module ActiveRecord # 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 occured") 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.count # => 2 # person.errors.on "last_name" # => "can't be empty" # person.errors.on "phone_number" # => "has invalid format" # person.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. # # Please do have a look at ActiveRecord::Validations::ClassMethods for a higher level of validations. module Validations VALIDATIONS = %w( validate validate_on_create validate_on_update ) def self.append_features(base) # :nodoc: super base.class_eval do alias_method :save_without_validation, :save alias_method :save, :save_with_validation alias_method :update_attribute_without_validation_skipping, :update_attribute alias_method :update_attribute, :update_attribute_with_validation_skipping VALIDATIONS.each { |vd| base.class_eval("def self.#{vd}(*methods) write_inheritable_array(\"#{vd}\", methods - (read_inheritable_attribute(\"#{vd}\") || [])) end") } end base.extend(ClassMethods) end # 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. module ClassMethods # 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 person has to already have a password attribute (a column in the people table), but the password_confirmation is virtual. # It exists only as an in-memory variable for validating the password. This check is performed only if password_confirmation # is not nil and by default on save. # # 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) def validates_confirmation_of(*attr_names) configuration = { :message => ActiveRecord::Errors.default_error_messages[:confirmation], :on => :save } configuration.update(attr_names.pop) if attr_names.last.is_a?(Hash) for attr_name in attr_names attr_accessor "#{attr_name}_confirmation" class_eval(%(#{validation_method(configuration[:on])} %{errors.add('#{attr_name}', "#{configuration[:message]}") unless #{attr_name}_confirmation.nil? or #{attr_name} == #{attr_name}_confirmation})) 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 # # The terms_of_service attribute is entirely virtual. No database column is needed. 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: "can't be empty") # * on - Specifies when this validation is active (default is :save, other options :create, :update) # # NOTE: The agreement is considered valid if it's set to the string "1". This makes it easy to relate it to an HTML checkbox. def validates_acceptance_of(*attr_names) configuration = { :message => ActiveRecord::Errors.default_error_messages[:accepted], :on => :save } configuration.update(attr_names.pop) if attr_names.last.is_a?(Hash) for attr_name in attr_names attr_accessor(attr_name) class_eval(%(#{validation_method(configuration[:on])} %{errors.add('#{attr_name}', '#{configuration[:message]}') unless #{attr_name}.nil? or #{attr_name} == "1"})) end end # Validates that the specified attributes are neither nil nor empty. Happens by default on save. # # Configuration options: # * message - A custom error message (default is: "has already been taken") # * on - Specifies when this validation is active (default is :save, other options :create, :update) def validates_presence_of(*attr_names) configuration = { :message => ActiveRecord::Errors.default_error_messages[:empty], :on => :save } configuration.update(attr_names.pop) if attr_names.last.is_a?(Hash) for attr_name in attr_names class_eval(%(#{validation_method(configuration[:on])} %{errors.add_on_empty('#{attr_name}', "#{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 %d if you don't mind" # 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 # # * too_long - The error message if the attribute goes over the maximum (default is: "is too long (max 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) def validates_length_of(*attr_names) configuration = { :too_long => ActiveRecord::Errors.default_error_messages[:too_long], :too_short => ActiveRecord::Errors.default_error_messages[:too_short], :wrong_length => ActiveRecord::Errors.default_error_messages[:wrong_length], :on => :save } configuration.update(attr_names.pop) if attr_names.last.is_a?(Hash) # you must use one of 4 options, :within, :maximum, :minimum, or :is within = configuration[:within] || configuration[:in] maximum = configuration[:maximum] minimum = configuration[:minimum] is = configuration[:is] raise(ArgumentError, "The :within, :maximum, :minimum, or :is options must be passed in the configuration hash") unless within or maximum or minimum or is # but not more than 1 of them at a time options_used = 0 options_used += 1 if within options_used += 1 if maximum options_used += 1 if minimum options_used += 1 if is raise(ArgumentError, "The :within, :maximum, :minimum, and :is options are mutually exclusive") if options_used > 1 option_to_use = within || maximum || minimum || is for attr_name in attr_names if within raise(ArgumentError, "The :within option must be a Range") unless within.kind_of?