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
# 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 won't 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-"
>>, that is, 'public', 'private', 'full' and 'expanded',
and combinations thereof.
The "subclasses" method will search then entire namespace (and thus
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
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 isn't
available from Class::ISA itself.
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 <firstname.lastname@example.org>, <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