module ActiveModel::Model - activemodel-4.2.3 Documentation

# module ActiveModel::Model

## Active Model Basic Model¶ ↑

Includes the required interface for an object to interact with `ActionPack`, using different `ActiveModel` modules. It includes model name introspections, conversions, translations and validations. Besides that, it allows you to initialize the object with a hash of attributes, pretty much like `ActiveRecord` does.

A minimal implementation could be:

    class Person
      include ActiveModel::Model
      attr_accessor :name, :age
    end

    person = Person.new(name: 'bob', age: '18')
    person.name # => "bob"
    person.age  # => "18"

Note that, by default, `ActiveModel::Model` implements `persisted?` to return `false`, which is the most common case. You may want to override it in your class to simulate a different scenario:

    class Person
      include ActiveModel::Model
      attr_accessor :id, :name

      def persisted?
        self.id == 1
      end
    end

    person = Person.new(id: 1, name: 'bob')
    person.persisted? # => true

Also, if for some reason you need to run code on `initialize`, make sure you call `super` if you want the attributes hash initialization to happen.

    class Person
      include ActiveModel::Model
      attr_accessor :id, :name, :omg

      def initialize(attributes={})
        super
        @omg ||= true
      end
    end

    person = Person.new(id: 1, name: 'bob')
    person.omg # => true

For more detailed information on other functionalities available, please refer to the specific modules included in `ActiveModel::Model` (see below).

### Public Class Methods

new(params={}) click to toggle source

Initializes a new model with the given `params`.

    class Person
      include ActiveModel::Model
      attr_accessor :name, :age
    end

    person = Person.new(name: 'bob', age: '18')
    person.name # => "bob"
    person.age  # => "18"

Calls superclass method

    # File lib/active_model/model.rb, line 78
    def initialize(params={})
      params.each do |attr, value|
        self.public_send("#{attr}=", value)
      end if params

      super()
    end

### Public Instance Methods

persisted?() click to toggle source

Indicates if the model is persisted. Default is `false`.

    class Person
      include ActiveModel::Model
      attr_accessor :id, :name
    end

    person = Person.new(id: 1, name: 'bob')
    person.persisted? # => false

    # File lib/active_model/model.rb, line 95
    def persisted?
      false
    end