(Range) class_eval(%(#{validation_method(configuration[:on])} %{errors.add_on_boundary_breaking('#{attr_name}', #{within}, "#{configuration[:too_long]}", "#{configuration[:too_short]}")})) elsif maximum raise(ArgumentError, "The :maximum option must be a Fixnum") unless maximum.kind_of?(Fixnum) msg = configuration[:message] || configuration[:too_long] msg = (msg % maximum) rescue msg class_eval(%(#{validation_method(configuration[:on])} %{errors.add( '#{attr_name}', '#{msg}') if #{attr_name}.to_s.length > #{maximum} })) elsif minimum raise(ArgumentError, "The :minimum option must be a Fixnum") unless minimum.kind_of?(Fixnum) msg = configuration[:message] || configuration[:too_short] msg = (msg % minimum) rescue msg class_eval(%(#{validation_method(configuration[:on])} %{errors.add( '#{attr_name}', '#{msg}') if #{attr_name}.to_s.length < #{minimum} })) else raise(ArgumentError, "The :is option must be a Fixnum") unless is.kind_of?(Fixnum) msg = configuration[:message] || configuration[:wrong_length] msg = (msg % is) rescue msg class_eval(%(#{validation_method(configuration[:on])} %{errors.add( '#{attr_name}', '#{msg}') if #{attr_name}.to_s.length != #{is} })) end end 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 # # When the record is created, a check is performed to make sure that no record exist 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 - Ensures that the uniqueness is restricted to a condition of "scope = record.scope" def validates_uniqueness_of(*attr_names) configuration = { :message => ActiveRecord::Errors.default_error_messages[:taken] } configuration.update(attr_names.pop) if attr_names.last.is_a?(Hash) for attr_name in attr_names if scope = configuration[:scope] class_eval(%(validate %{errors.add('#{attr_name}', '#{configuration[:message]}') if self.class.find_first(new_record? ? ['#{attr_name} = ? AND #{scope} = ?', #{attr_name}, #{scope}] : ["#{attr_name} = ? AND \\\#{self.class.primary_key} <> ? AND #{scope} = ?", #{attr_name}, id, #{scope}])})) else class_eval(%(validate %{errors.add('#{attr_name}', '#{configuration[:message]}') if self.class.find_first(new_record? ? ['#{attr_name} = ?', #{attr_name}] : ["#{attr_name} = ? AND \\\#{self.class.primary_key} <> ?", #{attr_name}, id])})) 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 => /^([^@\s]+)@((?:[-a-z0-9]+\.)+[a-z]{2,})$/, :on => :create # end # # 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) def validates_format_of(*attr_names) configuration = { :message => ActiveRecord::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) for attr_name in attr_names class_eval(%(#{validation_method(configuration[:on])} %{errors.add("#{attr_name}", "#{configuration[:message]}") unless #{attr_name} and #{attr_name}.to_s.match(/#{Regexp.quote(configuration[:with].source)}/)})) 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 # end # # Configuration options: # * in - An enumerable object of available items # * message - Specifieds a customer error message (default is: "is not included in the list") # * allows_nil - If set to true, skips this validation if the attribute is null (default is: false) def validates_inclusion_of(*attr_names) configuration = { :message => ActiveRecord::Errors.default_error_messages[:inclusion], :on => :save } configuration.update(attr_names.pop) if attr_names.last.is_a?(Hash) enum = configuration[:in] || configuration[:within] allow_nil = configuration[:allow_nil] 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?") for attr_name in attr_names if allow_nil class_eval(%(#{validation_method(configuration[:on])} %{errors.add("#{attr_name}", "#{configuration[:message]}") unless #{attr_name}.nil? or (#{enum.inspect}).include?(#{attr_name}) })) else class_eval(%(#{validation_method(configuration[:on])} %{errors.add("#{attr_name}", "#{configuration[:message]}") unless (#{enum.inspect}).include?