/ 
Class-MakeMethods-1.01
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/ Class::MakeMethods::Standard::Universal

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:

  • 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:

  • 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:

  • 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:

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

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

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

  • 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:

  • 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:

  • 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.