| Module | ActiveRecord::Validations::ClassMethods |
| In: |
vendor/rails/activerecord/lib/active_record/validations.rb
|
All of the following validations are defined in the class scope of the model that you‘re interested in validating. They offer a more declarative way of specifying when the model is valid and when it is not. It is recommended to use these over the low-level calls to validate and validate_on_create when possible.
| DEFAULT_VALIDATION_OPTIONS | = | { :on => :save, :allow_nil => false, :allow_blank => false, :message => nil |
| 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 |
# File vendor/rails/activerecord/lib/active_record/validations.rb, line 342
342: def condition_block?(condition)
343: condition.respond_to?("call") && (condition.arity == 1 || condition.arity == -1)
344: end
Creates an object just like Base.create but calls save! instead of save so an exception is raised if the record is invalid.
# File vendor/rails/activerecord/lib/active_record/validations.rb, line 904
904: def create!(attributes = nil)
905: if attributes.is_a?(Array)
906: attributes.collect { |attr| create!(attr) }
907: else
908: object = new(attributes)
909: object.save!
910: object
911: end
912: end
Determine from the given condition (whether a block, procedure, method or string) whether or not to validate the record. See validates_each.
# File vendor/rails/activerecord/lib/active_record/validations.rb, line 348
348: def evaluate_condition(condition, record)
349: case condition
350: when Symbol; record.send(condition)
351: when String; eval(condition, record.send(:binding))
352: else
353: if condition_block?(condition)
354: condition.call(record)
355: else
356: raise(
357: ActiveRecordError,
358: "Validations need to be either a symbol, string (to be eval'ed), proc/method, or " +
359: "class implementing a static validation method"
360: )
361: end
362: end
363: end
Adds a validation method or block to the class. This is useful when overriding the validate instance method becomes too unwieldly and you‘re looking for more descriptive declaration of your validations.
This can be done with a symbol pointing to a method:
class Comment < ActiveRecord::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 < ActiveRecord::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.
# File vendor/rails/activerecord/lib/active_record/validations.rb, line 327
327: def validate(*methods, &block)
328: methods << block if block_given?
329: write_inheritable_set(:validate, methods)
330: end
# File vendor/rails/activerecord/lib/active_record/validations.rb, line 332
332: def validate_on_create(*methods, &block)
333: methods << block if block_given?
334: write_inheritable_set(:validate_on_create, methods)
335: end
# File vendor/rails/activerecord/lib/active_record/validations.rb, line 337
337: def validate_on_update(*methods, &block)
338: methods << block if block_given?
339: write_inheritable_set(:validate_on_update, methods)
340: end
Encapsulates the pattern of wanting to validate the acceptance of a terms of service check box (or similar agreement). Example:
class Person < ActiveRecord::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:
# File vendor/rails/activerecord/lib/active_record/validations.rb, line 462
462: def validates_acceptance_of(*attr_names)
463: configuration = { :message => ActiveRecord::Errors.default_error_messages[:accepted], :on => :save, :allow_nil => true, :accept => "1" }
464: configuration.update(attr_names.extract_options!)
465:
466: db_cols = begin
467: column_names
468: rescue ActiveRecord::StatementInvalid
469: []
470: end
471: names = attr_names.reject { |name| db_cols.include?(name.to_s) }
472: attr_accessor(*names)
473:
474: validates_each(attr_names,configuration) do |record, attr_name, value|
475: record.errors.add(attr_name, configuration[:message]) unless value == configuration[:accept]
476: end
477: end
Validates whether the associated object or objects are all valid themselves. Works with any kind of association.
class Book < ActiveRecord::Base
has_many :pages
belongs_to :library
validates_associated :pages, :library
end
Warning: If, after the above definition, you then wrote:
class Page < ActiveRecord::Base
belongs_to :book
validates_associated :book
end
…this would specify a circular dependency and cause infinite recursion.
NOTE: This validation will not fail if the association hasn‘t been assigned. If you want to ensure that the association is both present and guaranteed to be valid, you also need to use validates_presence_of.
Configuration options:
# File vendor/rails/activerecord/lib/active_record/validations.rb, line 824
824: def validates_associated(*attr_names)
825: configuration = { :message => ActiveRecord::Errors.default_error_messages[:invalid], :on => :save }
826: configuration.update(attr_names.extract_options!)
