HasSiblings

My brother from another mother!

Add this line to your application's Gemfile:

gem 'has_siblings'

And then execute:

$ bundle

Or install it yourself as:

$ gem install has_siblings

Add has_siblings to a child model to get a siblings method that returns all of the parents' other children.

class Mother < ActiveRecord::Base
  has_many :children
end

class Father < ActiveRecord::Base
  has_many :children
end

class Child < ActiveRecord::Base
  belongs_to :mother, inverse_of: :children
  belongs_to :father, inverse_of: :children

  has_siblings through: [:mother, :father]
  has_siblings through: :mother, name: :step_siblings
end

An example of what it returns:

[1] pry> child
=> #<Child:0x007fe5b3371c20 id: 6, mother_id: 3, father_id: 2>
[2] pry> sister
=> #<Child:0x007fe5b3379e70 id: 7, mother_id: 3, father_id: 2>
[3] pry> brother
=> #<Child:0x007fe5b337e0b0 id: 8, mother_id: 3, father_id: 2>
[4] pry> half_sister
=> #<Child:0x007fe5b3386300 id: 9, mother_id: 3, father_id: nil>
[5] pry> just_a_friend
=> #<Child:0x007fe5b338c390 id: 10, mother_id: 4, father_id: nil>
[6] pry> child.siblings
=> [#<Child:0x007fe5b33dc6b0 id: 7, mother_id: 3, father_id: 2>,
    #<Child:0x007fe5b33dc3e0 id: 8, mother_id: 3, father_id: 2>]
[7] pry> child.step_siblings
=> [#<Child:0x007fe5b335fcc8 id: 7, mother_id: 3, father_id: 2>,
    #<Child:0x007fe5b335f9d0 id: 8, mother_id: 3, father_id: 2>,
    #<Child:0x007fe5b335f598 id: 9, mother_id: 3, father_id: nil>]

has_siblings accepts a through: [...] option that specifies the parents and can be an array or a single symbol, and an optional name that will be the name of the siblings method (default to siblings). By default, when specifying an array of parents, any nil association will result in an empty sibling collection, if parents can optionally be blank setting allow_nil: true will include the present parents and and the missing parent as conditions to the sibling scope.

ActiveRecord.version.to_s >= "4.0"

After checking out the repo, run bin/setup to install dependencies. Then, run rake rspec 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. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

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