Herd
Organize ActiveRecord collection functionality into manageable classes.
Requirements
- Ruby >= 1.9.2
- Rails >= 3.0.0
What is Herd?
As models grow in size and complexity, it can be challenging to keep track of which class methods are for collections and which are not. Throw validations, associations, and scopes into the mix, and the model can become unwieldy to manage.
Herd provides a way to organize collection related functionality into separate, manageable classes.
Take the following ActiveRecord class for example:
class Movie < ActiveRecord::Base
scope :recent, where('released_at > ?', 6.months.ago)
scope :profitable, where('gross > budget')
def self.filter_by_title(title)
where('title LIKE ?', "%#{title}%")
end
def release_year
released_at.year
end
def profitable?
gross > budget
end
end
Using Herd, you can define a separate class to declare collection concerns:
class Movie < ActiveRecord::Base
herded_by Movies
def release_year
released_at.year
end
def profitable?
gross > budget
end
end
class Movies < Herd::Base
model Movie # optional
scope :recent, where('released_at > ?', 6.months.ago)
scope :profitable, where('gross > budget')
def self.filter_by_title(title)
where('title LIKE ?', "%#{title}%")
end
end
Installation
Add this line to your application's Gemfile:
gem 'herd'
And then execute:
$ bundle
Or install it yourself as:
$ gem install herd
Usage Example
Using Herd is as easy as inheriting from Herd::Base
. Declaring the
model is optional if it can be inferred by the ActiveRecord class
name.
class Movie < ActiveRecord::Base
herded_by Movies
has_and_belongs_to_many :directors
has_many :characters, :dependent => :destroy
end
class Movies < Herd::Base
model Movie # optional
scope :failures, where("revenue < '10000000'")
def self.directed_by(director)
where(directors: {name: director}).joins(:directors)
end
end
Then you can use the collection methods as if they were defined in the model class:
Movie.where('released_at < 2012-06-01').failures
Director.first.movies.failures
You can also use the Herd classes directly:
Movies.failures
Contributing
- Fork it
- Create your feature branch (
git checkout -b my-new-feature
) - Commit your changes (
git commit -am 'Added some feature'
) - Push to the branch (
git push origin my-new-feature
) - Create new Pull Request