From 9feda929409ab687befaed8d1c9878d94e955adc Mon Sep 17 00:00:00 2001 From: Brent Wheeldon & Nick Monje Date: Fri, 22 Jun 2012 12:09:48 -0400 Subject: [PATCH] AR has a subclass of AM:PresenceValidator. This allows us to mark the parent object as invalid if all associated objects in a presence validated association are marked for destruction. See: https://github.com/rails/rails/issues/6812 --- activerecord/CHANGELOG.md | 7 ++ activerecord/lib/active_record/validations.rb | 1 + .../lib/active_record/validations/presence.rb | 64 +++++++++++++++++++ .../validations/presence_validation_test.rb | 44 +++++++++++++ ...ctive_record_validations_callbacks.textile | 2 + 5 files changed, 118 insertions(+) create mode 100644 activerecord/lib/active_record/validations/presence.rb create mode 100644 activerecord/test/cases/validations/presence_validation_test.rb diff --git a/activerecord/CHANGELOG.md b/activerecord/CHANGELOG.md index a965fe04944eb..f41ccfe56f57f 100644 --- a/activerecord/CHANGELOG.md +++ b/activerecord/CHANGELOG.md @@ -31,6 +31,13 @@ *kennyj* +* Changed validates_presence_of on an association so that children objects + do not validate as being present if they are marked for destruction. This + prevents you from saving the parent successfully and thus putting the parent + in an invalid state. + + *Nick Monje & Brent Wheeldon* + * `FinderMethods#exists?` now returns `false` with the `false` argument. *Egor Lynko* diff --git a/activerecord/lib/active_record/validations.rb b/activerecord/lib/active_record/validations.rb index d06020b3ce9c1..cef2bbd563389 100644 --- a/activerecord/lib/active_record/validations.rb +++ b/activerecord/lib/active_record/validations.rb @@ -81,3 +81,4 @@ def perform_validations(options={}) require "active_record/validations/associated" require "active_record/validations/uniqueness" +require "active_record/validations/presence" diff --git a/activerecord/lib/active_record/validations/presence.rb b/activerecord/lib/active_record/validations/presence.rb new file mode 100644 index 0000000000000..056527b512579 --- /dev/null +++ b/activerecord/lib/active_record/validations/presence.rb @@ -0,0 +1,64 @@ +module ActiveRecord + module Validations + class PresenceValidator < ActiveModel::Validations::PresenceValidator + def validate(record) + super + attributes.each do |attribute| + next unless record.class.reflect_on_association(attribute) + value = record.send(attribute) + if Array(value).all? { |r| r.marked_for_destruction? } + record.errors.add(attribute, :blank, options) + end + end + end + end + + module ClassMethods + # Validates that the specified attributes are not blank (as defined by + # Object#blank?), and, if the attribute is an association, that the + # associated object is not marked for destruction. Happens by default + # on save. + # + # class Person < ActiveRecord::Base + # has_one :face + # validates_presence_of :face + # end + # + # The face attribute must be in the object and it cannot be blank or marked + # for destruction. + # + # 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. + # + # This validator defers to the ActiveModel validation for presence, adding the + # check to see that an associated object is not marked for destruction. This + # prevents the parent object from validating successfully and saving, which then + # deletes the associated object, thus putting the parent object into an invalid + # state. + # + # Configuration options: + # * :message - A custom error message (default is: "can't be blank"). + # * :on - Specifies when this validation is active. Runs in all + # validation contexts by default (+nil+), other options are :create + # and :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. + # * :strict - Specifies whether validation should be strict. + # See ActiveModel::Validation#validates! for more information. + # + def validates_presence_of(*attr_names) + validates_with PresenceValidator, _merge_attributes(attr_names) + end + end + end +end diff --git a/activerecord/test/cases/validations/presence_validation_test.rb b/activerecord/test/cases/validations/presence_validation_test.rb new file mode 100644 index 0000000000000..cd9175f45479b --- /dev/null +++ b/activerecord/test/cases/validations/presence_validation_test.rb @@ -0,0 +1,44 @@ +# encoding: utf-8 +require "cases/helper" +require 'models/man' +require 'models/face' +require 'models/interest' + +class PresenceValidationTest < ActiveRecord::TestCase + class Boy < Man; end + + repair_validations(Boy) + + def test_validates_presence_of_non_association + Boy.validates_presence_of(:name) + b = Boy.new + assert b.invalid? + + b.name = "Alex" + assert b.valid? + end + + def test_validates_presence_of_has_one_marked_for_destruction + Boy.validates_presence_of(:face) + b = Boy.new + f = Face.new + b.face = f + assert b.valid? + + f.mark_for_destruction + assert b.invalid? + end + + def test_validates_presence_of_has_many_marked_for_destruction + Boy.validates_presence_of(:interests) + b = Boy.new + b.interests << [i1 = Interest.new, i2 = Interest.new] + assert b.valid? + + i1.mark_for_destruction + assert b.valid? + + i2.mark_for_destruction + assert b.invalid? + end +end diff --git a/guides/source/active_record_validations_callbacks.textile b/guides/source/active_record_validations_callbacks.textile index f49d91fd3c28b..da3a96d84ed9b 100644 --- a/guides/source/active_record_validations_callbacks.textile +++ b/guides/source/active_record_validations_callbacks.textile @@ -373,6 +373,8 @@ class LineItem < ActiveRecord::Base end +If you validate the presence of an object associated via a +has_one+ or +has_many+ relationship, it will check that the object is neither +blank?+ nor +marked_for_destruction?+. + Since +false.blank?+ is true, if you want to validate the presence of a boolean field you should use validates :field_name, :inclusion => { :in => [true, false] }. The default error message is "_can't be empty_".