Instance Public methods
allow_browser(versions:, block: -> { render file: Rails.root.join("public/406-unsupported-browser.html"), layout: false, status: :not_acceptable } Link
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
# 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
# File actionpack/lib/action_controller/metal/allow_browser.rb, line 47 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