(#{attr_name}) })) end 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 then save_without_validation else false end end # Updates a single attribute and saves the record without going through the normal validation procedure. # This is especially useful for boolean flags on existing records. The regular +update_attribute+ method # in Base is replaced with this when the validations module is mixed in, which it is by default. def update_attribute_with_validation_skipping(name, value) @attributes[name] = value save(false) 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_validations(:validate) validate if new_record? run_validations(:validate_on_create) validate_on_create else run_validations(: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) if @errors.nil? @errors 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 private def run_validations(validation_method) validations = self.class.read_inheritable_attribute(validation_method.to_s) if validations.nil? then return end validations.each do |validation| if Symbol === validation self.send(validation) elsif String === validation eval(validation, binding) elsif validation_block?(validation) validation.call(self) elsif filter_class?(validation, validation_method) validation.send(validation_method, self) else raise( ActiveRecordError, "Validations need to be either a symbol, string (to be eval'ed), proc/method, or " + "class implementing a static validation method" ) end end end def validation_block?(validation) validation.respond_to?("call") && (validation.arity == 1 || validation.arity == -1) end def validation_class?(validation, validation_method) validation.respond_to?(validation_method) end end # Active Record validation is reported to and from this object, which is used by Base#save to # determine whether the object in a valid state to be saved. See usage example in Validations. class Errors def initialize(base) # :nodoc: @base, @errors = base, {} end @@default_error_messages = { :inclusion => "is not included in the list", :invalid => "is invalid", :confirmation => "doesn't match confirmation", :accepted => "must be accepted", :empty => "can't be empty", :too_long => "is too long (max is %d characters)", :too_short => "is too short (min is %d characters)", :wrong_length => "is the wrong length (should be %d characters)", :taken => "has already been taken", } cattr_accessor :default_error_messages # Adds an error to the base object instead of any particular attribute. This is used # to report errors that doesn't tie to any specific attribute, but rather to the object # as a whole. These error messages doesn'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 (+msg+) 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 +msg+ is supplied, "invalid" is assumed. def add(attribute, msg = @@default_error_messages[:invalid]) @errors[attribute.to_s] = [] if @errors[attribute.to_s].nil? @errors[attribute.to_s] << msg end # Will add an error message to each of the attributes in +attributes+ that is empty (defined by attribute_present?). def add_on_empty(attributes, msg = @@default_error_messages[:empty]) 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, msg) unless !value.nil? && !is_empty end end # Will add an error message to each of the attributes in +attributes+ that has a length outside of the passed boundary +range+. # If the length is above the boundary, the too_long_msg message will be used. If below, the too_short_msg. def add_on_boundary_breaking(attributes, range, too_long_msg = @@default_error_messages[:too_long], too_short_msg = @@default_error_messages[:too_short]) for attr in [attributes].flatten value = @base.respond_to?(attr.to_s) ? @base.send(attr.to_s) : @base[attr.to_s] add(attr, too_short_msg % range.begin) if value && value.length < range.begin add(attr, too_long_msg % range.end) if value && value.length > range.end end end alias :add_on_boundry_breaking :add_on_boundary_breaking # Returns true if the specified +attribute+ has errors associated with it. 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+. def on(attribute) if @errors[attribute.to_s].nil? nil elsif @errors[attribute.to_s].length == 1 @errors[attribute.to_s].first else @errors[attribute.to_s] end end alias :[] :on # Returns errors assigned to 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. 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". def each_full full_messages.each { |msg| yield msg } end # Returns all the full error messages in an array. def full_messages full_messages = [] @errors.each_key do |attr| @errors[attr].each do |msg| next if msg.nil? if attr == "base" full_messages << msg else full_messages << @base.class.human_attribute_name(attr) + " " + msg end end end return full_messages end # Returns true if no errors have been added. def empty? return @errors.empty? end # Removes all the 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 # with this as well. def count error_count = 0 @errors.each_value { |attribute| error_count += attribute.length } error_count end end end