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Fix a bug where class extentions were conflicting with ActiveSupport

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Matthew Ford 2009-03-05 15:47:53 +00:00 committed by Matt Aimonetti
parent d95b9de50d
commit fdb0854859
2 changed files with 215 additions and 140 deletions
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296
lib/couchrest/support/class.rb
View file

@ -25,151 +25,167 @@
# example, an array without those additions being shared with either their
# parent, siblings, or children, which is unlike the regular class-level
# attributes that are shared across the entire hierarchy.
class Class
# Defines class-level and instance-level attribute reader.
#
# @param *syms<Array> Array of attributes to define reader for.
# @return <Array[#to_s]> List of attributes that were made into cattr_readers
#
# @api public
#
# @todo Is this inconsistent in that it does not allow you to prevent
# an instance_reader via :instance_reader => false
def cattr_reader(*syms)
syms.flatten.each do |sym|
next if sym.is_a?(Hash)
class_eval(<<-RUBY, __FILE__, __LINE__ + 1)
unless defined? @@#{sym}
@@#{sym} = nil
end
def self.#{sym}
@@#{sym}
end
def #{sym}
@@#{sym}
end
RUBY
module CouchRest
module ClassExtension
def self.included(base)
if CouchRest::ClassExtension::InstanceMethods.instance_methods.all? {|m| base.respond_to?(m)}
# do nothing
elsif CouchRest::ClassExtension::InstanceMethods.instance_methods.any? {|m| base.respond_to?(m)}
raise RuntimeError, "Conflicting extentions to Class, work it out"
else
base.send(:include, CouchRest::ClassExtension::InstanceMethods)
end
end
module InstanceMethods
# Defines class-level and instance-level attribute reader.
#
# @param *syms<Array> Array of attributes to define reader for.
# @return <Array[#to_s]> List of attributes that were made into cattr_readers
#
# @api public
#
# @todo Is this inconsistent in that it does not allow you to prevent
# an instance_reader via :instance_reader => false
def cattr_reader(*syms)
syms.flatten.each do |sym|
next if sym.is_a?(Hash)
class_eval(<<-RUBY, __FILE__, __LINE__ + 1)
unless defined? @@#{sym}
@@#{sym} = nil
end
end
# Defines class-level (and optionally instance-level) attribute writer.
#
# @param <Array[*#to_s, Hash{:instance_writer => Boolean}]> Array of attributes to define writer for.
# @option syms :instance_writer<Boolean> if true, instance-level attribute writer is defined.
# @return <Array[#to_s]> List of attributes that were made into cattr_writers
#
# @api public
def cattr_writer(*syms)
options = syms.last.is_a?(Hash) ? syms.pop : {}
syms.flatten.each do |sym|
class_eval(<<-RUBY, __FILE__, __LINE__ + 1)
unless defined? @@#{sym}
@@#{sym} = nil
end
def self.#{sym}
@@#{sym}
end
def self.#{sym}=(obj)
@@#{sym} = obj
end
RUBY
def #{sym}
@@#{sym}
end
RUBY
end
end
unless options[:instance_writer] == false
class_eval(<<-RUBY, __FILE__, __LINE__ + 1)
def #{sym}=(obj)
@@#{sym} = obj
end
RUBY
# Defines class-level (and optionally instance-level) attribute writer.
#
# @param <Array[*#to_s, Hash{:instance_writer => Boolean}]> Array of attributes to define writer for.
# @option syms :instance_writer<Boolean> if true, instance-level attribute writer is defined.
# @return <Array[#to_s]> List of attributes that were made into cattr_writers
#
# @api public
def cattr_writer(*syms)
options = syms.last.is_a?(Hash) ? syms.pop : {}
syms.flatten.each do |sym|
class_eval(<<-RUBY, __FILE__, __LINE__ + 1)
unless defined? @@#{sym}
@@#{sym} = nil
end
def self.#{sym}=(obj)
@@#{sym} = obj
end
RUBY
unless options[:instance_writer] == false
class_eval(<<-RUBY, __FILE__, __LINE__ + 1)
def #{sym}=(obj)
