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rails--rails/activerecord/lib/active_record/validations.rb

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Ruby
Executable file

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 #:nodoc:
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 in a valid state to be saved. See usage example in Validations.
class Errors
include Enumerable
def initialize(base) # :nodoc:
@base, @errors = base, {}
end
@@default_error_messages = {
:inclusion => "is not included in the list",
:exclusion => "is reserved",
:invalid => "is invalid",
:confirmation => "doesn't match confirmation",
:accepted => "must be accepted",
:empty => "can't be empty",
:blank => "can't be blank",
:too_long => "is too long (maximum is %d characters)",
:too_short => "is too short (minimum is %d characters)",
:wrong_length => "is the wrong length (should be %d characters)",
:taken => "has already been taken",
:not_a_number => "is not a number"
}
# Holds a hash with all the default error messages, such that they can be replaced by your own copy or localizations.
cattr_accessor :default_error_messages
# 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 (+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 <tt>empty?</tt>. 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.
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 is blank (using Object#blank?).
def add_on_blank(attributes, msg = @@default_error_messages[:blank])
for attr in [attributes].flatten
value = @base.respond_to?(attr.to_s) ? @base.send(attr.to_s) : @base[attr.to_s]
add(attr, msg) if value.blank?
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)
errors = @errors[attribute.to_s]
return nil if errors.nil?
errors.size == 1 ? errors.first : errors
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
full_messages
end
# Returns true if no errors have been added.
def empty?
@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 size
@errors.values.inject(0) { |error_count, attribute| error_count + attribute.size }
end
alias_method :count, :size
alias_method :length, :size
# Return an XML representation of this error object.
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
# 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.
#
# 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.included(base) # :nodoc:
base.extend ClassMethods
base.class_eval do
alias_method_chain :save, :validation
alias_method_chain :save!, :validation
alias_method_chain :update_attribute, :validation_skipping
end
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
DEFAULT_VALIDATION_OPTIONS = {
:on => :save,
:allow_nil => false,
:message => nil
}.freeze
ALL_RANGE_OPTIONS = [ :is, :within, :in, :minimum, :maximum ].freeze
def validate(*methods, &block)
methods << block if block_given?
write_inheritable_set(:validate, methods)
end
def validate_on_create(*methods, &block)
methods << block if block_given?
write_inheritable_set(:validate_on_create, methods)
end
def validate_on_update(*methods, &block)
methods << block if block_given?
write_inheritable_set(:validate_on_update, methods)
end
def condition_block?(condition)
condition.respond_to?("call") && (condition.arity == 1 || condition.arity == -1)
end
# Determine from the given condition (whether a block, procedure, method or string)
# whether or not to validate the record. See #validates_each.
def evaluate_condition(condition, record)
case condition
when Symbol: record.send(condition)
when String: eval(condition, binding)
else
if condition_block?(condition)
condition.call(record)
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
# 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:
# * <tt>on</tt> - Specifies when this validation is active (default is :save, other options :create, :update)
# * <tt>allow_nil</tt> - Skip validation if attribute is nil.
# * <tt>if</tt> - 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.
def validates_each(*attrs)
options = attrs.last.is_a?(Hash) ? attrs.pop.symbolize_keys : {}
attrs = attrs.flatten
# Declare the validation.
send(validation_method(options[:on] || :save)) do |record|
# Don't validate when there is an :if condition and that condition is false
unless options[:if] && !evaluate_condition(options[:if], record)
attrs.each do |attr|
value = record.send(attr)
next if value.nil? && options[:allow_nil]
yield record, attr, value
end
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 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:
# * <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)
# * <tt>if</tt> - 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.
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)
attr_accessor *(attr_names.map { |n| "#{n}_confirmation" })
validates_each(attr_names, configuration) do |record, attr_name, value|
confirm = record.send("#{attr_name}_confirmation")
record.errors.add(attr_name, configuration[:message]) unless value.nil? || value == confirm
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:
# * <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)
# * <tt>accept</tt> - Specifies value that is considered accepted. The default value is a string "1", which
# makes it easy to relate to an HTML checkbox.
# * <tt>if</tt> - 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.
def validates_acceptance_of(*attr_names)
configuration = { :message => ActiveRecord::Errors.default_error_messages[:accepted], :on => :save, :allow_nil => true, :accept => "1" }
configuration.update(attr_names.pop) if attr_names.last.is_a?(Hash)
attr_accessor *attr_names
validates_each(attr_names,configuration) do |record, attr_name, value|
record.errors.add(attr_name, configuration[:message]) unless value == configuration[:accept]
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.
