Rails 7.2 allow_browser version guard feature

This lesson is from Your browser is not supported. Please upgrade your browser to continue.
In your Rails server logs, you will see:

Rendering public/406-unsupported-browser.html


Completed 406 Not Acceptable

The Rails server is returning a 406 Not Acceptable HTTP code response due to a new feature that allows you to specify which browsers can access your site.

The allowed versions are specified in ApplicationController with the allow_browser method. 

CODE Kopieren

class ApplicationController < ActionController::Base

  # Only allow modern browsers supporting webp images, web push, 

  # badges, import maps, CSS nesting, and CSS :has.



  allow_browser versions: :modern

end

The default value is set to :modern which refers to the following versions:

CODE Kopieren

{ modern: 

  {

    safari: 17.2,

    chrome: 120,

    firefox: 121,

    opera: 106,

    ie: false

  }

}

These versions are from December 2023.

You can specify minimum versions for any browser and also whether they apply to all actions or some, using only and except. You can specify versions in ApplicationController and also in individual controllers for finer control.

For example, to allow all versions of Chrome and Opera, no versions of "internet explorer" (ie), Safari versions 16.4+ and Firefox 121+:

CODE Kopieren

allow_browser versions: { safari: 16.4, firefox: 121, ie: false }

To block specific versions for specific controller actions, in addition to those specified in ApplicationController:

CODE Kopieren

class ProductsController < ApplicationController

  allow_browser versions: { opera: 105, chrome: 119 }, only: :show

end

You can allow all versions by deleting or commenting out the allow_browser line.

Learn to build production apps with Ruby on Rails.