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