rails/activemodel/lib/active_model/validations.rb

210 lines
7.0 KiB
Ruby

require 'active_support/core_ext/array/extract_options'
require 'active_support/core_ext/array/wrap'
require 'active_support/core_ext/class/attribute'
require 'active_support/core_ext/hash/keys'
require 'active_support/core_ext/hash/except'
require 'active_model/errors'
require 'active_model/validations/callbacks'
module ActiveModel
# == Active Model Validations
#
# Provides a full validation framework to your objects.
#
# A minimal implementation could be:
#
# class Person
# include ActiveModel::Validations
#
# attr_accessor :first_name, :last_name
#
# validates_each :first_name, :last_name do |record, attr, value|
# record.errors.add attr, 'starts with z.' if value.to_s[0] == ?z
# end
# end
#
# Which provides you with the full standard validation stack that you
# know from Active Record:
#
# person = Person.new
# person.valid? # => true
# person.invalid? # => false
#
# person.first_name = 'zoolander'
# person.valid? # => false
# person.invalid? # => true
# person.errors # => #<OrderedHash {:first_name=>["starts with z."]}>
#
# Note that ActiveModel::Validations automatically adds an +errors+ method
# to your instances initialized with a new ActiveModel::Errors object, so
# there is no need for you to do this manually.
#
module Validations
extend ActiveSupport::Concern
include ActiveSupport::Callbacks
included do
extend ActiveModel::Translation
extend HelperMethods
include HelperMethods
attr_accessor :validation_context
define_callbacks :validate, :scope => :name
class_attribute :_validators
self._validators = Hash.new { |h,k| h[k] = [] }
end
module ClassMethods
# Validates each attribute against a block.
#
# class Person
# include ActiveModel::Validations
#
# attr_accessor :first_name, :last_name
#
# validates_each :first_name, :last_name do |record, attr, value|
# record.errors.add attr, 'starts with z.' if value.to_s[0] == ?z
# end
# end
#
# Options:
# * <tt>:on</tt> - Specifies when this validation is active (default is
# <tt>:save</tt>, other options <tt>:create</tt>, <tt>:update</tt>).
# * <tt>:allow_nil</tt> - Skip validation if attribute is +nil+.
# * <tt>:allow_blank</tt> - Skip validation if attribute is blank.
# * <tt>:if</tt> - Specifies a method, proc or string to call to determine
# if the validation should occur (e.g. <tt>:if => :allow_validation</tt>,
# or <tt>:if => Proc.new { |user| user.signup_step > 2 }</tt>). The method,
# proc or string should return or evaluate to a true or false value.
# * <tt>:unless</tt> - Specifies a method, proc or string to call to determine if the validation should
# not occur (e.g. <tt>:unless => :skip_validation</tt>, or
# <tt>:unless => Proc.new { |user| user.signup_step <= 2 }</tt>). The
# method, proc or string should return or evaluate to a true or false value.
def validates_each(*attr_names, &block)
options = attr_names.extract_options!.symbolize_keys
validates_with BlockValidator, options.merge(:attributes => attr_names.flatten), &block
end
# Adds a validation method or block to the class. This is useful when
# overriding the +validate+ instance method becomes too unwieldy and
# you're looking for more descriptive declaration of your validations.
#
# This can be done with a symbol pointing to a method:
#
# class Comment
# include ActiveModel::Validations
#
# validate :must_be_friends
#
# def must_be_friends
# errors.add(:base, "Must be friends to leave a comment") unless commenter.friend_of?(commentee)
# end
# end
#
# Or with a block which is passed with the current record to be validated:
#
# class Comment
# include ActiveModel::Validations
#
# validate do |comment|
# comment.must_be_friends
# end
#
# def must_be_friends
# errors.add(:base, "Must be friends to leave a comment") unless commenter.friend_of?(commentee)
# end
# end
#
def validate(*args, &block)
options = args.extract_options!
if options.key?(:on)
options = options.dup
options[:if] = Array.wrap(options[:if])
options[:if] << "validation_context == :#{options[:on]}"
end
args << options
set_callback(:validate, *args, &block)
end
# List all validators that are being used to validate the model using
# +validates_with+ method.
def validators
_validators.values.flatten.uniq
end
# List all validators that being used to validate a specific attribute.
def validators_on(attribute)
_validators[attribute.to_sym]
end
# Check if method is an attribute method or not.
def attribute_method?(attribute)
method_defined?(attribute)
end
# Copy validators on inheritance.
def inherited(base)
dup = _validators.dup
base._validators = dup.each { |k, v| dup[k] = v.dup }
super
end
end
# Returns the Errors object that holds all information about attribute error messages.
def errors
@errors ||= Errors.new(self)
end
# Runs all the specified validations and returns true if no errors were added
# otherwise false. Context can optionally be supplied to define which callbacks
# to test against (the context is defined on the validations using :on).
def valid?(context = nil)
current_context, self.validation_context = validation_context, context
errors.clear
run_validations!
ensure
self.validation_context = current_context
end
# Performs the opposite of <tt>valid?</tt>. Returns true if errors were added,
# false otherwise.
def invalid?(context = nil)
!valid?(context)
end
# Hook method defining how an attribute value should be retrieved. By default
# this is assumed to be an instance named after the attribute. Override this
# method in subclasses should you need to retrieve the value for a given
# attribute differently:
#
# class MyClass
# include ActiveModel::Validations
#
# def initialize(data = {})
# @data = data
# end
#
# def read_attribute_for_validation(key)
# @data[key]
# end
# end
#
alias :read_attribute_for_validation :send
protected
def run_validations!
_run_validate_callbacks
errors.empty?
end
end
end
Dir[File.dirname(__FILE__) + "/validations/*.rb"].sort.each do |path|
filename = File.basename(path)
require "active_model/validations/#{filename}"
end