rails 4 use application helpers inside initializers

问题

Is it possible to include / use Application Helper methods inside of an config/initializers/browser_blocker.rb?

I am using the browser gem to detect and block older non modern browsers.

Rails.configuration.middleware.use Browser::Middleware do
    include ApplicationHelper
    redirect_to :controller => 'error', :action => 'browser-upgrade-required' if browser_is_not_supported
end

Helper method I am currently working with:

  # test browser version
  def browser_is_not_supported
    return true unless browser.modern?
    return true if browser.chrome? && browser.version.to_i < ENV['BROWSER_BASE_VERSION_GOOGLE'].to_i
    return true if browser.firefox? && browser.version.to_i < ENV['BROWSER_BASE_VERSION_FIREFOX'].to_i
    return true if browser.safari? && browser.version.to_i < ENV['BROWSER_BASE_VERSION_SAFARI'].to_i
    return true if browser.opera? && browser.version.to_i < ENV['BROWSER_BASE_VERSION_OPERA'].to_i
    return true if browser.ie? && browser.version.to_i < ENV['BROWSER_BASE_VERSION_MSFT'].to_i
  end

回答1:

This is one way to do it:

# lib/browser_util.rb
module BrowserUtil
  def self.supported?(browser)
    # your code ...
  end
end

and wrap that from ApplicationHelper for use in views

module ApplicationHelper
  def is_browser_supported?
    BrowserUtil.supported?(browser)
  end
end

in middleware

Rails.configuration.middleware.use Browser::Middleware do
  unless BrowserUtil.supported?(browser)
    redirect_to :controller => 'error', :action => 'browser-upgrade-required' 
  end
end

UPDATE: it does not need to be in a separate module (BrowserUtil)

module ApplicationHelper
  def self.foo
    "FOO"
  end

  def foo
    ApplicationHelper.foo
  end
end

in middleware use

ApplicationHelper.foo

in views it would use the included method

foo

回答2:

Ofcourse you can but that's bad idea, i agree with that that logic supposed to somewhere in app but sometime you have to deal with it. I am saying this because you can block the request before old_browser request gets it and load rails stack.

Anyway, this is how can you can do it

Rails.configuration.middleware.use Browser::Middleware do
  self.class.send(:include,ApplicationHelper)
   redirect_to :controller => 'error', :action => 'browser-upgrade-required' unless    browser_is_supported?
end

来源：https://stackoverflow.com/questions/23035947/rails-4-use-application-helpers-inside-initializers

标签

ruby-on-rails

ruby

gem

initialization