module ActiveRecord # Raised by save! and create! when the record is invalid. Use the # +record+ method to retrieve the record which did not validate. # begin # complex_operation_that_calls_save!_internally # rescue ActiveRecord::RecordInvalid => invalid # puts invalid.record.errors # end class RecordInvalid < ActiveRecordError attr_reader :record def initialize(record) @record = record super("Validation failed: #{@record.errors.full_messages.join(", ")}") end end # Active Record validation is reported to and from this object, which is used by Base#save to # determine whether the object is in a valid state to be saved. See usage example in Validations. class Errors include Enumerable class << self def default_error_messages ActiveSupport::Deprecation.warn("ActiveRecord::Errors.default_error_messages has been deprecated. Please use I18n.translate('activerecord.errors.messages').") I18n.translate 'activerecord.errors.messages' end end def initialize(base) # :nodoc: @base, @errors = base, {} end # Adds an error to the base object instead of any particular attribute. This is used # to report errors that don't tie to any specific attribute, but rather to the object # as a whole. These error messages don't get prepended with any field name when iterating # with +each_full+, so they should be complete sentences. def add_to_base(msg) add(:base, msg) end # Adds an error message (+messsage+) to the +attribute+, which will be returned on a call to on(attribute) # for the same attribute and ensure that this error object returns false when asked if empty?. More than one # error can be added to the same +attribute+ in which case an array will be returned on a call to on(attribute). # If no +messsage+ is supplied, :invalid is assumed. # If +message+ is a Symbol, it will be translated, using the appropriate scope (see translate_error). def add(attribute, message = nil, options = {}) message ||= :invalid message = generate_message(attribute, message, options) if message.is_a?(Symbol) @errors[attribute.to_s] ||= [] @errors[attribute.to_s] << message end # Will add an error message to each of the attributes in +attributes+ that is empty. def add_on_empty(attributes, custom_message = nil) for attr in [attributes].flatten value = @base.respond_to?(attr.to_s) ? @base.send(attr.to_s) : @base[attr.to_s] is_empty = value.respond_to?(:empty?) ? value.empty? : false add(attr, :empty, :default => custom_message) unless !value.nil? && !is_empty end end # Will add an error message to each of the attributes in +attributes+ that is blank (using Object#blank?). def add_on_blank(attributes, custom_message = nil) for attr in [attributes].flatten value = @base.respond_to?(attr.to_s) ? @base.send(attr.to_s) : @base[attr.to_s] add(attr, :blank, :default => custom_message) if value.blank? end end # Translates an error message in it's default scope (activerecord.errrors.messages). # Error messages are first looked up in models.MODEL.attributes.ATTRIBUTE.MESSAGE, if it's not there, # it's looked up in models.MODEL.MESSAGE and if that is not there it returns the translation of the # default message (e.g. activerecord.errors.messages.MESSAGE). The translated model name, # translated attribute name and the value are available for interpolation. # # When using inheritence in your models, it will check all the inherited models too, but only if the model itself # hasn't been found. Say you have class Admin < User; end and you wanted the translation for the :blank # error +message+ for the title +attribute+, it looks for these translations: # #
    #
  1. activerecord.errors.models.admin.attributes.title.blank
  2. #
  3. activerecord.errors.models.admin.blank
  4. #
  5. activerecord.errors.models.user.attributes.title.blank
  6. #
  7. activerecord.errors.models.user.blank
  8. #
  9. activerecord.errors.messages.blank
  10. #
  11. any default you provided through the +options+ hash (in the activerecord.errors scope)
  12. #
def generate_message(attribute, message = :invalid, options = {}) message, options[:default] = options[:default], message if options[:default].is_a?(Symbol) defaults = @base.class.self_and_descendents_from_active_record.map do |klass| [ :"models.#{klass.name.underscore}.attributes.#{attribute}.#{message}", :"models.#{klass.name.underscore}.#{message}" ] end defaults << options.delete(:default) defaults = defaults.compact.flatten << :"messages.#{message}" key = defaults.shift value = @base.respond_to?(attribute) ? @base.send(attribute) : nil options = { :default => defaults, :model => @base.class.human_name, :attribute => @base.class.human_attribute_name(attribute.to_s), :value => value, :scope => [:activerecord, :errors] }.merge(options) I18n.translate(key, options) end # Returns true if the specified +attribute+ has errors associated with it. # # class Company < ActiveRecord::Base # validates_presence_of :name, :address, :email # validates_length_of :name, :in => 5..30 # end # # company = Company.create(:address => '123 First St.') # company.errors.invalid?(:name) # => true # company.errors.invalid?(:address) # => false def invalid?(attribute) !