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
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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"]}>
freeze() Link
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.
validation_context() Link
Returns the context when running validations.