Module: ActiveObject::Validations::ClassMethods

Defined in:
lib/active_object/validations.rb

Overview

Ant Mapper classes can implement validations in several ways. The highest level, easiest to read, and recommended approach is to use the declarative validates_..._of class methods (and validates_associated) documented below. These are sufficient for most model validations.

Slightly lower level is validates_each. It provides some of the same options as the purely declarative validation methods, but like all the lower-level approaches it requires manually adding to the errors collection when the record is invalid.

At a yet lower level, a model can use the class methods validate, validate_on_create and validate_on_update to add validation methods or blocks. These are AntSupport::Callbacks and follow the same rules of inheritance and chaining.

The lowest level style is to define the instance methods validate, validate_on_create and validate_on_update as documented in AntObject::Validations.

validate, validate_on_create and validate_on_update Class Methods

Calls to these methods add a validation method or block to the class. Again, this approach is recommended only when the higher-level methods documented below (validates_..._of and validates_associated) are insufficient to handle the required validation.

This can be done with a symbol pointing to a method:

class Comment < ActiveObject::Base
  validate :must_be_friends

  def must_be_friends
    errors.add_to_base("Must be friends to leave a comment") unless commenter.friend_of?(commentee)
  end
end

Or with a block which is passed the current record to be validated:

class Comment < ActiveObject::Base
  validate do |comment|
    comment.must_be_friends
  end

  def must_be_friends
    errors.add_to_base("Must be friends to leave a comment") unless commenter.friend_of?(commentee)
  end
end

This usage applies to validate_on_create and validate_on_update as well.

Constant Summary collapse

DEFAULT_VALIDATION_OPTIONS = 
{
  :on => :save,
  :allow_nil => false,
  :allow_blank => false,
  :message => nil
}.freeze
ALL_RANGE_OPTIONS = 
[ :is, :within, :in, :minimum, :maximum ].freeze
ALL_NUMERICALITY_CHECKS = 
{ :greater_than => '>', :greater_than_or_equal_to => '>=',
:equal_to => '==', :less_than => '<', :less_than_or_equal_to => '<=',
:odd => 'odd?', :even => 'even?' }.freeze

Instance Method Summary collapse

Instance Method Details

#create!(attributes = nil, &block) ⇒ Object

Creates an object just like Base.create but calls save! instead of save so an exception is raised if the record is invalid.



610
611
612
613
614
615
616
617
618
619
 
# File 'lib/active_object/validations.rb', line 610

def create!(attributes = nil, &block)
  if attributes.is_a?(Array)
    attributes.collect { |attr| create!(attr, &block) }
  else
    object = new(attributes)
    yield(object) if block_given?
    object.save!
    object
  end
end

#validates_acceptance_of(*attr_names) ⇒ Object

Encapsulates the pattern of wanting to validate the acceptance of a terms of service check box (or similar agreement). Example:

class Person < ActiveObject::Base
  validates_acceptance_of :terms_of_service
  validates_acceptance_of :eula, :message => "must be abided"
end

If the database column does not exist, the terms_of_service attribute is entirely virtual. This check is performed only if terms_of_service is not nil and by default on save.

Configuration options:

  • :message - A custom error message (default is: “must be accepted”).

  • :on - Specifies when this validation is active (default is :save, other options :create, :update).

  • :allow_nil - Skip validation if attribute is nil (default is true).

  • :accept - Specifies value that is considered accepted. The default value is a string “1”, which makes it easy to relate to an HTML checkbox. This should be set to true if you are validating a database column, since the attribute is typecast from “1” to true before validation.

  • :if - Specifies a method, proc or string to call to determine if the validation should occur (e.g. :if => :allow_validation, or :if => Proc.new { |user| user.signup_step > 2 }). The method, proc or string should return or evaluate to a true or false value.

  • :unless - Specifies a method, proc or string to call to determine if the validation should not occur (e.g. :unless => :skip_validation, or :unless => Proc.new { |user| user.signup_step <= 2 }). The method, proc or string should return or evaluate to a true or false value.



