ScopieRails

Scopie for Rails

ScopieRails allows you to map incoming controller parameters to named scopes in your resources and decouple mapping logic from controller. ScopieRails is the yet another implementation of has_scope. The key difference is dedicated class where the scopes are defined. To override default mapping behavior you don't need to pass a block - just define a method with the same name as scope. You can DRY your custom scopes mapping logic by using helper methods defined in scopie class and use the same scopie class in multiple controllers.

Imagine the following model called graduations:

class Graduation < ActiveRecord::Base
  scope :featured, -> { where(featured: true) }
  scope :by_degree, -> (degree) { where(degree: degree) }
  scope :by_period, -> (started_at, ended_at) { where('started_at = ? AND ended_at = ?', started_at, ended_at) }
end

You can use those named scopes as filters by declaring them on your scopie:

class Scopies::GraduationsScopie < ScopieRails::Base
  has_scope :featured, type: :boolean
  has_scope :by_degree, :by_period
  has_scope :page, default: 1
  has_scope :per, default: 30

  def by_period(scope, value, _hash)
    scope.by_period(value[:started_at], value[:ended_at])
  end
end

Now, if you want to apply them to an specific resource, you just need to call apply_scopes:

class GraduationsController < ApplicationController
  include ScopieRails::Controller

  def index
    @graduations = apply_scopes(Graduation).all
  end
end

Then for each request:

/graduations
#=> acts like a normal request

/graduations?featured=true
#=> calls the named scope and bring featured graduations

/graduations?by_period[started_at]=20100701&by_period[ended_at]=20101013
#=> brings graduations in the given period

/graduations?featured=true&by_degree=phd
#=> brings featured graduations with phd degree

Installation

Add scopie_rails to your Gemfile or install it from Rubygems.

gem 'scopie_rails'

Options

Scopie supports several options:

• :type - Coerces the type of the parameter sent.

• :only - In which actions the scope is applied.

• :except - In which actions the scope is not applied.

• :as - The key in the params hash expected to find the scope. Defaults to the scope name.

• :in - The key in the params hash expected to contain a hash holding scope name as a value.

• :allow_blank - Blank values are not sent to scopes by default. Set to true to overwrite.

• :default - Default value for the scope. Whenever supplied the scope is always called.

Rails

ScopieRails provides Rails integration for Scopie.

Among other things it adds a 'controller' method to scopies.

Thanks

Scopie was inspired by has_scope and pundit.

Thanks to both.