@errors[attribute.to_s].nil? end # Returns +nil+, if no errors are associated with the specified +attribute+. # Returns the error message, if one error is associated with the specified +attribute+. # Returns an array of error messages, if more than one error is associated with the specified +attribute+. # # class Company < ActiveRecord::Base # validates_presence_of :name, :address, :email # validates_length_of :name, :in => 5..30 # end # # company = Company.create(:address => '123 First St.') # company.errors.on(:name) # => ["is too short (minimum is 5 characters)", "can't be blank"] # company.errors.on(:email) # => "can't be blank" # company.errors.on(:address) # => nil def on(attribute) errors = @errors[attribute.to_s] return nil if errors.nil? errors.size == 1 ? errors.first : errors end alias :[] :on # Returns errors assigned to the base object through +add_to_base+ according to the normal rules of on(attribute). def on_base on(:base) end # Yields each attribute and associated message per error added. # # class Company < ActiveRecord::Base # validates_presence_of :name, :address, :email # validates_length_of :name, :in => 5..30 # end # # company = Company.create(:address => '123 First St.') # company.errors.each{|attr,msg| puts "#{attr} - #{msg}" } # # => name - is too short (minimum is 5 characters) # # name - can't be blank # # address - can't be blank def each @errors.each_key { |attr| @errors[attr].each { |msg| yield attr, msg } } end # Yields each full error message added. So Person.errors.add("first_name", "can't be empty") will be returned # through iteration as "First name can't be empty". # # class Company < ActiveRecord::Base # validates_presence_of :name, :address, :email # validates_length_of :name, :in => 5..30 # end # # company = Company.create(:address => '123 First St.') # company.errors.each_full{|msg| puts msg } # # => Name is too short (minimum is 5 characters) # # Name can't be blank # # Address can't be blank def each_full full_messages.each { |msg| yield msg } end # Returns all the full error messages in an array. # # class Company < ActiveRecord::Base # validates_presence_of :name, :address, :email # validates_length_of :name, :in => 5..30 # end # # company = Company.create(:address => '123 First St.') # company.errors.full_messages # => # ["Name is too short (minimum is 5 characters)", "Name can't be blank", "Address can't be blank"] def full_messages(options = {}) full_messages = [] @errors.each_key do |attr| @errors[attr].each do |message| next unless message if attr == "base" full_messages << message else #key = :"activerecord.att.#{@base.class.name.underscore.to_sym}.#{attr}" attr_name = @base.class.human_attribute_name(attr) full_messages << attr_name + ' ' + message end end end full_messages end # Returns true if no errors have been added. def empty? @errors.empty? end # Removes all errors that have been added. def clear @errors = {} end # Returns the total number of errors added. Two errors added to the same attribute will be counted as such. def size @errors.values.inject(0) { |error_count, attribute| error_count + attribute.size } end alias_method :count, :size alias_method :length, :size # Returns an XML representation of this error object. # # class Company < ActiveRecord::Base # validates_presence_of :name, :address, :email # validates_length_of :name, :in => 5..30 # end # # company = Company.create(:address => '123 First St.') # company.errors.to_xml # # => # # # # Name is too short (minimum is 5 characters) # # Name can't be blank # # Address can't be blank # # def to_xml(options={}) options[:root] ||= "errors" options[:indent] ||= 2 options[:builder] ||= Builder::XmlMarkup.new(:indent => options[:indent]) options[:builder].instruct! unless options.delete(:skip_instruct) options[:builder].errors do |e| full_messages.each { |msg| e.error(msg) } end end end # Please do have a look at ActiveRecord::Validations::ClassMethods for a higher level of validations. # # Active Records implement validation by overwriting Base#validate (or the variations, +validate_on_create+ and # +validate_on_update+). Each of these methods can inspect the state of the object, which usually means ensuring # that a number of attributes have a certain value (such as not empty, within a given range, matching a certain regular expression). # # Example: # # class Person < ActiveRecord::Base # protected # def validate # errors.add_on_empty %w( first_name last_name ) # errors.add("phone_number", "has invalid format") unless phone_number =~ /[0-9]*/ # end # # def validate_on_create # is only run the first time a new object is saved # unless valid_discount?(membership_discount) # errors.add("membership_discount", "has expired") # end # end # # def validate_on_update # errors.add_to_base("No changes have occurred") if unchanged_attributes? # end # end # # person = Person.new("first_name" => "David", "phone_number" => "what?") # person.save # => false (and doesn't do the save) # person.errors.empty? # => false # person.errors.count # => 2 # person.errors.on "last_name" # => "can't be empty" # person.errors.on "phone_number" # => "has invalid format" # person.errors.each_full { |msg| puts msg } # # => "Last name can't be empty\n" + # # "Phone number has invalid format" # # person.attributes = { "last_name" => "Heinemeier", "phone_number" => "555-555" } # person.save # => true (and person is now saved in the database) # # An Errors object is automatically created for every Active Record. module Validations VALIDATIONS = %w( validate validate_on_create validate_on_update ) def self.included(base) # :nodoc: base.extend ClassMethods base.class_eval do alias_method_chain :save, :validation alias_method_chain :save!, :validation end base.send :include, ActiveSupport::Callbacks base.define_callbacks *VALIDATIONS end # Active Record 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 ActiveSupport::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 ActiveRecord::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 < 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. module ClassMethods 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 # 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: # * :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. 