353
354
355
356
357
358
359
360
361
362
363
364
365
 
# File 'lib/active_object/validations.rb', line 353

def validates_acceptance_of(*attr_names)
  configuration = { :on => :save, :allow_nil => true, :accept => "1" }
  configuration.update(attr_names.extract_options!)

  names = attr_names.reject { |name| self.class.attributes.include?(name.to_s) }
  attr_accessor(*names)

  validates_each(attr_names,configuration) do |record, attr_name, value|
    unless value == configuration[:accept]
      record.errors.add(attr_name, :default => configuration[:message])
    end
  end
end

#validates_confirmation_of(*attr_names) ⇒ Object

Encapsulates the pattern of wanting to validate a password or email address field with a confirmation. Example:

Model:
  class Person < ActiveObject::Base
    validates_confirmation_of :user_name, :password
    validates_confirmation_of :email_address, :message => "should match confirmation"
  end

View:
  <%= password_field "person", "password" %>
  <%= password_field "person", "password_confirmation" %>

The added password_confirmation attribute is virtual; it exists only as an in-memory attribute for validating the password. To achieve this, the validation adds accessors to the model for the confirmation attribute. NOTE: This check is performed only if password_confirmation is not nil, and by default only on save. To require confirmation, make sure to add a presence check for the confirmation attribute:

validates_presence_of :password_confirmation, :if => :password_changed?

Configuration options:

  • :message - A custom error message (default is: “doesn’t match confirmation”).

  • :on - Specifies when this validation is active (default is :save, other options :create, :update).

  • :if - Specifies a method, proc or string to call to determine if the validation should occur (e.g. :if => :allow_validation, or :if => Proc.new { |user| user.signup_step > 2 }). The method, proc or string should return or evaluate to a true or false value.

  • :unless - Specifies a method, proc or string to call to determine if the validation should not occur (e.g. :unless => :skip_validation, or :unless => Proc.new { |user| user.signup_step <= 2 }). The method, proc or string should return or evaluate to a true or false value.



317
318
319
320
321
322
323
324
325
326
327
328
 
# File 'lib/active_object/validations.rb', line 317

def validates_confirmation_of(*attr_names)
  configuration = { :on => :save }
  configuration.update(attr_names.extract_options!)

  attr_accessor(*(attr_names.map { |n| "#{n}_confirmation" }))

  validates_each(attr_names, configuration) do |record, attr_name, value|
    unless record.send("#{attr_name}_confirmation").nil? or value == record.send("#{attr_name}_confirmation")
      record.errors.add(attr_name, :default => configuration[:message])
    end
  end
end

#validates_each(*attrs) ⇒ Object

Validates each attribute against a block.

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

Options:

  • :on - Specifies when this validation is active (default is :save, other options :create, :update).

  • :allow_nil - Skip validation if attribute is nil.

  • :allow_blank - Skip validation if attribute is blank.

  • :if - Specifies a method, proc or string to call to determine if the validation should occur (e.g. :if => :allow_validation, or :if => Proc.new { |user| user.signup_step > 2 }). The method, proc or string should return or evaluate to a true or false value.

  • :unless - Specifies a method, proc or string to call to determine if the validation should not occur (e.g. :unless => :skip_validation, or :unless => Proc.new { |user| user.signup_step <= 2 }). The method, proc or string should return or evaluate to a true or false value.



275
276
277
278
279
280
281
282
283
284
285
286
287
 
# File 'lib/active_object/validations.rb', line 275

def validates_each(*attrs)
  options = attrs.extract_options!.symbolize_keys
  attrs   = attrs.flatten

  # Declare the validation.
  send(validation_method(options[:on] || :save), options) do |record|
    attrs.each do |attr|
      value = record.send(attr)
      next if (value.nil? && options[:allow_nil]) || (value.blank? && options[:allow_blank])
      yield record, attr, value
    end
  end
end

#validates_exclusion_of(*attr_names) ⇒ Object

Validates that the value of the specified attribute is not in a particular enumerable object.

