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Add :dependent = to has_one and has_many [#3075 state:resolved]

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1 parent 76f024a commit f1e5a9ff982998c31c9dedf2fa79180c7dea820a @rizwanreza rizwanreza committed Mar 28, 2010
@@ -86,6 +86,15 @@ def initialize(reflection)
end
end
+ # This error is raised when trying to destroy a parent instance in a N:1, 1:1 assosications
+ # (has_many, has_one) when there is at least 1 child assosociated instance.
+ # ex: if @project.tasks.size > 0, DeleteRestrictionError will be raised when trying to destroy @project
+ class DeleteRestrictionError < ActiveRecordError #:nodoc:
+ def initialize(reflection)
+ super("Cannot delete record because of dependent #{reflection.name}")
+ end
+ end
+
# See ActiveRecord::Associations::ClassMethods for documentation.
module Associations # :nodoc:
extend ActiveSupport::Concern
@@ -831,6 +840,8 @@ module ClassMethods
# objects are deleted *without* calling their +destroy+ method. If set to <tt>:nullify</tt> all associated
# objects' foreign keys are set to +NULL+ *without* calling their +save+ callbacks. *Warning:* This option is ignored when also using
# the <tt>:through</tt> option.
+ # the <tt>:through</tt> option. If set to <tt>:restrict</tt>
+ # this object cannot be deleted if it has any associated object.
# [:finder_sql]
# Specify a complete SQL statement to fetch the association. This is a good way to go for complex
# associations that depend on multiple tables. Note: When this option is used, +find_in_collection+ is _not_ added.
@@ -1469,9 +1480,15 @@ def add_touch_callbacks(reflection, touch_attribute)
# Creates before_destroy callback methods that nullify, delete or destroy
# has_many associated objects, according to the defined :dependent rule.
+ # If the association is marked as :dependent => :restrict, create a callback
+ # that prevents deleting entirely.
#
# See HasManyAssociation#delete_records. Dependent associations
# delete children, otherwise foreign key is set to NULL.
+ # See HasManyAssociation#delete_records. Dependent associations
+ # delete children if the option is set to :destroy or :delete_all, set the
+ # foreign key to NULL if the option is set to :nullify, and do not touch the
+ # child records if the option is set to :restrict.
#
# The +extra_conditions+ parameter, which is not used within the main
# Active Record codebase, is meant to allow plugins to define extra
@@ -1531,14 +1548,24 @@ def configure_dependency_for_has_many(reflection, extra_conditions = nil)
%@#{dependent_conditions}@)
end
CALLBACK
+ when :restrict
+ method_name = "has_many_dependent_restrict_for_#{reflection.name}".to_sym
+ define_method(method_name) do
+ unless send(reflection.name).empty?
+ raise DeleteRestrictionError.new(reflection)
+ end
+ end
+ before_destroy method_name
else
- raise ArgumentError, "The :dependent option expects either :destroy, :delete_all, or :nullify (#{reflection.options[:dependent].inspect})"
+ raise ArgumentError, "The :dependent option expects either :destroy, :delete_all, :nullify or :restrict (#{reflection.options[:dependent].inspect})"
end
end
end
# Creates before_destroy callback methods that nullify, delete or destroy
# has_one associated objects, according to the defined :dependent rule.
+ # If the association is marked as :dependent => :restrict, create a callback
+ # that prevents deleting entirely.
def configure_dependency_for_has_one(reflection)
if reflection.options.include?(:dependent)
name = reflection.options[:dependent]
@@ -1559,8 +1586,16 @@ def #{method_name}
association.update_attribute(#{reflection.primary_key_name.inspect}, nil) if association
end
eoruby
+ when :restrict
+ method_name = "has_one_dependent_restrict_for_#{reflection.name}".to_sym
+ define_method(method_name) do
+ unless send(reflection.name).nil?
+ raise DeleteRestrictionError.new(reflection)
+ end
+ end
+ before_destroy method_name
else
- raise ArgumentError, "The :dependent option expects either :destroy, :delete or :nullify (#{reflection.options[:dependent].inspect})"
+ raise ArgumentError, "The :dependent option expects either :destroy, :delete, :nullify or :restrict (#{reflection.options[:dependent].inspect})"
end
before_destroy method_name
@@ -439,9 +439,15 @@ def test_dependent_delete_and_destroy_with_belongs_to
assert_equal [author_address.id], AuthorAddress.destroyed_author_address_ids
end
- def test_invalid_belongs_to_dependent_option_raises_exception
+ def test_invalid_belongs_to_dependent_option_nullify_raises_exception
assert_raise ArgumentError do
Author.belongs_to :special_author_address, :dependent => :nullify
end
end
+
+ def test_invalid_belongs_to_dependent_option_restrict_raises_exception
+ assert_raise ArgumentError do
+ Author.belongs_to :special_author_address, :dependent => :restrict
+ end
+ end
end
@@ -836,6 +836,14 @@ def test_depends_and_nullify
assert_equal num_accounts, Account.count
end
+ def test_restrict
+ firm = RestrictedFirm.new(:name => 'restrict')
+ firm.save!
+ child_firm = firm.companies.create(:name => 'child')
+ assert !firm.companies.empty?
+ assert_raise(ActiveRecord::DeleteRestrictionError) { firm.destroy }
+ end
+
def test_included_in_collection
assert companies(:first_firm).clients.include?(Client.find(2))
end
@@ -177,7 +177,15 @@ def test_dependence_with_nil_associate
assert_nothing_raised { firm.destroy }
end
- def test_succesful_build_association
+ def test_dependence_with_restrict
+ firm = RestrictedFirm.new(:name => 'restrict')
+ firm.save!
+ account = firm.create_account(:credit_limit => 10)
+ assert !firm.account.nil?
+ assert_raise(ActiveRecord::DeleteRestrictionError) { firm.destroy }
+ end
+
+ def test_successful_build_association
firm = Firm.new("name" => "GlobalMegaCorp")
firm.save
@@ -95,6 +95,11 @@ class DependentFirm < Company
has_many :companies, :foreign_key => 'client_of', :dependent => :nullify
end
+class RestrictedFirm < Company
+ has_one :account, :foreign_key => "firm_id", :dependent => :restrict, :order => "id"
+ has_many :companies, :foreign_key => 'client_of', :order => "id", :dependent => :restrict
+end
+
class Client < Company
belongs_to :firm, :foreign_key => "client_of"
belongs_to :firm_with_basic_id, :class_name => "Firm", :foreign_key => "firm_id"

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