Usage of The SingleForwardable is like Fowadable module.
Defines a method method which delegates to obj (i.e. it calls the method of the same name in obj). If new_name is provided, it is used as the name for the delegate method.
# File forwardable.rb, line 248
def def_single_delegator(accessor, method, ali = method)
line_no = __LINE__; str = %{
def #{ali}(*args, &block)
begin
#{accessor}.__send__(:#{method}, *args, &block)
rescue Exception
$@.delete_if{|s| %r"#{Regexp.quote(__FILE__)}"o =~ s} unless Forwardable::debug
::Kernel::raise
end
end
}
instance_eval(str, __FILE__, __LINE__)
end
Shortcut for defining multiple delegator methods, but with no provision for using a different name. The following two code samples have the same effect:
def_delegators :@records, :size, :<<, :map def_delegator :@records, :size def_delegator :@records, :<< def_delegator :@records, :map
# File forwardable.rb, line 235
def def_single_delegators(accessor, *methods)
methods.delete("__send__")
methods.delete("__id__")
for method in methods
def_single_delegator(accessor, method)
end
end
Takes a hash as its argument. The key is a symbol or an array of symbols. These symbols correspond to method names. The value is the accessor to which the methods will be delegated.
# File forwardable.rb, line 215
def single_delegate(hash)
hash.each{ |methods, accessor|
methods = [methods] unless methods.respond_to?(:each)
methods.each{ |method|
def_single_delegator(accessor, method)
}
}
end