class Person < ActiveObject::Base
  validates_exclusion_of :username, :in => %w( admin superuser ), :message => "You don't belong here"
  validates_exclusion_of :age, :in => 30..60, :message => "This site is only for under 30 and over 60"
end

Configuration options:

  • in - An enumerable object of items that the value shouldn’t be part of

  • message - Specifies a customer error message (default is: “is reserved”)

  • allow_nil - If set to true, skips this validation if the attribute is null (default is: false)

  • if - Specifies a method, proc or string to call to determine if the validation should

occur (e.g. :if => :allow_validation, or :if => Proc.new { |user| user.signup_step > 2 }). The method, proc or string should return or evaluate to a true or false value.

Raises:

  • (ArgumentError) 


557
558
559
560
561
562
563
564
565
566
567
568
 
# File 'lib/active_object/validations.rb', line 557

def validates_exclusion_of(*attr_names)
  configuration = { :message => ActiveObject::Errors.default_error_messages[:exclusion], :on => :save }
  configuration.update(attr_names.pop) if attr_names.last.is_a?(Hash)

  enum = configuration[:in] || configuration[:within]

  raise(ArgumentError, "An object with the method include? is required must be supplied as the :in option of the configuration hash") unless enum.respond_to?("include?")

  validates_each(attr_names, configuration) do |record, attr_name, value|
    record.errors.add(attr_name, configuration[:message]) if enum.include?(value)
  end
end

#validates_format_of(*attr_names) ⇒ Object

Validates whether the value of the specified attribute is of the correct form by matching it against the regular expression provided.

class Person < ActiveObject::Base
  validates_format_of :email, :with => /\A([^@\s]+)@((?:[-a-z0-9]+\.)+[a-z]{2,})\Z/i, :on => :create
end

Note: use A and Z to match the start and end of the string, ^ and $ match the start/end of a line.

A regular expression must be provided or else an exception will be raised.

Configuration options:

  • message - A custom error message (default is: “is invalid”)

  • with - The regular expression used to validate the format with (note: must be supplied!)

  • on Specifies when this validation is active (default is :save, other options :create, :update)

  • if - Specifies a method, proc or string to call to determine if the validation should

occur (e.g. :if => :allow_validation, or :if => Proc.new { |user| user.signup_step > 2 }). The method, proc or string should return or evaluate to a true or false value.

Raises:

  • (ArgumentError) 


505
506
507
508
509
510
511
512
513
514
 
# File 'lib/active_object/validations.rb', line 505

def validates_format_of(*attr_names)
  configuration = { :message => ActiveObject::Errors.default_error_messages[:invalid], :on => :save, :with => nil }
  configuration.update(attr_names.pop) if attr_names.last.is_a?(Hash)

  raise(ArgumentError, "A regular expression must be supplied as the :with option of the configuration hash") unless configuration[:with].is_a?(Regexp)

  validates_each(attr_names, configuration) do |record, attr_name, value|
    record.errors.add(attr_name, configuration[:message]) unless value.to_s =~ configuration[:with]
  end
end

#validates_inclusion_of(*attr_names) ⇒ Object

Validates whether the value of the specified attribute is available in a particular enumerable object.

class Person < ActiveObject::Base
  validates_inclusion_of :gender, :in=>%w( m f ), :message=>"woah! what are you then!??!!"
  validates_inclusion_of :age, :in=>0..99
end

Configuration options:

  • in - An enumerable object of available items

  • message - Specifies a customer error message (default is: “is not included in the list”)

  • allow_nil - If set to true, skips this validation if the attribute is null (default is: false)

  • if - Specifies a method, proc or string to call to determine if the validation should

occur (e.g. :if => :allow_validation, or :if => Proc.new { |user| user.signup_step > 2 }). The method, proc or string should return or evaluate to a true or false value.

