Comments on: Passing a parameter to a before filter http://blog.aclarke.eu/passing-a-parameter-to-a-before-filter/?utm_source=rss&utm_medium=rss&utm_campaign=passing-a-parameter-to-a-before-filter random thoughts Mon, 26 Dec 2011 07:45:49 +0000 hourly 1 http://wordpress.org/?v=3.3.1 By: andrew http://blog.aclarke.eu/passing-a-parameter-to-a-before-filter/#comment-7 andrew Tue, 20 Jan 2009 17:40:04 +0000 http://blog.aclarke.eu/?p=3#comment-7 Hi Cassiano, I fixed your comment :) Wordpress was obviously screwing up your previous attempts. The parameterized_before_filter is great much more thought out than my simple attempt. I'm not sure why rails doesn't provide such a method already as it is pretty useful, i guess though that ruby lets you do it pretty easily anyway if in a non newbie friendly way. If you find out the reason please let me know. Hi Cassiano,
I fixed your comment :) WordPress was obviously screwing up your previous attempts.
The parameterized_before_filter is great much more thought out than my simple attempt.
I’m not sure why rails doesn’t provide such a method already as it is pretty useful, i guess though that ruby lets you do it pretty easily anyway if in a non newbie friendly way. If you find out the reason please let me know.

]]> By: Cassiano D'Andrea http://blog.aclarke.eu/passing-a-parameter-to-a-before-filter/#comment-3 Cassiano D'Andrea Tue, 20 Jan 2009 17:09:24 +0000 http://blog.aclarke.eu/?p=3#comment-3 Hi. After reading your post I came out with: <pre> class ApplicationController < ActionController::Base ################################################# def self.parameterized_before_filter(filter_name, *args) options = args.extract_options! self.before_filter(options) { |controller| controller.send(filter_name, *args) } end ################################################# # Sample usage with 2 parameters. parameterized_before_filter :my_filter, 'param1', 'param2', :only => :create ################################################# # Sample usage passing a hash as a parameter value. parameterized_before_filter :my_filter, 'param1', 'param2', { :param3 => :value3 }, :only => :create ################################################# # The filter itself. def my_filter(*args) puts args.inspect end end </pre> How do you like it? Why doesn't Rails provide such method out of the box? One might also add :parameterized_before_filter directly to ActionController::Base, or even replace the original :before_filter (using :alias_method_chain). Thanks for sharing the tip. Hi. After reading your post I came out with:

class ApplicationController < ActionController::Base
  #################################################
  def self.parameterized_before_filter(filter_name, *args)
    options = args.extract_options!

    self.before_filter(options) { |controller| controller.send(filter_name, *args) }
  end

  #################################################
  # Sample usage with 2 parameters.
  parameterized_before_filter :my_filter, 'param1', 'param2', :o nly => :create

  #################################################
  # Sample usage passing a hash as a parameter value.
  parameterized_before_filter :my_filter, 'param1', 'param2',
                                            { :param3 => :value3 }, :o nly => :create

  #################################################
  # The filter itself.
  def my_filter(*args)
    puts args.inspect
  end
end

How do you like it? Why doesn’t Rails provide such method out of the box?

One might also add :parameterized_before_filter directly to ActionController::Base, or even replace the original :before_filter (using :alias_method_chain).

Thanks for sharing the tip.

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