Disposable Default
Last updated 05 May 2017 disposable v0.4Twin: Default
Twins allow default values to be set on the twin. This is provided by the Default module.
Default values can be set via :default.
class AlbumTwin < Disposable::Twin
feature Default
property :title, default: "The Greatest Songs Ever Written"
property :composer, default: Composer.new do
property :name
end
end
The default value is applied when the model’s getter returns nil in Setup.
Note that this also works for nested properties.
Struct Defaults
Defaults also work for Struct.
class AlbumTwin < Disposable::Twin
feature Default
property :settings, default: Hash.new do
include Struct
property :enabled, default: "yes"
property :roles, default: Hash.new do
include Struct
property :admin, default: "maybe"
end
end
end
You can now access nested hashes even if they were not present initially.
album = Album.new
album.settings #=> nil
twin = AlbumTwin.new(album)
twin.settings.enabled #=> "yes"
twin.settings.roles.admin #=> "maybe"
Naturally, this will then write a valid hash back in sync.
twin.sync
album.settings #=> {"enabled"=>"yes", "roles"=>{"admin"=>"maybe"}}