Module: ActionController::AllowBrowser::ClassMethods

Defined in:
lib/action_controller/metal/allow_browser.rb

Instance Method Summary collapse

Instance Method Details

#allow_browser(versions:, block: -> { render file: Rails.root.join("public/406-unsupported-browser.html"), layout: false, status: :not_acceptable }, **options) ⇒ Object

Specify the browser versions that will be allowed to access all actions (or some, as limited by ‘only:` or `except:`). Only browsers matched in the hash or named set passed to `versions:` will be blocked if they’re below the versions specified. This means that all other browsers, as well as agents that aren’t reporting a user-agent header, will be allowed access.

A browser that’s blocked will by default be served the file in public/406-unsupported-browser.html with a HTTP status code of “406 Not Acceptable”.

In addition to specifically named browser versions, you can also pass ‘:modern` as the set to restrict support to browsers natively supporting webp images, web push, badges, import maps, CSS nesting, and CSS :has. This includes Safari 17.2+, Chrome 120+, Firefox 121+, Opera 106+.

You can use caniuse.com to check for browser versions supporting the features you use.

You can use ‘ActiveSupport::Notifications` to subscribe to events of browsers being blocked using the `browser_block.action_controller` event name.

Examples:

class ApplicationController < ActionController::Base
  # Allow only browsers natively supporting webp images, web push, badges, import maps, CSS nesting, and CSS :has
  allow_browser versions: :modern
end

class ApplicationController < ActionController::Base
  # Allow only browsers natively supporting webp images, web push, badges, import maps, CSS nesting, and CSS :has
  allow_browser versions: :modern, block: :handle_outdated_browser

  private
    def handle_outdated_browser
      render file: Rails.root.join("public/custom-error.html"), status: :not_acceptable
    end
end

class ApplicationController < ActionController::Base
  # All versions of Chrome and Opera will be allowed, but no versions of "internet explorer" (ie). Safari needs to be 16.4+ and Firefox 121+.
  allow_browser versions: { safari: 16.4, firefox: 121, ie: false }
end

class MessagesController < ApplicationController
  # In addition to the browsers blocked by ApplicationController, also block Opera below 104 and Chrome below 119 for the show action.
  allow_browser versions: { opera: 104, chrome: 119 }, only: :show
end



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# File 'lib/action_controller/metal/allow_browser.rb', line 57

def allow_browser(versions:, block: -> { render file: Rails.root.join("public/406-unsupported-browser.html"), layout: false, status: :not_acceptable }, **options)
  before_action -> { allow_browser(versions: versions, block: block) }, **options
end