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 # 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 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. 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, :confirmation, :default => configuration[:message]) end end 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: # * :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. def validates_acceptance_of(*attr_names) configuration = { :on => :save, :allow_nil => true, :accept => "1" } configuration.update(attr_names.extract_options!) db_cols = begin column_names rescue Exception # To ignore both statement and connection errors [] end names = attr_names.reject { |name| db_cols.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, :accepted, :default => configuration[:message]) end end 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: # * 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. # def validates_presence_of(*attr_names) configuration = { :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 # 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 {{count}} 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 {{count}} character" # validates_length_of :smurf_leader, :is => 4, :message => "papa is spelled with {{count}} characters... don't play me." # validates_length_of :essay, :minimum => 100, :too_short => "Your essay must be at least {{count}} words."), :tokenizer => lambda {|str| str.scan(/\w+/) } # 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. # * :allow_blank - Attribute may be blank; skip validation. # * :too_long - The error message if the attribute goes over the maximum (default is: "is too long (maximum is {{count}} characters)"). # * :too_short - The error message if the attribute goes under the minimum (default is: "is too short (min is {{count}} 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 {{count}} 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. # * :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. # * :tokenizer - Specifies how to split up the attribute string. (e.g. :tokenizer => lambda {|str| str.scan(/\w+/)} to # count words as in above example.) # Defaults to lambda{ |value| value.split(//) } which counts individual characters. def validates_length_of(*attrs) # Merge given options with defaults. options = { :tokenizer => lambda {|value| value.split(//)} }.merge(DEFAULT_VALIDATION_OPTIONS) options.update(attrs.extract_options!.symbolize_keys) # 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) validates_each(attrs, options) do |record, attr, value| value = options[:tokenizer].call(value) if value.kind_of?(String) if value.nil? or value.size < option_value.begin record.errors.add(attr, :too_short, :default => options[:too_short], :count => option_value.begin) elsif value.size > option_value.end record.errors.add(attr, :too_long, :default => options[:too_long], :count => option_value.end) 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 } validates_each(attrs, options) do |record, attr, value| value = options[:tokenizer].call(value) if value.kind_of?(String) unless !value.nil? and value.size.method(validity_checks[option])[option_value] key = message_options[option] custom_message = options[:message] || options[key] record.errors.add(attr, key, :default => custom_message, :count => option_value) end end end end alias_method :validates_size_of, :validates_length_of # 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. # # Configuration options: # * :message - Specifies a custom error message (default is: "has already been taken"). # * :scope - One or more columns by which to limit the scope of the uniqueness constraint. # * :case_sensitive - Looks for an exact match. Ignored by non-text columns (+true+ by default). # * :allow_nil - If set to true, skips this validation if the attribute is +nil+ (default is +false+). # * :allow_blank - If set to true, skips this validation if the attribute is blank (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. # * :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. # # === Concurrency and integrity # # Using this validation method in conjunction with ActiveRecord::Base#save # does not guarantee the absence of duplicate record insertions, because # uniqueness checks on the application level are inherently prone to race # conditions. For example, suppose that two users try to post a Comment at # the same time, and a Comment's title must be unique. At the database-level, # the actions performed by these users could be interleaved in the following manner: # # User 1 | User 2 # ------------------------------------+-------------------------------------- # # User 1 checks whether there's | # # already a comment with the title | # # 'My Post'. This is not the case. | # SELECT * FROM comments | # WHERE title = 'My Post' | # | # | # User 2 does the same thing and also # | # infers that his title is unique. # | SELECT * FROM comments # | WHERE title = 'My Post' # | # # User 1 inserts his comment. | # INSERT INTO comments | # (title, content) VALUES | # ('My Post', 'hi!') | # | # | # User 2 does