Serpentine
Serpentine makes complicated query parameters easy. This is a very commong problem in rails applications. Your controller needs to accept a variety of input parameters to filter/order/search a collection in some way. It's not hard to write this logic, but god damn it is a pain in the ass. It's just a lot of worthless conditional programming. Serpentine makes this easier.
Usage
class PostsController < ApplicationController
filter_collection :alphabetically
filter_collection :by_ids, :if => proc { |params| params[:ids] }
# apply_scopes! is added by Serpentine. You can call it yourself
# in your own actions if you like.
before_filter :apply_scopes!, :only => :index
# define a collection accessor
# It is important to use ||= here
# otherwise Post.unscoped will *always* be passed into
# the next filter
def collection
@collection ||= Post.unscoped
end
def index
respond_with @collection
end
private
# define methods declared in filters
def alphabetically
collection.alphabetically
end
def by_ids
collection.where :id => params[:ids]
end
endMore Examples
class PostsController < ApplicationController
filter_collection :method_name, :if => proc { |params| }
filter_collection :method_name, :if => :name_of_method
filter_collection :method_name, :unless => proc { |params| }
filter_collection :method_name, :unless => :name_of_method
filter_collection :method_name
def collection
@collection ||= Post.unscoped
end
def index
apply_scopes!
# collection now has all the different filters applied
do_more_logic_on collection
respond_with collection
end
endAnd that's it! This will keep the real logic outside of your actions.
This make it trivially easy to add more filters. Filters are
inheritable. You can define filters in ApplicationController and they
will be passed down to all other subclasses.