Filterable By

ActiveRecord plugin to parse e.g. a filter query parameter apply scopes. Useful for JSON-API compatibility.

Installation

Add gem 'filterable-by' to your Gemfile.

Usage

class Comment < ActiveRecord::Base
  belongs_to :post

  filterable_by :post_id, :user_id
  filterable_by :post_author_id do |scope, value|
    scope.joins(:posts).where(:"posts.author_id" => value)
  end
end

Comment.filter_by(params[:filter])  # => ActiveRecord::Relation

Simple use cases:

Comment.filter_by({ "post_id" => "1" })
# => WHERE post_id = 1

Comment.filter_by({ "user_id" => "2", "ignored" => "3" })
# => WHERE user_id = 2

Comment.filter_by({ "post_author_id" => "5" })
# => JOINS posts ON posts.id = comments.post_id WHERE posts.author_id = 5