Structural
Structural is a cut down fork of Id, designed to work with Ruby >= 1.8.7 and
Rails >= 2.3.
Defining a model
class MyModel
include Structural::Model
field :foo
field :bar, default: 42
field :baz, key: 'barry'
end
my_model = MyModel.new(foo: 7, barry: 'hello')
my_model.foo # => 7
my_model.bar # => 42
my_model.baz # => 'hello'
Default values can be specified, as well as key aliases.
Associations
We can also specify has_one or has_many associations for nested documents:
class Zoo
include Structural::Model
has_many :lions
has_many :zebras
has_one :zookeeper, type: Person
end
zoo = Zoo.new(lions: [{name: 'Hetty'}],
zebras: [{name: 'Lisa'}],
zookeeper: {name: 'Russell'})
zoo.lions.first.class # => Lion
zoo.lions.first.name # => "Hetty"
zoo.zookeeper.class # => Person
zoo.zookeeper.name # => "Russell"
Types are inferred from the association name unless one is specified.
Designed for immutability
structural models provide accessor methods, but no mutator methods.
When changing the value of a field, a new copy of the object is created:
person = Person.new(name: 'Russell', job: 'programmer')
person.set(name: 'Radek')
# => returns a new Person whose name is Radek and whose job is 'programmer'
person.hat.set(colour: 'red')
# => returns a new person object with a new hat object with its colour set to red