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 both on create and update.
#
# Configuration options:
# * <tt>message</tt> - A custom error message (default is: "doesn't match confirmation")
# * <tt>on</tt> - 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} == #{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 both on create and update.
#
# Configuration options:
# * <tt>message</tt> - A custom error message (default is: "must be accepted")
# * <tt>on</tt> - 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} == "1"}))
end
end
# Validates that the specified attributes are neither nil nor empty. Happens by default on both create and update.
#
# Configuration options:
# * <tt>message</tt> - A custom error message (default is: "has already been taken")
# * <tt>on</tt> - 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:
# * <tt>minimum</tt> - The minimum size of the attribute
# * <tt>maximum</tt> - The maximum size of the attribute
# * <tt>is</tt> - The exact size of the attribute
# * <tt>within</tt> - A range specifying the minimum and maximum size of the attribute
# * <tt>in</tt> - A synonym(or alias) for :within
#
# * <tt>too_long</tt> - The error message if the attribute goes over the maximum (default is: "is too long (max is %d characters)")
# * <tt>too_short</tt> - The error message if the attribute goes under the minimum (default is: "is too short (min is %d characters)")
# * <tt>wrong_length</tt> - 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)")
# * <tt>message</tt> - The error message to use for a :minimum, :maximum, or :is violation. An alias of the appropriate too_long/too_short/wrong_length message
# * <tt>on</tt> - 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
# 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:
# * <tt>message</tt> - Specifies a custom error message (default is: "has already been taken")
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
class_eval(%(validate %{errors.add("#{attr_name}", "#{configuration[:message]}") if self.class.find_first(new_record? ? ["#{attr_name} = ?", #{attr_name}] : ["#{attr_name} = ? AND id <> ?", #{attr_name}, id])}))
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:
# * <tt>message</tt> - A custom error message (default is: "is invalid")
# * <tt>with</tt> - The regular expression used to validate the format with (note: must be supplied!)
# * <tt>on</tt> 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(/#{configuration[:with]}/)}))
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:
# * <tt>in</tt> - An enumerable object of available items
# * <tt>message</tt> - Specifieds a customer error message (default is: "is not included in the list")
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]
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
class_eval(%(#{validation_method(configuration[:on])} %{errors.add("#{attr_name}", "#{configuration[:message]}") unless (#{enum.inspect}).include?(#{attr_name}) }))
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 <tt>on(attribute)</tt>
# 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 <tt>on(attribute)</tt>.
# 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 <tt>attribute_present?</tt>).
def add_on_empty(attributes, msg = @@default_error_messages[:empty])
[attributes].flatten.each { |attr| add(attr, msg) unless @base.attribute_present?(attr.to_s) }
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
add(attr, too_short_msg % range.begin) if @base.attribute_present?(attr.to_s) && @base.send(attr.to_s).length < range.begin
add(attr, too_long_msg % range.end) if @base.attribute_present?(attr.to_s) && @base.send(attr.to_s).length > range.end
end
end
alias :add_on_boundary_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