the same thing. # | INSERT INTO comments # | (title, content) VALUES # | ('My Post', 'hello!') # | # | # ^^^^^^ # | # Boom! We now have a duplicate # | # title! # # This could even happen if you use transactions with the 'serializable' # isolation level. There are several ways to get around this problem: # - By locking the database table before validating, and unlocking it after # saving. However, table locking is very expensive, and thus not # recommended. # - By locking a lock file before validating, and unlocking it after saving. # This does not work if you've scaled your Rails application across # multiple web servers (because they cannot share lock files, or cannot # do that efficiently), and thus not recommended. # - Creating a unique index on the field, by using # ActiveRecord::ConnectionAdapters::SchemaStatements#add_index. In the # rare case that a race condition occurs, the database will guarantee # the field's uniqueness. # # When the database catches such a duplicate insertion, # ActiveRecord::Base#save will raise an ActiveRecord::StatementInvalid # exception. You can either choose to let this error propagate (which # will result in the default Rails exception page being shown), or you # can catch it and restart the transaction (e.g. by telling the user # that the title already exists, and asking him to re-enter the title). # This technique is also known as optimistic concurrency control: # http://en.wikipedia.org/wiki/Optimistic_concurrency_control # # Active Record currently provides no way to distinguish unique # index constraint errors from other types of database errors, so you # will have to parse the (database-specific) exception message to detect # such a case. def validates_uniqueness_of(*attr_names) configuration = { :case_sensitive => true } configuration.update(attr_names.extract_options!) validates_each(attr_names,configuration) do |record, attr_name, value| # The check for an existing value should be run from a class that # isn't abstract. This means working down from the current class # (self), to the first non-abstract class. Since classes don't know # their subclasses, we have to build the hierarchy between self and # the record's class. class_hierarchy = [record.class] while class_hierarchy.first != self class_hierarchy.insert(0, class_hierarchy.first.superclass) end # Now we can work our way down the tree to the first non-abstract # class (which has a database table to query from). finder_class = class_hierarchy.detect { |klass| !klass.abstract_class? } is_text_column = finder_class.columns_hash[attr_name.to_s].text? if value.nil? comparison_operator = "IS ?" elsif is_text_column comparison_operator = "#{connection.case_sensitive_equality_operator} ?" value = value.to_s else comparison_operator = "= ?" end sql_attribute = "#{record.class.quoted_table_name}.#{connection.quote_column_name(attr_name)}" if value.nil? || (configuration[:case_sensitive] || !is_text_column) condition_sql = "#{sql_attribute} #{comparison_operator}" condition_params = [value] else condition_sql = "LOWER(#{sql_attribute}) #{comparison_operator}" condition_params = [value.mb_chars.downcase] end if scope = configuration[:scope] Array(scope).map do |scope_item| scope_value = record.send(scope_item) condition_sql << " AND #{record.class.quoted_table_name}.#{scope_item} #{attribute_condition(scope_value)}" condition_params << scope_value end end unless record.new_record? condition_sql << " AND #{record.class.quoted_table_name}.#{record.class.primary_key} <> ?" condition_params << record.send(:id) end finder_class.with_exclusive_scope do if finder_class.exists?([condition_sql, *condition_params]) record.errors.add(attr_name, :taken, :default => configuration[:message], :value => value) end end end 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: # * :message - A custom error message (default is: "is invalid"). # * :allow_nil - If set to true, skips this validation if the attribute is +nil+ (default is +false+). # * :allow_blank - If set to true, skips this validation if the attribute is blank (default is +false+). # * :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. # * :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. def validates_format_of(*attr_names) configuration = { :on => :save, :with => nil } configuration.update(attr_names.extract_options!) 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| unless value.to_s =~ configuration[:with] record.errors.add(attr_name, :invalid, :default => configuration[:message], :value => value) end end 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 {{value}} is not included in the list" # end # # Configuration options: # * :in - An enumerable object of available items. # * :message - Specifies a custom error message (default is: "is not included in the list"). # * :allow_nil - If set to true, skips this validation if the attribute is +nil+ (default is +false+). # * :allow_blank - If set to true, skips this validation if the attribute is blank (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. # * :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. def validates_inclusion_of(*attr_names) configuration = { :on => :save } configuration.update(attr_names.extract_options!) 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| unless enum.include?