827:
828: validates_each(attr_names, configuration) do |record, attr_name, value|
829: record.errors.add(attr_name, configuration[:message]) unless
830: (value.is_a?(Array) ? value : [value]).inject(true) { |v, r| (r.nil? || r.valid?) && v }
831: end
832: end
Encapsulates the pattern of wanting to validate a password or email address field with a confirmation. Example:
Model:
class Person < ActiveRecord::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 acccessors 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:
# File vendor/rails/activerecord/lib/active_record/validations.rb, line 428
428: def validates_confirmation_of(*attr_names)
429: configuration = { :message => ActiveRecord::Errors.default_error_messages[:confirmation], :on => :save }
430: configuration.update(attr_names.extract_options!)
431:
432: attr_accessor(*(attr_names.map { |n| "#{n}_confirmation" }))
433:
434: validates_each(attr_names, configuration) do |record, attr_name, value|
435: record.errors.add(attr_name, configuration[:message]) unless record.send("#{attr_name}_confirmation").nil? or value == record.send("#{attr_name}_confirmation")
436: end
437: end
Validates each attribute against a block.
class Person < ActiveRecord::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:
# File vendor/rails/activerecord/lib/active_record/validations.rb, line 383
383: def validates_each(*attrs)
384: options = attrs.extract_options!.symbolize_keys
385: attrs = attrs.flatten
386:
387: # Declare the validation.
388: send(validation_method(options[:on] || :save)) do |record|
389: # Don't validate when there is an :if condition and that condition is false or there is an :unless condition and that condition is true
390: unless (options[:if] && !evaluate_condition(options[:if], record)) || (options[:unless] && evaluate_condition(options[:unless], record))
391: attrs.each do |attr|
392: value = record.send(attr)
393: next if (value.nil? && options[:allow_nil]) || (value.blank? && options[:allow_blank])
394: yield record, attr, value
395: end
396: end
397: end
398: end
Validates that the value of the specified attribute is not in a particular enumerable object.
class Person < ActiveRecord::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"
validates_exclusion_of :format, :in => %w( mov avi ), :message => "extension %s is not allowed"
end
Configuration options:
# File vendor/rails/activerecord/lib/active_record/validations.rb, line 780
780: def validates_exclusion_of(*attr_names)
781: configuration = { :message => ActiveRecord::Errors.default_error_messages[:exclusion], :on => :save }
782: configuration.update(attr_names.extract_options!)
783:
784: enum = configuration[:in] || configuration[:within]
785:
786: 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?")
787:
788: validates_each(attr_names, configuration) do |record, attr_name, value|
789: record.errors.add(attr_name, configuration[:message] % value) if enum.include?(value)
790: end
791: end
Validates whether the value of the specified attribute is of the correct form by matching it against the regular expression provided.
class Person < ActiveRecord::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:
# File vendor/rails/activerecord/lib/active_record/validations.rb, line 718
718: def validates_format_of(*attr_names)
719: configuration = { :message => ActiveRecord::Errors.default_error_messages[:invalid], :on => :save, :with => nil }
720: configuration.update(attr_names.extract_options!)
721:
722: raise(ArgumentError, "A regular expression must be supplied as the :with option of the configuration hash") unless configuration[:with].is_a?(Regexp)
723:
724: validates_each(attr_names, configuration) do |record, attr_name, value|
725: record.errors.add(attr_name, configuration[:message]) unless value.to_s =~ configuration[:with]
726: end
727: end
Validates whether the value of the specified attribute is available in a particular enumerable object.
class Person < ActiveRecord::Base
validates_inclusion_of :gender, :in => %w( m f ), :message => "woah! what are you then!??!!"
validates_inclusion_of :age, :in => 0..99
validates_inclusion_of :format, :in => %w( jpg gif png ), :message => "extension %s is not included in the list"
end
Configuration options:
# File vendor/rails/activerecord/lib/active_record/validations.rb, line 748
748: def validates_inclusion_of(*attr_names)
749: configuration = { :message => ActiveRecord::Errors.default_error_messages[:inclusion], :on => :save }
750: configuration.update(attr_names.extract_options!)
751:
752: enum = configuration[:in] || configuration[:within]
753:
754: 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?")
