ActiveRecord::NestedAttributes::DestroyIf

Adds a :destroy_if option to .accepts_nested_attributes_for, which is basically a stronger version of :reject_if that also destroys existing records.

Use the destroy_if option when reject_if isn't strong enough, i.e. you want to also destroy existing records that pass the test, not just reject new records.

class Parent < ActiveRecord::Base
  has_many :children
  accepts_nested_attributes_for :children, destroy_if: proc { |attrs| attrs["name"].blank? }
end

class Child < ActiveRecord::Base
  belongs_to :parent
end

tywin = Parent.create!(id: 1, name: "Tywin")
Child.create!(id: 1, parent_id: 1, name: "Jaime")
Child.create!(id: 2, parent_id: 1, name: "Tyrion")

tywin.children # => [<Child id: 1, parent_id: 1, name: "Jaime">, <Child id: 2, parent_id: 1, name: "Tyrion">]

tywin.update!({
  children_attributes: {
    "0" => {
      id: 1,
      name: "Ser Jaime",
    },
    "1" => {
      id: 2,
      name: "",
    },
  },
})

tywin.children # => [<Child id: 1, parent_id: 1, name: "Ser Jaime">]

Child.find(2) # => raises ActiveRecord::RecordNotFound! Tyrion was destroyed!

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. 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/botandrose/active_record-nested_attributes-destroy_if.

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