finder_filter gem released

I’m at the Ruby Hoedown in Huntsville this weekend. Being around so many brilliant geeks encouraged me to release a gem I’ve had sitting in the hopper for several weeks.

finder_filter encapsulates a pattern I find myself using quite frequently in Rails. Namely, looking up an instance variable before an action. For example:

class UsersController < ActionController::Base
  before_filter :find_user, :only => [:show, :edit]
  
  def show
    # do something with @user
  end
  
  def edit
    # do something with @user
  end
  
  def find_user
    @user = User.find(params[:id)
  end
end

Sticking the finder in a before filter keeps the code DRY, but it still takes several lines to do this. finder_filter reduces this to a single line of code:

class UsersController < ActionController::Base
  finder_filter :only => [:show, :edit]
  
  def show; end
  def edit; end
end

There are other options to customize the column and param used in the lookup. Check out the README for full details.

To install the gem as a plugin in your Rails project:

sudo gem install pelargir-finder_filter --source=http://gems.github.com

Then open environment.rb in your Rails app and add the gem as a dependency in your initializer block:

Rails::Initializer.run do |config| 
  config.gem "pelargir-finder_filter"
  ...
end

If you have any comments or suggestions, I’d love to hear from you. Contact me through the finder_filter project on GitHub.