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.start_with?("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.messages # => {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.
- MODULE ActiveModel::Validations::Callbacks
- MODULE ActiveModel::Validations::ClassMethods
- MODULE ActiveModel::Validations::HelperMethods
- CLASS ActiveModel::Validations::AcceptanceValidator
Attributes
[RW] | validation_context |
Instance Public methods
errors() Link
Returns the Errors
object that holds all information about attribute error messages.
class Person
include ActiveModel::Validations
attr_accessor :name
validates_presence_of :name
end
person = Person.new
person.valid? # => false
person.errors # => #<ActiveModel::Errors:0x007fe603816640 @messages={name:["can't be blank"]}>
invalid?(context = nil) Link
Performs the opposite of valid?
. Returns true
if errors were added, false
otherwise.
class Person
include ActiveModel::Validations
attr_accessor :name
validates_presence_of :name
end
person = Person.new
person.name = ''
person.invalid? # => true
person.name = 'david'
person.invalid? # => false
Context can optionally be supplied to define which callbacks to test against (the context is defined on the validations using :on
).
class Person
include ActiveModel::Validations
attr_accessor :name
validates_presence_of :name, on: :new
end
person = Person.new
person.invalid? # => false
person.invalid?(:new) # => true
valid?(context = nil) Link
Runs all the specified validations and returns true
if no errors were added otherwise false
.
class Person
include ActiveModel::Validations
attr_accessor :name
validates_presence_of :name
end
person = Person.new
person.name = ''
person.valid? # => false
person.name = 'david'
person.valid? # => true
Context can optionally be supplied to define which callbacks to test against (the context is defined on the validations using :on
).
class Person
include ActiveModel::Validations
attr_accessor :name
validates_presence_of :name, on: :new
end
person = Person.new
person.valid? # => true
person.valid?(:new) # => false
validate!(context = nil) Link
Runs all the validations within the specified context. Returns true
if no errors are found, raises ValidationError
otherwise.
Validations
with no :on
option will run no matter the context. Validations
with some :on
option will only run in the specified context.
validates_with(*args, &block) Link
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
validate :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
validate :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.