JOIN =
'_'.freeze
NEW =
'new'.freeze

Instance Method Summary collapse

Instance Method Details

#dom_class(record_or_class, prefix = nil) ⇒ Object

The DOM class convention is to use the singular form of an object or class. Examples:

dom_class(post)   # => "post"
dom_class(Person) # => "person"

If you need to address multiple instances of the same class in the same view, you can prefix the dom_class:

dom_class(post, :edit)   # => "edit_post"
dom_class(Person, :edit) # => "edit_person"


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# File 'actionpack/lib/action_controller/record_identifier.rb', line 48

def dom_class(record_or_class, prefix = nil)
  singular = ActiveModel::Naming.singular(record_or_class)
  prefix ? "#{prefix}#{JOIN}#{singular}" : singular
end

#dom_id(record, prefix = nil) ⇒ Object

The DOM id convention is to use the singular form of an object or class with the id following an underscore. If no id is found, prefix with “new_” instead. Examples:

dom_id(Post.find(45))       # => "post_45"
dom_id(Post.new)            # => "new_post"

If you need to address multiple instances of the same class in the same view, you can prefix the dom_id:

dom_id(Post.find(45), :edit) # => "edit_post_45"


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# File 'actionpack/lib/action_controller/record_identifier.rb', line 62

def dom_id(record, prefix = nil)
  if record_id = record_key_for_dom_id(record)
    "#{dom_class(record, prefix)}#{JOIN}#{record_id}"
  else
    dom_class(record, prefix || NEW)
  end
end