Module ActiveModel::Validations
In: lib/active_model/validations/length.rb
lib/active_model/validations/format.rb
lib/active_model/validations/confirmation.rb
lib/active_model/validations/callbacks.rb
lib/active_model/validations/inclusion.rb
lib/active_model/validations/exclusion.rb
lib/active_model/validations/with.rb
lib/active_model/validations/numericality.rb
lib/active_model/validations/presence.rb
lib/active_model/validations/validates.rb
lib/active_model/validations/acceptance.rb
lib/active_model/validations.rb

Active Model Validations

Provides a full validation framework to your objects.

A minimal implementation could be:

  class Person
    include ActiveModel::Validations

    attr_accessor :first_name, :last_name

    validates_each :first_name, :last_name do |record, attr, value|
      record.errors.add attr, 'starts with z.' if value.to_s[0] == ?z
    end
  end

Which provides you with the full standard validation stack that you know from Active Record:

  person = Person.new
  person.valid?                   # => true
  person.invalid?                 # => false

  person.first_name = 'zoolander'
  person.valid?                   # => false
  person.invalid?                 # => true
  person.errors                   # => #<OrderedHash {:first_name=>["starts with z."]}>

Note that ActiveModel::Validations automatically adds an errors method to your instances initialized with a new ActiveModel::Errors object, so there is no need for you to do this manually.

Methods

Included Modules

ActiveSupport::Callbacks HelperMethods

Classes and Modules

Module ActiveModel::Validations::Callbacks
Module ActiveModel::Validations::ClassMethods
Module ActiveModel::Validations::HelperMethods
Class ActiveModel::Validations::AcceptanceValidator
Class ActiveModel::Validations::ConfirmationValidator
Class ActiveModel::Validations::ExclusionValidator
Class ActiveModel::Validations::FormatValidator
Class ActiveModel::Validations::InclusionValidator
Class ActiveModel::Validations::LengthValidator
Class ActiveModel::Validations::NumericalityValidator
Class ActiveModel::Validations::PresenceValidator

External Aliases

send -> read_attribute_for_validation
  Hook method defining how an attribute value should be retrieved. By default this is assumed to be an instance named after the attribute. Override this method in subclasses should you need to retrieve the value for a given attribute differently:
  class MyClass
    include ActiveModel::Validations

    def initialize(data = {})
      @data = data
    end

    def read_attribute_for_validation(key)
      @data[key]
    end
  end

Public Instance methods

Returns the Errors object that holds all information about attribute error messages.

Performs the opposite of valid?. Returns true if errors were added, false otherwise.

Runs all the specified validations and returns true if no errors were added otherwise false. Context can optionally be supplied to define which callbacks to test against (the context is defined on the validations using :on).

Passes the record off to the class or classes specified and allows them to add errors based on more complex conditions.

  class Person
    include ActiveModel::Validations

    validates :instance_validations

    def instance_validations
      validates_with MyValidator
    end
  end

Please consult the class method documentation for more information on creating your own validator.

You may also pass it multiple classes, like so:

  class Person
    include ActiveModel::Validations

    validates :instance_validations, :on => :create

    def instance_validations
      validates_with MyValidator, MyOtherValidator
    end
  end

Standard configuration options (:on, :if and :unless), which are available on the class version of validates_with, should instead be placed on the validates method as these are applied and tested in the callback

If you pass any additional configuration options, they will be passed to the class and available as options, please refer to the class version of this method for more information

Protected Instance methods

[Validate]