This post originated from an RSS feed registered with Ruby Buzz by rwdaigle. Original Post: What's New in Edge Rails: Around Filters are Here Feed Title: Ryan's Scraps Feed URL: http://feeds.feedburner.com/RyansScraps Feed Description: Ryan Daigle's various technically inclined rants along w/ the "What's new in Edge Rails" series. Latest Ruby Buzz Posts Latest Ruby Buzz Posts by rwdaigle Latest Posts From Ryan's Scraps

I’ve mentioned the Meantime filter plugin by Roman Le Negrate in the past as a very useful little utility – apparently the core team agrees as around filtering is now part of edge Rails.

Usage is pretty much the same as with meantime:

class AssetController < ActionController

  before_filter :verify_login
  around_filter :scope_to_owner

  def assets
    @assets = Asset.find(:all)
  end

  def scope_to_owner
    Asset.with_scope({
      :find => { :conditions => [ 'user_id = ?', @user.id ]},
      :create => { :user => @user }
    }) { yield }
  end

end

You can also define a class to handle your filtering needs (whose filter method yields to the action block)

class AssetController < ActionController

  around_filter ScopeFilter   # or ScopeFilter.new
  ...
end

class ScopeFilter
  def filter
    Asset.with_scope({
      :find => { :conditions => [ 'user_id = ?', params[:user_id]},
      :create => { :user_id => params[:user_id] }
    }) { yield }
  end
end

Or you can directly pass a Proc in as the filter:

class AssetController < ActionController

  around_filter (:only => :assets) do |controller,action_block| 
    Asset.with_scope({
      :find => { :conditions => [ 'user_id = ?', params[:user_id]},
      :create => { :user_id => params[:user_id] }
    }) { action_block.call }
    end
  end
  ...
end

Since the around filter explicitly governs the execution of the action being requested, you can use them to skip the action completely. This would act the same as a before_filter that returned false.

tags: rubyonrails, rails