module ActiveModel::Validations
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.
Active Model Acceptance Validator¶ ↑
Active Model Confirmation Validator¶ ↑
Active Model Exclusion Validator¶ ↑
Active Model Format Validator¶ ↑
Active Model Inclusion Validator¶ ↑
Active Model Length Validator¶ ↑
Active Model Numericality Validator¶ ↑
Active Model Presence Validator¶ ↑
Active Model validates method¶ ↑
Public Instance Methods
Returns the Errors
object that holds all information about
attribute error messages.
# File lib/active_model/validations.rb, line 185 def errors @errors ||= Errors.new(self) end
Performs the opposite of valid?
. Returns true if errors were
added, false otherwise.
# File lib/active_model/validations.rb, line 202 def invalid?(context = nil) !valid?(context) end
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).
# File lib/active_model/validations.rb, line 192 def valid?(context = nil) current_context, self.validation_context = validation_context, context errors.clear run_validations! ensure self.validation_context = current_context end
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.
# File lib/active_model/validations/with.rb, line 134 def validates_with(*args, &block) options = args.extract_options! args.each do |klass| validator = klass.new(options, &block) validator.validate(self) end end
Protected Instance Methods
# File lib/active_model/validations.rb, line 227 def run_validations! run_callbacks :validate errors.empty? end