Class::MakeMethods::Standard::Universal(3pm)

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.

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 overridden 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 facilitate 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;