Query Objects without a hitch.

Hayrick lets you easily create Query Objects, decoupling your data models from querying concerns. It is extremely lightweight, having less than 100 lines of code and no external dependencies. Hayrick currently supports Active Record and Sequel.

First, add this line to your application's Gemfile:

gem 'hayrick'

Then you have just to include the Hayrick module and implement a #base_scope method:

class AlbumCollection
  include Hayrick

  def base_scope
    Album.all # or Album.unscoped depending on your Rails version
  end
end

And that's it! You're now able to perform queries by calling AlbumCollection#search.

AlbumCollection.new.search(artist: 'Morphine')
=> #<ActiveRecord::Relation [#<Album id: 1, name: "Good", artist: "Morphine", release_date: "1992-09-08">, #<Album id: 2, name: "Cure for Pain", artist: "Morphine", release_date: "1993-09-14">...]>

That seems fine, but we usually want to carry out queries using parameters other than our model fields, right? Hayrick provides a simple DSL for adding such filters:

class AlbumCollection
  include Hayrick

  filter :year do |search_relation, year|
    search_relation.where('extract(year from released_at) = ?', year)
  end

  def base_scope
    Album.all
  end
end

Notice the .filter method receives two parameters:

• a filter name (in this case, :year)
• a filter definition which can be either a Proc or a block. This callable object must receive two arguments: the first is the search relation and the second is the argument for the filter itself. Make sure to always return the search relation to prevent the filter chain from breaking.

AlbumCollection.new.search(artist: 'Morphine', year: 1993)
=> #<ActiveRecord::Relation [#<Album id: 2, name: "Cure for Pain", artist: "Morphine", release_date: "1993-09-14">]>