755:
756: validates_each(attr_names, configuration) do |record, attr_name, value|
757: record.errors.add(attr_name, configuration[:message] % value) unless enum.include?(value)
758: end
759: end
Validates that the specified attribute matches the length restrictions supplied. Only one option can be used at a time:
class Person < ActiveRecord::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 :phone, :in => 7..32, :allow_blank => 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:
# File vendor/rails/activerecord/lib/active_record/validations.rb, line 557
557: def validates_length_of(*attrs)
558: # Merge given options with defaults.
559: options = {
560: :too_long => ActiveRecord::Errors.default_error_messages[:too_long],
561: :too_short => ActiveRecord::Errors.default_error_messages[:too_short],
562: :wrong_length => ActiveRecord::Errors.default_error_messages[:wrong_length]
563: }.merge(DEFAULT_VALIDATION_OPTIONS)
564: options.update(attrs.extract_options!.symbolize_keys)
565:
566: # Ensure that one and only one range option is specified.
567: range_options = ALL_RANGE_OPTIONS & options.keys
568: case range_options.size
569: when 0
570: raise ArgumentError, 'Range unspecified. Specify the :within, :maximum, :minimum, or :is option.'
571: when 1
572: # Valid number of options; do nothing.
573: else
574: raise ArgumentError, 'Too many range options specified. Choose only one.'
575: end
576:
577: # Get range option and value.
578: option = range_options.first
579: option_value = options[range_options.first]
580:
581: case option
582: when :within, :in
583: raise ArgumentError, ":#{option} must be a Range" unless option_value.is_a?(Range)
584:
585: too_short = options[:too_short] % option_value.begin
586: too_long = options[:too_long] % option_value.end
587:
588: validates_each(attrs, options) do |record, attr, value|
589: if value.nil? or value.split(//).size < option_value.begin
590: record.errors.add(attr, too_short)
591: elsif value.split(//).size > option_value.end
592: record.errors.add(attr, too_long)
593: end
594: end
595: when :is, :minimum, :maximum
596: raise ArgumentError, ":#{option} must be a nonnegative Integer" unless option_value.is_a?(Integer) and option_value >= 0
597:
598: # Declare different validations per option.
599: validity_checks = { :is => "==", :minimum => ">=", :maximum => "<=" }
600: message_options = { :is => :wrong_length, :minimum => :too_short, :maximum => :too_long }
601:
602: message = (options[:message] || options[message_options[option]]) % option_value
603:
604: validates_each(attrs, options) do |record, attr, value|
605: if value.kind_of?(String)
606: record.errors.add(attr, message) unless !value.nil? and value.split(//).size.method(validity_checks[option])[option_value]
607: else
608: record.errors.add(attr, message) unless !value.nil? and value.size.method(validity_checks[option])[option_value]
609: end
610: end
611: end
612: end
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 < ActiveRecord::Base
validates_numericality_of :value, :on => :create
end
Configuration options:
# File vendor/rails/activerecord/lib/active_record/validations.rb, line 860
860: def validates_numericality_of(*attr_names)
861: configuration = { :on => :save, :only_integer => false, :allow_nil => false }
862: configuration.update(attr_names.extract_options!)
863:
864:
865: numericality_options = ALL_NUMERICALITY_CHECKS.keys & configuration.keys
866:
867: (numericality_options - [ :odd, :even ]).each do |option|
868: raise ArgumentError, ":#{option} must be a number" unless configuration[option].is_a?(Numeric)
869: end
870:
871: validates_each(attr_names,configuration) do |record, attr_name, value|
872: raw_value = record.send("#{attr_name}_before_type_cast") || value
873:
874: next if configuration[:allow_nil] and raw_value.nil?
875:
876: if configuration[:only_integer]
877: unless raw_value.to_s =~ /\A[+-]?\d+\Z/
878: record.errors.add(attr_name, configuration[:message] || ActiveRecord::Errors.default_error_messages[:not_a_number])
879: next
880: end
881: raw_value = raw_value.to_i
882: else
883: begin
884: raw_value = Kernel.Float(raw_value.to_s)
885: rescue ArgumentError, TypeError
886: record.errors.add(attr_name, configuration[:message] || ActiveRecord::Errors.default_error_messages[:not_a_number])
887: next
888: end
889: end
890:
891: numericality_options.each do |option|
892: case option
893: when :odd, :even
894: record.errors.add(attr_name, configuration[:message] || ActiveRecord::Errors.default_error_messages[option]) unless raw_value.to_i.method(ALL_NUMERICALITY_CHECKS[option])[]
895: else
896: record.errors.add(attr_name, configuration[:message] || (ActiveRecord::Errors.default_error_messages[option] % configuration[option])) unless raw_value.method(ALL_NUMERICALITY_CHECKS[option])[configuration[option]]
897: end
898: end
899: end
900: end
Validates that the specified attributes are not blank (as defined by Object#blank?). Happens by default on save. Example:
class Person < ActiveRecord::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:
Validate the presence of the foreign key, not the instance variable itself. Do this:
validates_presence_of :invoice_id
Not this:
validates_presence_of :invoice
If you validate the presence of the associated object, you will get failures on saves when both the parent object and the child object are new.
