Manual Reference Pages - CLASS::HANDLE (3)
Class::Handle - Create objects that are handles to Classes
# Create a class handle
my $class = Class::Handle->new( Foo::Class );
my $name = $class->name;
# UNIVERSAL type methods
$class->isa( Foo:Bar );
$class->can( blah );
# Class::Inspector type methods
$class->function_exists( function );
$class->methods( public, full );
# Class::ISA type methods
# Loading and unloading
Class related functionality in Perl is broken up into a variety of different
modules. Class::Handle attempts to provide a convenient object wrapper around
the various different types of functions that can be performed on a class.
Please note that this is an initial non-production quality release, and should
be used as such. Functionality and API are subject to change without notice.
Currently, Class::Handle provies what is effectively a combined API from
UNIVERSAL, Class::ISA and Class::Inspector for obtaining information
about a Class, and some additional task methods, such as load to common
tasks relating to classes.
To ensure we maintain compliance with other classes that rely on
methods provided by UNIVERSAL, Class::Handle acts in the normal way when
something like <Class::Handle-VERSION>> is called. That is, it returns the
version of Class::Handle itself. When UNIVERSAL methods are called on
an instantiation the method is changed to act on the class we have a handle
to. For example, the two following statements are equivalent.
# Getting the version directly
# Getting the version via Class::Handle
my $class = Class::Handle->new( Foo::Bar );
This also applies to the isa and can methods.
The new constructor will create a new handle to a class or unknown
existance or status. That is, it wont check that the class actually exists
at this time. It WILL however check to make sure that your class name is legal.
Returns a new Class::Handle object on success
Returns undef if the class name is illegal
The c<name> method returns the name of the class as original specified in
Find the version for the class. Does not check that the class is loaded ( at
this time ).
Returns the version on success, undef if the class does not defined a
$VERSION or the class is not loaded.
Checks to see if the class is a subclass of another class. Does not check that
the class is loaded ( at this time ).
Returns true/false as for UNIVERSAL::isa
Checks to see if a particular method is defined for the class.
Returns a CODE ref to the function is the method is available,
or false if the class does not have that method available.
Checks to see if a particular class is installed on the machine, or at least
that the class is available to perl. In this case, class really means
module. This methods cannot detect a class that is not a module. ( Has its
own file ).
Returns true if the class is installed and available, or false otherwise.
Checks to see if a class is loaded. In this case, class does NOT mean
module. The loaded method will return true for classes that do not have
their own file.
For example, if a module Foo contains the classes Foo, Foo::Bar and
Foo::Buffy, the loaded method will return true for all of the classes.
Returns true if the class is loaded, or false otherwise.
Returns the base filename for a class. For example, for the class
Foo::Bar, loaded would return "Foo/Bar.pm".
The filename method is platform neutral, it should always return the
filename in the correct format for your platform.
The resolved_filename will attempt to find the real file on your system
that will be used when a class is loaded. If additional paths are provided
as argument, they will be tried first, before the contents of the @INC array.
If a file cannot be found to match the class, returns false.
If the class is loaded, returns the name of the file that it was originally
Returns false if the class is not loaded, or did not have its own file.
Returns a list of the names of all the functions in the classes immediate
namespace. Note that this is not the METHODS of the class, just the functions.
Returns a reference to an array of the function names on success.
Returns undef on error or if the class is not loaded.
Returns a list of references to all the functions in the classes immediate
Returns a reference to an array of CODE refs of the functions on
success, or undef on error or if the class is not loaded.
Checks to see if the function exists in the class. Note that this is as a
function, not as a method. To see if a method exists for a class, use the
can method in UNIVERSAL, and hence to every other class.
Returns true if the function exists, false if the function does not exist,
or undef on error, or if the class is not loaded.
Attempts to find the methods available to the class. This includes everything
in the classes super path up to, but NOT including, UNIVERSAL. Returns a
reference to an array of the names of all the available methods on success.
Returns undef if the class is not loaded.
Any provided options are passed through, and alter the response in the same
way as for the options to <Class::Inspector-methods()>>, that is, public,
private, full and expanded, and combinations thereof.
The subclasses method will search then entire namespace (and thus
<B>allB> currently loaded classes) to find all of the subclasses of the
The actual test will be done by calling isa on the class as a static
method. (i.e. <My::Class-isa($class)>>.
Returns a reference to a list of the names of the loaded classes that match
the class provided, or false is none match, or undef if the class name
provided is invalid.
The super_path method is a straight pass through to the
Class::ISA::super_path function. Returns an ordered list of
class names, with no duplicates. The list does NOT include the class itself,
or the UNIVERSAL class.
As above, but includes ourself at the beginning of the path. Directly
passes through to Class::ISA.
The full_super_path method is an additional method not in Class::ISA.
It returns as for super_path, except that it also contains BOTH the
class itself, and UNIVERSAL. This full list is more technically accurate,
but less commonly used, and as such isnt available from Class::ISA
No known bugs. Additional feature requests are being taken.
Bugs should be reported via the CPAN bug tracking system
For other inquiries, contact the author
Adam Kennedy <email@example.com>, <http://ali.as/>
UNIVERSAL, Class::ISA, and Class::Inspector, which provide
most of the functionality for this class.
Copyright (c) 2002 - 2006 Adam Kennedy.
This program is free software; you can redistribute
it and/or modify it under the same terms as Perl itself.
The full text of the license can be found in the
LICENSE file included with this module.
|perl v5.20.3 ||CLASS::HANDLE (3) ||2007-12-11 |
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