#
# Configuration options:
# * <tt>message</tt> - A custom error message (default is: "can't be blank")
# * <tt>on</tt> - Specifies when this validation is active (default is :save, other options :create, :update)
# * <tt>if</tt> - 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.
#
# === Warning
# Validate the presence of the foreign key, not the instance variable itself.
# Do this:
# validate_presence_of :invoice_id
#
# Not this:
# validate_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.
def validates_presence_of(*attr_names)
configuration = { :message => ActiveRecord::Errors.default_error_messages[:blank], :on => :save }
configuration.update(attr_names.pop) if attr_names.last.is_a?(Hash)
# can't use validates_each here, because it cannot cope with nonexistent attributes,
# while errors.add_on_empty can
attr_names.each do |attr_name|
send(validation_method(configuration[:on])) do |record|
unless configuration[:if] and not evaluate_condition(configuration[:if], record)
record.errors.add_on_blank(attr_name,configuration[:message])
end
end
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 :fax, :in => 7..32, :allow_nil => 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:
# * <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>allow_nil</tt> - Attribute may be nil; skip validation.
#
# * <tt>too_long</tt> - The error message if the attribute goes over the maximum (default is: "is too long (maximum 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)
# * <tt>if</tt> - 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.
def validates_length_of(*attrs)
# Merge given options with defaults.
options = {
: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]
}.merge(DEFAULT_VALIDATION_OPTIONS)
options.update(attrs.pop.symbolize_keys) if attrs.last.is_a?(Hash)
# 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)
too_short = options[:too_short] % option_value.begin
too_long = options[:too_long] % option_value.end
validates_each(attrs, options) do |record, attr, value|
if value.nil? or value.split(//).size < option_value.begin
record.errors.add(attr, too_short)
elsif value.split(//).size > option_value.end
record.errors.add(attr, too_long)
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 }
message = (options[:message] || options[message_options[option]]) % option_value
validates_each(attrs, options) do |record, attr, value|
if value.kind_of?(String)
record.errors.add(attr, message) unless !value.nil? and value.split(//).size.method(validity_checks[option])[option_value]
else
record.errors.add(attr, message) unless !value.nil? and value.size.method(validity_checks[option])[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:
# * <tt>message</tt> - Specifies a custom error message (default is: "has already been taken")
# * <tt>scope</tt> - One or more columns by which to limit the scope of the uniquness constraint.
# * <tt>case_sensitive</tt> - Looks for an exact match. Ignored by non-text columns (true by default).
# * <tt>if</tt> - 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.
def validates_uniqueness_of(*attr_names)
configuration = { :message => ActiveRecord::Errors.default_error_messages[:taken], :case_sensitive => true }
configuration.update(attr_names.pop) if attr_names.last.is_a?(Hash)
validates_each(attr_names,configuration) do |record, attr_name, value|
if value.nil? || (configuration[:case_sensitive] || !columns_hash[attr_name.to_s].text?)
condition_sql = "#{record.class.table_name}.#{attr_name} #{attribute_condition(value)}"
condition_params = [value]
else
condition_sql = "UPPER(#{record.class.table_name}.#{attr_name}) #{attribute_condition(value)}"
condition_params = [value.upcase]
end
if scope = configuration[:scope]
Array(scope).map do |scope_item|
scope_value = record.send(scope_item)
condition_sql << " AND #{record.class.table_name}.#{scope_item} #{attribute_condition(scope_value)}"
condition_params << scope_value
end
end
unless record.new_record?
condition_sql << " AND #{record.class.table_name}.#{record.class.primary_key} <> ?"