# File vendor/rails/activerecord/lib/active_record/validations.rb, line 512
512: def validates_presence_of(*attr_names)
513: configuration = { :message => ActiveRecord::Errors.default_error_messages[:blank], :on => :save }
514: configuration.update(attr_names.extract_options!)
515:
516: # can't use validates_each here, because it cannot cope with nonexistent attributes,
517: # while errors.add_on_empty can
518: send(validation_method(configuration[:on])) do |record|
519: unless (configuration[:if] && !evaluate_condition(configuration[:if], record)) || (configuration[:unless] && evaluate_condition(configuration[:unless], record))
520: record.errors.add_on_blank(attr_names, configuration[:message])
521: end
522: end
523: end
Validates whether the value of the specified attributes are unique across the system. Useful for making sure that only one user can be named "davidhh".
class Person < ActiveRecord::Base
validates_uniqueness_of :user_name, :scope => :account_id
end
It can also validate whether the value of the specified attributes are unique based on multiple scope parameters. For example, making sure that a teacher can only be on the schedule once per semester for a particular class.
class TeacherSchedule < ActiveRecord::Base
validates_uniqueness_of :teacher_id, :scope => [:semester_id, :class_id]
end
When the record is created, a check is performed to make sure that no record exists in the database with the given value for the specified attribute (that maps to a column). When the record is updated, the same check is made but disregarding the record itself.
Because this check is performed outside the database there is still a chance that duplicate values will be inserted in two parallel transactions. To guarantee against this you should create a unique index on the field. See create_index for more information.
Configuration options:
# File vendor/rails/activerecord/lib/active_record/validations.rb, line 650
650: def validates_uniqueness_of(*attr_names)
651: configuration = { :message => ActiveRecord::Errors.default_error_messages[:taken], :case_sensitive => true }
652: configuration.update(attr_names.extract_options!)
653:
654: validates_each(attr_names,configuration) do |record, attr_name, value|
655: if value.nil? || (configuration[:case_sensitive] || !columns_hash[attr_name.to_s].text?)
656: condition_sql = "#{record.class.table_name}.#{attr_name} #{attribute_condition(value)}"
657: condition_params = [value]
658: else
659: condition_sql = "LOWER(#{record.class.table_name}.#{attr_name}) #{attribute_condition(value)}"
660: condition_params = [value.downcase]
661: end
662:
663: if scope = configuration[:scope]
664: Array(scope).map do |scope_item|
665: scope_value = record.send(scope_item)
666: condition_sql << " AND #{record.class.table_name}.#{scope_item} #{attribute_condition(scope_value)}"
667: condition_params << scope_value
668: end
669: end
670:
671: unless record.new_record?
672: condition_sql << " AND #{record.class.table_name}.#{record.class.primary_key} <> ?"
673: condition_params << record.send(:id)
674: end
675:
676: # The check for an existing value should be run from a class that
677: # isn't abstract. This means working down from the current class
678: # (self), to the first non-abstract class. Since classes don't know
679: # their subclasses, we have to build the hierarchy between self and
680: # the record's class.
681: class_hierarchy = [record.class]
682: while class_hierarchy.first != self
683: class_hierarchy.insert(0, class_hierarchy.first.superclass)
684: end
685:
686: # Now we can work our way down the tree to the first non-abstract
687: # class (which has a database table to query from).
688: finder_class = class_hierarchy.detect { |klass| !klass.abstract_class? }
689:
690: if finder_class.find(:first, :conditions => [condition_sql, *condition_params])
691: record.errors.add(attr_name, configuration[:message])
692: end
693: end
694: end