@@#{sym} = obj
end
RUBY
end
end
end
# Defines class-level (and optionally instance-level) attribute accessor.
#
# @param *syms<Array[*#to_s, Hash{:instance_writer => Boolean}]> Array of attributes to define accessor for.
# @option syms :instance_writer<Boolean> if true, instance-level attribute writer is defined.
# @return <Array[#to_s]> List of attributes that were made into accessors
#
# @api public
def cattr_accessor(*syms)
cattr_reader(*syms)
cattr_writer(*syms)
end
# Defines class-level inheritable attribute reader. Attributes are available to subclasses,
# each subclass has a copy of parent's attribute.
#
# @param *syms<Array[#to_s]> Array of attributes to define inheritable reader for.
# @return <Array[#to_s]> Array of attributes converted into inheritable_readers.
#
# @api public
#
# @todo Do we want to block instance_reader via :instance_reader => false
# @todo It would be preferable that we do something with a Hash passed in
# (error out or do the same as other methods above) instead of silently
# moving on). In particular, this makes the return value of this function
# less useful.
def class_inheritable_reader(*ivars)
instance_reader = ivars.pop[:reader] if ivars.last.is_a?(Hash)
ivars.each do |ivar|
self.class_eval <<-RUBY, __FILE__, __LINE__ + 1
def self.#{ivar}
return @#{ivar} if self.object_id == #{self.object_id} || defined?(@#{ivar})
ivar = superclass.#{ivar}
return nil if ivar.nil? && !#{self}.instance_variable_defined?("@#{ivar}")
@#{ivar} = ivar && !ivar.is_a?(Module) && !ivar.is_a?(Numeric) && !ivar.is_a?(TrueClass) && !ivar.is_a?(FalseClass) && !ivar.is_a?(Symbol) ? ivar.dup : ivar
end
RUBY
unless instance_reader == false
self.class_eval <<-RUBY, __FILE__, __LINE__ + 1
def #{ivar}
self.class.#{ivar}
end
RUBY
end
end
end
# Defines class-level inheritable attribute writer. Attributes are available to subclasses,
# each subclass has a copy of parent's attribute.
#
# @param *syms<Array[*#to_s, Hash{:instance_writer => Boolean}]> Array of attributes to
# define inheritable writer for.
# @option syms :instance_writer<Boolean> if true, instance-level inheritable attribute writer is defined.
# @return <Array[#to_s]> An Array of the attributes that were made into inheritable writers.
#
# @api public
#
# @todo We need a style for class_eval <<-HEREDOC. I'd like to make it
# class_eval(<<-RUBY, __FILE__, __LINE__), but we should codify it somewhere.
def class_inheritable_writer(*ivars)
instance_writer = ivars.pop[:instance_writer] if ivars.last.is_a?(Hash)
ivars.each do |ivar|
self.class_eval <<-RUBY, __FILE__, __LINE__ + 1
def self.#{ivar}=(obj)
@#{ivar} = obj
end
RUBY
unless instance_writer == false
self.class_eval <<-RUBY, __FILE__, __LINE__ + 1
def #{ivar}=(obj) self.class.#{ivar} = obj end
RUBY
end
end
end
# Defines class-level inheritable attribute accessor. Attributes are available to subclasses,
# each subclass has a copy of parent's attribute.
#
# @param *syms<Array[*#to_s, Hash{:instance_writer => Boolean}]> Array of attributes to
# define inheritable accessor for.
# @option syms :instance_writer<Boolean> if true, instance-level inheritable attribute writer is defined.
# @return <Array[#to_s]> An Array of attributes turned into inheritable accessors.
#
# @api public
def class_inheritable_accessor(*syms)
class_inheritable_reader(*syms)
class_inheritable_writer(*syms)
end
end
end
# Defines class-level (and optionally instance-level) attribute accessor.
#
# @param *syms<Array[*#to_s, Hash{:instance_writer => Boolean}]> Array of attributes to define accessor for.
# @option syms :instance_writer<Boolean> if true, instance-level attribute writer is defined.
# @return <Array[#to_s]> List of attributes that were made into accessors
#
# @api public
def cattr_accessor(*syms)
cattr_reader(*syms)
cattr_writer(*syms)