condition_params << record.send(:id)
end
if record.class.find(:first, :conditions => [condition_sql, *condition_params])
record.errors.add(attr_name, configuration[:message])
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,})$/i, :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)
# * <tt>if</tt> - 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.
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)
validates_each(attr_names, configuration) do |record, attr_name, value|
record.errors.add(attr_name, configuration[:message]) unless value.to_s =~ 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> - Specifies a customer error message (default is: "is not included in the list")
# * <tt>allow_nil</tt> - If set to true, skips this validation if the attribute is null (default is: false)
# * <tt>if</tt> - 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.
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?")
validates_each(attr_names, configuration) do |record, attr_name, value|
record.errors.add(attr_name, configuration[:message]) unless enum.include?(value)
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"
# end
#
# Configuration options:
# * <tt>in</tt> - An enumerable object of items that the value shouldn't be part of
# * <tt>message</tt> - Specifies a customer error message (default is: "is reserved")
# * <tt>allow_nil</tt> - If set to true, skips this validation if the attribute is null (default is: false)
# * <tt>if</tt> - 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.
def validates_exclusion_of(*attr_names)
configuration = { :message => ActiveRecord::Errors.default_error_messages[:exclusion], :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?")
validates_each(attr_names, configuration) do |record, attr_name, value|
record.errors.add(attr_name, configuration[:message]) if enum.include?(value)
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:
# * <tt>on</tt> Specifies when this validation is active (default is :save, other options :create, :update)
# * <tt>if</tt> - 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.
def validates_associated(*attr_names)
configuration = { :message => ActiveRecord::Errors.default_error_messages[:invalid], :on => :save }
configuration.update(attr_names.pop) if attr_names.last.is_a?(Hash)
validates_each(attr_names, configuration) do |record, attr_name, value|
record.errors.add(attr_name, configuration[:message]) unless
(value.is_a?(Array) ? value : [value]).all? { |r| r.nil? or r.valid? }
end
end
# Validates whether the value of the specified attribute is numeric by trying to convert it to
# a float with Kernel.Float (if <tt>integer</tt> is false) or applying it to the regular expression
# <tt>/^[\+\-]?\d+$/</tt> (if <tt>integer</tt> is set to true).
#
# class Person < ActiveRecord::Base
# validates_numericality_of :value, :on => :create
# end
#
# Configuration options:
# * <tt>message</tt> - A custom error message (default is: "is not a number")
# * <tt>on</tt> Specifies when this validation is active (default is :save, other options :create, :update)
# * <tt>only_integer</tt> Specifies whether the value has to be an integer, e.g. an integral value (default is false)
# * <tt>allow_nil</tt> Skip validation if attribute is nil (default is false). Notice that for fixnum and float columns empty strings are converted to nil
# * <tt>if</tt> - 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.
def validates_numericality_of(*attr_names)
configuration = { :message => ActiveRecord::Errors.default_error_messages[:not_a_number], :on => :save,
:only_integer => false, :allow_nil => false }
configuration.update(attr_names.pop) if attr_names.last.is_a?(Hash)
if configuration[:only_integer]
validates_each(attr_names,configuration) do |record, attr_name,value|
record.errors.add(attr_name, configuration[:message]) unless record.send("#{attr_name}_before_type_cast").to_s =~ /^[+-]?\d+$/
end
else
validates_each(attr_names,configuration) do |record, attr_name,value|
next if configuration[:allow_nil] and record.send("#{attr_name}_before_type_cast").nil?
begin
Kernel.Float(record.send("#{attr_name}_before_type_cast").to_s)
rescue ArgumentError, TypeError
record.errors.add(attr_name, configuration[:message])
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)
if attributes.is_a?(Array)
attributes.collect { |attr| create!(attr) }
else
attributes ||= {}
attributes.reverse_merge!(scope(:create)) if scoped?(:create)
object = new(attributes)
object.save!
object
end
end
private
def write_inheritable_set(key, methods)
existing_methods = read_inheritable_attribute(key) || []
write_inheritable_attribute(key, methods | existing_methods)
end
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
# 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)
send(name.to_s + '=', 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)
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_sym)
if validations.nil? then return end
validations.each do |validation|
if validation.is_a?(Symbol)
self.send(validation)
elsif validation.is_a?(String)
eval(validation, binding)
elsif validation_block?(validation)
validation.call(self)
elsif validation_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
end