ActiveFilters

Active Filters allows you to map incoming controller parameters to filter your resources by chaining scopes.

It is inspired by Justin Weiss solution offering a cleaner way to declare your filters.

The gem has_scope exists but does not handle params stored as the value of a hash.

Add this line to your application's Gemfile:

gem 'active_filters'

And then execute:

$ bundle install

Or install it yourself as:

$ gem install active_filters

Let's say you have several scopes on your User model

class User < ApplicationRecord
    scope :country, -> country_code { where(country: country_code) }
    scope :gender, -> gender { where(gender: gender) }
end

And you want to chain thoses two scopes. You first need to include the Filterable controller module in your application controller

class ApplicationController < ActionController::Base
    include ActiveFilters::Controller::Filterable
end

and then include the model Filterable one in the model you want to filter.

class User < ApplicationRecord
    include ActiveFilters::Model::Filterable

    scope :country, -> country_code { where(country: country_code) }
    scope :gender, -> gender { where(gender: gender) }
end

Then you just need to declare your named scopes as filters using the has_filters DSL

class UsersController < ApplicationController
    has_filters :country, :gender
end

and apply them to a specific resource using the filter class method and the filterable params hash of params as argument.

class UsersController < ApplicationController
    has_filters :country, :gender

    def index
        @users = User.with_filter(filterable_params)
    end
end

For each request:

/users
#=> acts like a normal request

/users?country=FR&gender=female
#=> calls the named scope and bring only females in France

Now let's say you want to use incoming params stored as the value of a hash as scopes:

/users?filter[country]=FR&filter[gender]=female
#=> { filter: { country: 'FR', gender: 'female' } }

Then you can add the in_key attribute with the name of the key in which params are stored.

class UsersController < ApplicationController
    has_filters :country, :gender, in_key: :filter

    def index
        @users = User.filter(filterable_params)
    end
end

By default the params variable used by Active Filters is params. If you want to use another params variable, you have to create an initializer in config/initializers/active_filters.rb and set the variable name: (for instance with @params)

ActiveFilters::Setup.params_variable = '@params'

Bug reports and pull requests are welcome on GitHub at https://github.com/FidMe/active_filters.

The gem is available as open source under the terms of the MIT License.