Ruby-on-rails – Rails layouts per action

ruby-on-rails

I use a different layout for some actions (mostly for the new action in most of the controllers).

I am wondering what the best way to specify the layout would be? (I am using 3 or more different layouts in the same controller)

I don't like using

render :layout => 'name'

I liked doing

layout 'name', :only => [:new]

But I can't use that to specify 2 or more different layouts.

For example:

When I call layout 2 times in the same controller, with different layout names and different only options, the first one gets ignored – those actions don't display in the layout I specified.

Note: I'm using Rails 2.

Best Answer

You can use a method to set the layout.

class MyController < ApplicationController
  layout :resolve_layout

  # ...

  private

  def resolve_layout
    case action_name
    when "new", "create"
      "some_layout"
    when "index"
      "other_layout"
    else
      "application"
    end
  end
end

Related Solutions

Ruby-on-rails – Fully custom validation error message with Rails

Now, the accepted way to set the humanized names and custom error messages is to use locales.

# config/locales/en.yml
en:
  activerecord:
    attributes:
      user:
        email: "E-mail address"
    errors:
      models:
        user:
          attributes:
            email:
              blank: "is required"

Now the humanized name and the presence validation message for the "email" attribute have been changed.

Validation messages can be set for a specific model+attribute, model, attribute, or globally.

Ruby-on-rails – Understanding the Rails Authenticity Token

What happens

When the user views a form to create, update, or destroy a resource, the Rails app creates a random authenticity_token, stores this token in the session, and places it in a hidden field in the form. When the user submits the form, Rails looks for the authenticity_token, compares it to the one stored in the session, and if they match the request is allowed to continue.

Why it happens

Since the authenticity token is stored in the session, the client cannot know its value. This prevents people from submitting forms to a Rails app without viewing the form within that app itself. Imagine that you are using service A, you logged into the service and everything is ok. Now imagine that you went to use service B, and you saw a picture you like, and pressed on the picture to view a larger size of it. Now, if some evil code was there at service B, it might send a request to service A (which you are logged into), and ask to delete your account, by sending a request to http://serviceA.com/close_account. This is what is known as CSRF (Cross Site Request Forgery).

If service A is using authenticity tokens, this attack vector is no longer applicable, since the request from service B would not contain the correct authenticity token, and will not be allowed to continue.

API docs describes details about meta tag:

CSRF protection is turned on with the protect_from_forgery method, which checks the token and resets the session if it doesn't match what was expected. A call to this method is generated for new Rails applications by default. The token parameter is named authenticity_token by default. The name and value of this token must be added to every layout that renders forms by including csrf_meta_tags in the HTML head.

Notes

Keep in mind, Rails only verifies not idempotent methods (POST, PUT/PATCH and DELETE). GET request are not checked for authenticity token. Why? because the HTTP specification states that GET requests is idempotent and should not create, alter, or destroy resources at the server, and the request should be idempotent (if you run the same command multiple times, you should get the same result every time).

Also the real implementation is a bit more complicated as defined in the beginning, ensuring better security. Rails does not issue the same stored token with every form. Neither does it generate and store a different token every time. It generates and stores a cryptographic hash in a session and issues new cryptographic tokens, which can be matched against the stored one, every time a page is rendered. See request_forgery_protection.rb.

Lessons

Use authenticity_token to protect your not idempotent methods (POST, PUT/PATCH, and DELETE). Also make sure not to allow any GET requests that could potentially modify resources on the server.

EDIT: Check the comment by @erturne regarding GET requests being idempotent. He explains it in a better way than I have done here.

Best Answer

Related Solutions

Ruby-on-rails – Fully custom validation error message with Rails

Ruby-on-rails – Understanding the Rails Authenticity Token

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