MakeMethods::Standard::Universal(3pm)			User Contributed Perl Documentation		     MakeMethods::Standard::Universal(3pm)

NAME

       Class::MakeMethods::Standard::Universal - Generic Methods

SYNOPSIS

	 package MyObject;
	 use Class::MakeMethods::Standard::Universal (
	   no_op => 'this',
	   abstract => 'that',
	   delegate => { name=>'play_music', target=>'instrument', method=>'play' },
	 );

DESCRIPTION

       The Standard::Universal suclass of MakeMethods provides a [INCOMPLETE].

   Calling Conventions
       When you "use" this package, the method names you provide as arguments cause subroutines to be generated and installed in your module.

       See "Calling Conventions" in Class::MakeMethods::Standard for more information.

   Declaration Syntax
       To declare methods, pass in pairs of a method-type name followed by one or more method names.

       Valid method-type names for this package are listed in "METHOD GENERATOR TYPES".

       See "Declaration Syntax" in Class::MakeMethods::Standard and "Parameter Syntax" in Class::MakeMethods::Standard for more information.

METHOD GENERATOR TYPES

   no_op - Placeholder
       For each method name passed, returns a subroutine with the following characteristics:

       o   Does nothing.

       You might want to create and use such methods to provide hooks for subclass activity.

       Sample declaration and usage:

	 package MyObject;
	 use Class::MakeMethods::Standard::Universal (
	   no_op => 'whatever',
	 );
	 ...

	 # Doesn't do anything
	 MyObject->whatever();

   abstract - Placeholder
       For each method name passed, returns a subroutine with the following characteristics:

       o   Fails with an error message.

       This is intended to support the use of abstract methods, that must be overidden in a useful subclass.

       If each subclass is expected to provide an implementation of a given method, using this abstract method will replace the generic error
       message below with the clearer, more explicit error message that follows it:

	 Can't locate object method "foo" via package "My::Subclass"
	 The "foo" method is abstract and can not be called on My::Subclass

       However, note that the existence of this method will be detected by UNIVERSAL::can(), so it is not suitable for use in optional interfaces,
       for which you may wish to be able to detect whether the method is supported or not.

       Sample declaration and usage:

	 package MyObject;
	 use Class::MakeMethods::Standard::Universal (
	   abstract => 'whatever',
	 );
	 ...

	 package MySubclass;
	 sub whatever { ... }

	 # Failure
	 MyObject->whatever();

	 # Success
	 MySubclass->whatever();

   call_methods - Call methods by name
       For each method name passed, returns a subroutine with the following characteristics:

       o   Accepts a hash of key-value pairs, or a reference to hash of such pairs. For each pair, the key is interpreted as the name of a method
	   to call, and the value is the argument to be passed to that method.

       Sample declaration and usage:

	 package MyObject;
	 use Class::MakeMethods::Standard::Universal (
	   call_methods => 'init',
	 );
	 ...

	 my $object = MyObject->new()
	 $object->init( foo => 'Foozle', bar => 'Barbados' );

	 # Equivalent to:
	 $object->foo('Foozle');
	 $object->bar('Barbados');

   join_methods - Concatenate results of other methods
       For each method name passed, returns a subroutine with the following characteristics:

       o   Has a list of other methods names as an arrayref in the 'methods' parameter. Required.

       o   When called, calls each of the named method on itself, in order, and returns the concatenation of their results.

       o   If a 'join' parameter is provided it is included between each method result.

       o   If the 'skip_blanks' parameter is omitted, or is provided with a true value, removes all undefined or empty-string values from the
	   results.

   alias - Call another method
       For each method name passed, returns a subroutine with the following characteristics:

       o   Calls another method on the same callee.

       You might create such a method to extend or adapt your class' interface.

       Sample declaration and usage:

	 package MyObject;
	 use Class::MakeMethods::Standard::Universal (
	   alias => { name=>'click_here', target=>'complex_machinery' }
	 );
	 sub complex_machinery { ... }
	 ...

	 $myobj->click_here(...); # calls $myobj->complex_machinery(...)

   delegate - Use another object to provide method
       For each method name passed, returns a subroutine with the following characteristics:

       o   Calls a method on self to retrieve another object, and then calls a method on that object and returns its value.

       You might want to create and use such methods to faciliate composition of objects from smaller objects.

       Sample declaration and usage:

	 package MyObject;
	 use Class::MakeMethods::Standard::Universal (
	   'Standard::Hash:object' => { name=>'instrument' },
	   delegate => { name=>'play_music', target=>'instrument', method=>'play' }
	 );
	 ...

	 my $object = MyObject->new();
	 $object->instrument( MyInstrument->new );
	 $object->play_music;

SEE ALSO

       See Class::MakeMethods for general information about this distribution.

       See Class::MakeMethods::Standard for more about this family of subclasses.

perl v5.10.1							    2004-09-06				     MakeMethods::Standard::Universal(3pm)