Raises:

  • (ArgumentError) 


530
531
532
533
534
535
536
537
538
539
540
541
 
# File 'lib/active_object/validations.rb', line 530

def validates_inclusion_of(*attr_names)
  configuration = { :message => ActiveObject::Errors.default_error_messages[:inclusion], :on => :save }
  configuration.update(attr_names.pop) if attr_names.last.is_a?(Hash)

  enum = configuration[:in] || configuration[:within]

  raise(ArgumentError, "An object with the method include? is required must be supplied as the :in option of the configuration hash") unless enum.respond_to?("include?")

  validates_each(attr_names, configuration) do |record, attr_name, value|
    record.errors.add(attr_name, configuration[:message]) unless enum.include?(value)
  end
end

#validates_length_of(*attrs) ⇒ Object Also known as: validates_size_of

class Person < ActiveObject::Base

  validates_length_of :first_name, :maximum=>30
  validates_length_of :last_name, :maximum=>30, :message=>"less than %d if you don't mind"
  validates_length_of :fax, :in => 7..32, :allow_nil => true
  validates_length_of :user_name, :within => 6..20, :too_long => "pick a shorter name", :too_short => "pick a longer name"
  validates_length_of :fav_bra_size, :minimum=>1, :too_short=>"please enter at least %d character"
  validates_length_of :smurf_leader, :is=>4, :message=>"papa is spelled with %d characters... don't play me."
end

Configuration options:

  • minimum - The minimum size of the attribute

  • maximum - The maximum size of the attribute

  • is - The exact size of the attribute

  • within - A range specifying the minimum and maximum size of the attribute

  • in - A synonym(or alias) for :within

  • allow_nil - Attribute may be nil; skip validation.

  • too_long - The error message if the attribute goes over the maximum (default is: “is too long (maximum is %d characters)”)

  • too_short - The error message if the attribute goes under the minimum (default is: “is too short (min is %d characters)”)

  • wrong_length - The error message if using the :is method and the attribute is the wrong size (default is: “is the wrong length (should be %d characters)”)

  • message - The error message to use for a :minimum, :maximum, or :is violation. An alias of the appropriate too_long/too_short/wrong_length message

  • on - Specifies when this validation is active (default is :save, other options :create, :update)

  • if - Specifies a method, proc or string to call to determine if the validation should

occur (e.g. :if => :allow_validation, or :if => Proc.new { |user| user.signup_step > 2 }). The method, proc or string should return or evaluate to a true or false value.



427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
 
# File 'lib/active_object/validations.rb', line 427

def validates_length_of(*attrs)
  # Merge given options with defaults.
  options = {
    :too_long     => ActiveObject::Errors.default_error_messages[:too_long],
    :too_short    => ActiveObject::Errors.default_error_messages[:too_short],
    :wrong_length => ActiveObject::Errors.default_error_messages[:wrong_length]
  }.merge(DEFAULT_VALIDATION_OPTIONS)
  options.update(attrs.pop.symbolize_keys) if attrs.last.is_a?(Hash)

  # Ensure that one and only one range option is specified.
  range_options = ALL_RANGE_OPTIONS & options.keys
  case range_options.size
    when 0
      raise ArgumentError, 'Range unspecified.  Specify the :within, :maximum, :minimum, or :is option.'
    when 1
      # Valid number of options; do nothing.
    else
      raise ArgumentError, 'Too many range options specified.  Choose only one.'
  end

  # Get range option and value.
  option = range_options.first
  option_value = options[range_options.first]

  case option
    when :within, :in
      raise ArgumentError, ":#{option} must be a Range" unless option_value.is_a?(Range)

      too_short = options[:too_short] % option_value.begin
      too_long  = options[:too_long]  % option_value.end

      validates_each(attrs, options) do |record, attr, value|
        if value.nil? or value.split(//).size < option_value.begin
          record.errors.add(attr, too_short)
        elsif value.split(//).size > option_value.end
          record.errors.add(attr, too_long)
        end
      end
    when :is, :minimum, :maximum
      raise ArgumentError, ":#{option} must be a nonnegative Integer" unless option_value.is_a?(Integer) and option_value >= 0