end
# Defines class-level inheritable attribute reader. Attributes are available to subclasses,
# each subclass has a copy of parent's attribute.
#
# @param *syms<Array[#to_s]> Array of attributes to define inheritable reader for.
# @return <Array[#to_s]> Array of attributes converted into inheritable_readers.
#
# @api public
#
# @todo Do we want to block instance_reader via :instance_reader => false
# @todo It would be preferable that we do something with a Hash passed in
# (error out or do the same as other methods above) instead of silently
# moving on). In particular, this makes the return value of this function
# less useful.
def class_inheritable_reader(*ivars)
instance_reader = ivars.pop[:reader] if ivars.last.is_a?(Hash)
ivars.each do |ivar|
self.class_eval <<-RUBY, __FILE__, __LINE__ + 1
def self.#{ivar}
return @#{ivar} if self.object_id == #{self.object_id} || defined?(@#{ivar})
ivar = superclass.#{ivar}
return nil if ivar.nil? && !#{self}.instance_variable_defined?("@#{ivar}")
@#{ivar} = ivar && !ivar.is_a?(Module) && !ivar.is_a?(Numeric) && !ivar.is_a?(TrueClass) && !ivar.is_a?(FalseClass) && !ivar.is_a?(Symbol) ? ivar.dup : ivar
end
RUBY
unless instance_reader == false
self.class_eval <<-RUBY, __FILE__, __LINE__ + 1
def #{ivar}
self.class.#{ivar}
end
RUBY
end
end
end
# Defines class-level inheritable attribute writer. Attributes are available to subclasses,
# each subclass has a copy of parent's attribute.
#
# @param *syms<Array[*#to_s, Hash{:instance_writer => Boolean}]> Array of attributes to
# define inheritable writer for.
# @option syms :instance_writer<Boolean> if true, instance-level inheritable attribute writer is defined.
# @return <Array[#to_s]> An Array of the attributes that were made into inheritable writers.
#
# @api public
#
# @todo We need a style for class_eval <<-HEREDOC. I'd like to make it
# class_eval(<<-RUBY, __FILE__, __LINE__), but we should codify it somewhere.
def class_inheritable_writer(*ivars)
instance_writer = ivars.pop[:instance_writer] if ivars.last.is_a?(Hash)
ivars.each do |ivar|
self.class_eval <<-RUBY, __FILE__, __LINE__ + 1
def self.#{ivar}=(obj)
@#{ivar} = obj
end
RUBY
unless instance_writer == false
self.class_eval <<-RUBY, __FILE__, __LINE__ + 1
def #{ivar}=(obj) self.class.#{ivar} = obj end
RUBY
end
end
end
# Defines class-level inheritable attribute accessor. Attributes are available to subclasses,
# each subclass has a copy of parent's attribute.
#
# @param *syms<Array[*#to_s, Hash{:instance_writer => Boolean}]> Array of attributes to
# define inheritable accessor for.
# @option syms :instance_writer<Boolean> if true, instance-level inheritable attribute writer is defined.
# @return <Array[#to_s]> An Array of attributes turned into inheritable accessors.
#
# @api public
def class_inheritable_accessor(*syms)
class_inheritable_reader(*syms)
class_inheritable_writer(*syms)
end
end
Class.send(:include, CouchRest::ClassExtension)

59
spec/couchrest/support/class_spec.rb Normal file
View file

@ -0,0 +1,59 @@
require File.join(File.dirname(__FILE__), '..', '..', 'spec_helper')
require File.join(File.dirname(__FILE__), '..', '..', '..', 'lib', 'couchrest', 'support', 'class')
describe CouchRest::ClassExtension do
before :all do
class FullyDefinedClassExtensions
def self.respond_to?(method)
if CouchRest::ClassExtension::InstanceMethods.instance_methods.include?(method)
true
else
super
end
end
end
class PartDefinedClassExtensions
def self.respond_to?(method)
methods = CouchRest::ClassExtension::InstanceMethods.instance_methods
methods.delete('cattr_reader')
if methods.include?(method)
false
else
super
end
end
end
class NoClassExtensions
def self.respond_to?(method)
if CouchRest::ClassExtension::InstanceMethods.instance_methods.include?(method)
false
else
super
end
end
end
end
it "should not include InstanceMethods if the class extensions are already defined" do
FullyDefinedClassExtensions.send(:include, CouchRest::ClassExtension)
FullyDefinedClassExtensions.ancestors.should_not include(CouchRest::ClassExtension::InstanceMethods)
end
it "should raise RuntimeError if the class extensions are only partially defined" do
lambda {
PartDefinedClassExtensions.send(:include, CouchRest::ClassExtension)
}.should raise_error(RuntimeError)
end
it "should include class extensions if they are not already defined" do
NoClassExtensions.send(:include, CouchRest::ClassExtension)
NoClassExtensions.ancestors.should include(CouchRest::ClassExtension::InstanceMethods)
end
end