ActiveRecord Helper Methods

A quick and easy way to add certain types of helper methods to your ActiveRecord models.

Currently supported

Finder methods
Accessor methods

Installation

Add this line to your application's Gemfile:

gem 'activerecord_helper_methods'

And then execute:

$ bundle install

Or install it yourself as:

$ gem install activerecord_helper_methods

Usage

add_accessor_methods

This helper takes a column name and an array of values.

class Ticket < ActiveRecord::Base
  STATUSES = %w[not_started in_progress completed]

  add_accessor_methods column: :status, values: STATUSES
end

Result: it defines an instance method for each value:

ticket = Ticket.create!(status: "in_progress")

ticket.not_started?
=> false
ticket.in_progress?
=> true
ticket.completed?
=> false

Without the helper, this is more verbose, and requires more maintenance because it would require a new instance method to be added manually whenever a new status is added:

class Ticket < ActiveRecord::Base
  STATUSES = %w[not_started in_progress completed]

  def not_started?
    status == "not_started"
  end

  def in_progress?
    status == "in_progress"
  end

  def completed?
    status == "completed"
  end
end

This can also be done using meta-programming, as this gem does, but this may add unwanted complexity to your project.

add_finder_methods

This helper takes a column name and an array of values.

class Ticket < ActiveRecord::Base
  STATUSES = %w[not_started in_progress completed]

  add_finder_methods column: :status, values: STATUSES
end

Result: it defines a class method for each value, that filters by that value:

ticket_not_started = Ticket.create!(status: "not_started")
ticket_in_progress = Ticket.create!(status: "in_progress")
ticket_completed = Ticket.create!(status: "completed")

Ticket.count
=> 3
Ticket.not_started
# Returns an ActiveRecord::Relation object that contains only ticket_not_started
Ticket.in_progress
# Returns an ActiveRecord::Relation object that contains only ticket_in_progress
Ticket.completed
# Returns an ActiveRecord::Relation object that contains only ticket_completed

Each method returns an ActiveRecord::Relation, and so are chainable with any other class methods, e.g.:

# Note: open and active are fictional class methods in this example
Ticket.open.not_started.active.count
=> 1

Without the helper, this is more verbose, and requires more maintenance because it would require a new class method (scope) to be added manually whenever a new status is added:

class Ticket < ActiveRecord::Base
  STATUSES = %w[not_started in_progress completed]

  scope :not_started, -> { where(status: "not_started") }
  scope :in_progress, -> { where(status: "in_progress") }
  scope :completed, -> { where(status: "completed") }
end

add_helper_methods

This helper adds both the accessor and finder methods.

It takes a column name and an array of values.

class Ticket < ActiveRecord::Base
  STATUSES = %w[not_started in_progress completed blocked archived approved rejected]

  add_helper_methods column: :status, values: STATUSES
end

Without the helper, this is significantly more verbose, especially when there are lots of values:

class Ticket < ActiveRecord::Base
  STATUSES = %w[not_started in_progress completed blocked archived approved rejected]

  scope :not_started, -> { where(status: "not_started") }
  scope :in_progress, -> { where(status: "in_progress") }
  scope :completed, -> { where(status: "completed") }
  scope :blocked, -> { where(status: "blocked") }
  scope :archived, -> { where(status: "archived") }
  scope :approved, -> { where(status: "approved") }
  scope :rejected, -> { where(status: "rejected") }

  def not_started?
    status == "not_started"
  end

  def in_progress?
    status == "in_progress"
  end

  def completed?
    status == "completed"
  end

  def blocked?
    status == "blocked"
  end

  def archived?
    status == "archived"
  end

  def approved?
    status == "approved"
  end

  def rejected?
    status == "rejected"
  end
end

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/harry-graham/activerecord_helper_methods. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the code of conduct.

License

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

Code of Conduct

Everyone interacting in this project's codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.