      # Declare different validations per option.
      validity_checks = { :is => "==", :minimum => ">=", :maximum => "<=" }
      message_options = { :is => :wrong_length, :minimum => :too_short, :maximum => :too_long }

      message = (options[:message] || options[message_options[option]]) % option_value

      validates_each(attrs, options) do |record, attr, value|
        if value.kind_of?(String)
          record.errors.add(attr, message) unless !value.nil? and value.split(//).size.method(validity_checks[option])[option_value]
        else
          record.errors.add(attr, message) unless !value.nil? and value.size.method(validity_checks[option])[option_value]
        end
      end
  end
end

#validates_numericality_of(*attr_names) ⇒ Object

Validates whether the value of the specified attribute is numeric by trying to convert it to a float with Kernel.Float (if integer is false) or applying it to the regular expression /\A[+\-]?\d+\Z/ (if integer is set to true).

class Person < ActiveObject::Base
  validates_numericality_of :value, :on => :create
end

Configuration options:

  • message - A custom error message (default is: “is not a number”)

  • on Specifies when this validation is active (default is :save, other options :create, :update)

  • only_integer Specifies whether the value has to be an integer, e.g. an integral value (default is false)

  • allow_nil Skip validation if attribute is nil (default is false). Notice that for fixnum and float columns empty strings are converted to nil

  • if - Specifies a method, proc or string to call to determine if the validation should

occur (e.g. :if => :allow_validation, or :if => Proc.new { |user| user.signup_step > 2 }). The method, proc or string should return or evaluate to a true or false value.



587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
 
# File 'lib/active_object/validations.rb', line 587

def validates_numericality_of(*attr_names)
  configuration = { :message => ActiveObject::Errors.default_error_messages[:not_a_number], :on => :save,
                     :only_integer => false, :allow_nil => false }
  configuration.update(attr_names.pop) if attr_names.last.is_a?(Hash)

  if configuration[:only_integer]
    validates_each(attr_names,configuration) do |record, attr_name,value|
      record.errors.add(attr_name, configuration[:message]) unless record.send("#{attr_name}_before_type_cast").to_s =~ /\A[+-]?\d+\Z/
    end
  else
    validates_each(attr_names,configuration) do |record, attr_name,value|
     next if configuration[:allow_nil] and record.send("#{attr_name}_before_type_cast").nil?
      begin
        Kernel.Float(record.send("#{attr_name}_before_type_cast").to_s)
      rescue ArgumentError, TypeError
        record.errors.add(attr_name, configuration[:message])
      end
    end
  end
end

#validates_presence_of(*attr_names) ⇒ Object

Validates that the specified attributes are not blank (as defined by Object#blank?). Happens by default on save. Example:

class Person < ActiveObject::Base
  validates_presence_of :first_name
end

The first_name attribute must be in the object and it cannot be blank.

If you want to validate the presence of a boolean field (where the real values are true and false), you will want to use validates_inclusion_of :field_name, :in => [true, false] This is due to the way Object#blank? handles boolean values. false.blank? # => true

Configuration options:

  • message - A custom error message (default is: “can’t be blank”).

  • on - Specifies when this validation is active (default is :save, other options :create, :update).

  • if - Specifies a method, proc or string to call to determine if the validation should occur (e.g. :if => :allow_validation, or :if => Proc.new { |user| user.signup_step > 2 }). The method, proc or string should return or evaluate to a true or false value.

  • unless - Specifies a method, proc or string to call to determine if the validation should not occur (e.g. :unless => :skip_validation, or :unless => Proc.new { |user| user.signup_step <= 2 }). The method, proc or string should return or evaluate to a true or false value.



389
390
391
392
393
394
395
396
397
398
 
# File 'lib/active_object/validations.rb', line 389

def validates_presence_of(*attr_names)
  configuration = { :message => ActiveObject::Errors.default_error_messages[:blank], :on => :save }
  configuration.update(attr_names.extract_options!)

  # can't use validates_each here, because it cannot cope with nonexistent attributes,
  # while errors.add_on_empty can
  send(validation_method(configuration[:on]), configuration) do |record|
    record.errors.add_on_blank(attr_names, configuration[:message])
  end
end