2007-12-21 08:48:59 +01:00
|
|
|
class Object
|
|
|
|
# Available in 1.8.6 and later.
|
|
|
|
unless respond_to?(:instance_variable_defined?)
|
|
|
|
def instance_variable_defined?(variable)
|
|
|
|
instance_variables.include?(variable.to_s)
|
|
|
|
end
|
|
|
|
end
|
|
|
|
|
2008-05-18 06:22:34 +02:00
|
|
|
# Returns a hash that maps instance variable names without "@" to their
|
|
|
|
# corresponding values. Keys are strings both in Ruby 1.8 and 1.9.
|
|
|
|
#
|
|
|
|
# class C
|
|
|
|
# def initialize(x, y)
|
|
|
|
# @x, @y = x, y
|
|
|
|
# end
|
|
|
|
# end
|
|
|
|
#
|
|
|
|
# C.new(0, 1).instance_values # => {"x" => 0, "y" => 1}
|
2007-12-21 08:48:59 +01:00
|
|
|
def instance_values #:nodoc:
|
|
|
|
instance_variables.inject({}) do |values, name|
|
|
|
|
values[name.to_s[1..-1]] = instance_variable_get(name)
|
|
|
|
values
|
|
|
|
end
|
|
|
|
end
|
|
|
|
|
2008-05-18 06:22:34 +02:00
|
|
|
# Returns an array of instance variable names including "@". They are strings
|
|
|
|
# both in Ruby 1.8 and 1.9.
|
|
|
|
#
|
|
|
|
# class C
|
|
|
|
# def initialize(x, y)
|
|
|
|
# @x, @y = x, y
|
|
|
|
# end
|
|
|
|
# end
|
|
|
|
#
|
|
|
|
# C.new(0, 1).instance_variable_names # => ["@y", "@x"]
|
|
|
|
if RUBY_VERSION >= '1.9'
|
|
|
|
def instance_variable_names
|
|
|
|
instance_variables.map(&:to_s)
|
|
|
|
end
|
|
|
|
else
|
|
|
|
alias_method :instance_variable_names, :instance_variables
|
|
|
|
end
|
|
|
|
|
|
|
|
# Copies the instance variables of +object+ into +self+.
|
|
|
|
#
|
|
|
|
# Instance variable names in the +exclude+ array are ignored. If +object+
|
|
|
|
# responds to <tt>protected_instance_variables</tt> the ones returned are
|
|
|
|
# also ignored. For example, Rails controllers implement that method.
|
|
|
|
#
|
|
|
|
# In both cases strings and symbols are understood, and they have to include
|
|
|
|
# the at sign.
|
|
|
|
#
|
|
|
|
# class C
|
|
|
|
# def initialize(x, y, z)
|
|
|
|
# @x, @y, @z = x, y, z
|
|
|
|
# end
|
|
|
|
#
|
|
|
|
# def protected_instance_variables
|
|
|
|
# %w(@z)
|
|
|
|
# end
|
|
|
|
# end
|
|
|
|
#
|
|
|
|
# a = C.new(0, 1, 2)
|
|
|
|
# b = C.new(3, 4, 5)
|
|
|
|
#
|
|
|
|
# a.copy_instance_variables_from(b, [:@y])
|
|
|
|
# # a is now: @x = 3, @y = 1, @z = 2
|
2007-12-21 08:48:59 +01:00
|
|
|
def copy_instance_variables_from(object, exclude = []) #:nodoc:
|
|
|
|
exclude += object.protected_instance_variables if object.respond_to? :protected_instance_variables
|
|
|
|
|
|
|
|
vars = object.instance_variables.map(&:to_s) - exclude.map(&:to_s)
|
|
|
|
vars.each { |name| instance_variable_set(name, object.instance_variable_get(name)) }
|
|
|
|
end
|
|
|
|
end
|