(value) record.errors.add(attr_name, :inclusion, :default => configuration[:message], :value => value) end end 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 {{value}} is not allowed" # end # # Configuration options: # * :in - An enumerable object of items that the value shouldn't be part of. # * :message - Specifies a custom error message (default is: "is reserved"). # * :allow_nil - If set to true, skips this validation if the attribute is +nil+ (default is +false+). # * :allow_blank - If set to true, skips this validation if the attribute is blank (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. # * :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. def validates_exclusion_of(*attr_names) configuration = { :on => :save } configuration.update(attr_names.extract_options!) 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| if enum.include?(value) record.errors.add(attr_name, :exclusion, :default => configuration[:message], :value => value) end end 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: # * :message - A custom error message (default is: "is invalid") # * :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. def validates_associated(*attr_names) configuration = { :on => :save } configuration.update(attr_names.extract_options!) validates_each(attr_names, configuration) do |record, attr_name, value| unless (value.is_a?(Array) ? value : [value]).inject(true) { |v, r| (r.nil? || r.valid?) && v } record.errors.add(attr_name, :invalid, :default => configuration[:message], :value => value) end end end # Validates whether the value of the specified attribute is numeric by trying to convert it to # a float with Kernel.Float (if only_integer is false) or applying it to the regular expression # /\A[\+\-]?\d+\Z/ (if only_integer is set to true). # # class Person < ActiveRecord::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+. # * :greater_than - Specifies the value must be greater than the supplied value. # * :greater_than_or_equal_to - Specifies the value must be greater than or equal the supplied value. # * :equal_to - Specifies the value must be equal to the supplied value. # * :less_than - Specifies the value must be less than the supplied value. # * :less_than_or_equal_to - Specifies the value must be less than or equal the supplied value. # * :odd - Specifies the value must be an odd number. # * :even - Specifies the value must be an even number. # * :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. def validates_numericality_of(*attr_names) configuration = { :on => :save, :only_integer => false, :allow_nil => false } configuration.update(attr_names.extract_options!) numericality_options = ALL_NUMERICALITY_CHECKS.keys & configuration.keys (numericality_options - [ :odd, :even ]).each do |option| raise ArgumentError, ":#{option} must be a number" unless configuration[option].is_a?(Numeric) end validates_each(attr_names,configuration) do |record, attr_name, value| raw_value = record.send("#{attr_name}_before_type_cast") || value next if configuration[:allow_nil] and raw_value.nil? if configuration[:only_integer] unless raw_value.to_s =~ /\A[+-]?\d+\Z/ record.errors.add(attr_name, :not_a_number, :value => raw_value, :default => configuration[:message]) next end raw_value = raw_value.to_i else begin raw_value = Kernel.Float(raw_value) rescue ArgumentError, TypeError record.errors.add(attr_name, :not_a_number, :value => raw_value, :default => configuration[:message]) next end end numericality_options.each do |option| case option when :odd, :even unless raw_value.to_i.method(ALL_NUMERICALITY_CHECKS[option])[] record.errors.add(attr_name, option, :value => raw_value, :default => configuration[:message]) end else record.errors.add(attr_name, option, :default => configuration[:message], :value => raw_value, :count => configuration[option]) unless raw_value.method(ALL_NUMERICALITY_CHECKS[option])[configuration[option]] end end end end # Creates an object just like Base.create but calls save! instead of save # so an exception is raised if the record is invalid. 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 private def validation_method(on) case on when :save then :validate when :create then :validate_on_create when :update then :validate_on_update end end end # The validation process on save can be skipped by passing false. The regular Base#save method is # replaced with this when the validations module is mixed in, which it is by default. def save_with_validation(perform_validation = true) if perform_validation && valid? || !perform_validation save_without_validation else false end end # Attempts to save the record just like Base#save but will raise a RecordInvalid exception instead of returning false # if the record is not valid. def save_with_validation! if valid? save_without_validation! else raise RecordInvalid.new(self) end end # Runs +validate+ and +validate_on_create+ or +validate_on_update+ and returns true if no errors were added otherwise false. def valid? errors.clear run_callbacks(:validate) validate if new_record? run_callbacks(:validate_on_create) validate_on_create else run_callbacks(:validate_on_update) validate_on_update end errors.empty? end # Returns the Errors object that holds all information about attribute error messages. def errors @errors ||= Errors.new(self) end protected # Overwrite this method for validation checks on all saves and use Errors.add(field, msg) for invalid attributes. def validate #:doc: end # Overwrite this method for validation checks used only on creation. def validate_on_create #:doc: end # Overwrite this method for validation checks used only on updates. def validate_on_update # :doc: end end end