monkey::patch(3pm) [debian man page]

Monkey::Patch(3pm)					User Contributed Perl Documentation					Monkey::Patch(3pm)

NAME

       Monkey::Patch - Scoped monkeypatching (you can at least play nice)

VERSION

       version 0.03

SYNOPSIS

	   use Monkey::Patch qw(:all);

	   sub some_subroutine {
	       my $pkg = patch_class 'Some::Class' => 'something' => sub {
		   my $original = shift;
		   say "Whee!";
		   $original->(@_);
	       };
	       Some::Class->something(); # says Whee! and does whatever
	       undef $pkg;
	       Some::Class->something(); # no longer says Whee!

	       my $obj = Some::Class->new;
	       my $obj2 = Some::Class->new;

	       my $whoah = patch_object $obj, 'twiddle' => sub {
		   my $original = shift;
		   my $self	= shift;
		   say "Whoah!";
		   $self->$original(@_);
	       };

	       $obj->twiddle();  # says Whoah!
	       $obj2->twiddle(); # doesn't
	       $obj->twiddle()	 # still does
	       undef $whoah;
	       $obj->twiddle();  # but not any more

SUBROUTINES

       The following subroutines are available (either individually or via :all)

   patch_package (package, subname, code)
       Wraps "package"'s subroutine named <subname> with your <code>.  Your code recieves the original subroutine as its first argument, followed
       by any arguments the subroutine would have normally gotten.  You can always call the subroutine ref your received; if there was no
       subroutine by that name, the coderef will simply do nothing.

   patch_class (class, methodname, code)
       Just like "patch_package", except that the @ISA chain is walked when you try to call the original subroutine if there wasn't any subroutine
       by that name in the package.

   patch_object (object, methodname, code)
       Just like "patch_class", except that your code will only get called on the object you pass, not the entire class.

HANDLES

       All the "patch" functions return a handle object.  As soon as you lose the value of the handle (by calling in void context, assigning over
       the variable, undeffing the variable, letting it go out of scope, etc), the monkey patch is unwrapped.  You can stack monkeypatches and let
       go of the handles in any order; they obey a stack discipline, and the most recent valid monkeypatch will always be called.  Calling the
       "original" argument to your wrapper routine will always call the next-most-recent monkeypatched version (or, the original subroutine, of
       course).

BUGS

       This magic is only faintly black, but mucking around with the symbol table is not for the faint of heart.  Help make this module better by
       reporting any strange behavior that you see!

perl v5.10.1							    2010-07-16							Monkey::Patch(3pm)

UNIVERSAL(3pm)						 Perl Programmers Reference Guide					    UNIVERSAL(3pm)

NAME

       UNIVERSAL - base class for ALL classes (blessed references)

SYNOPSIS

	   $is_io = $fd->isa("IO::Handle");
	   $is_io = Class->isa("IO::Handle");

	   $sub = $obj->can("print");
	   $sub = Class->can("print");

	   use UNIVERSAL qw( isa can VERSION );
	   $yes = isa $ref, "HASH" ;
	   $sub = can $ref, "fandango" ;
	   $ver = VERSION $obj ;

DESCRIPTION

       "UNIVERSAL" is the base class which all bless references will inherit from, see perlobj.

       "UNIVERSAL" provides the following methods and functions:

       $obj->isa( TYPE ), CLASS->isa( TYPE ), isa( VAL, TYPE )
	       C<TYPE> is a package name
	       $obj is a blessed reference or a string containing a package name
	       C<CLASS> is a package name
	       C<VAL> is any of the above or an unblessed reference

	   When used as an instance or class method ("$obj-"isa( TYPE )>), "isa" returns true if $obj is blessed into package "TYPE" or inherits
	   from package "TYPE".

	   When used as a class method ("CLASS-"isa( TYPE )>; sometimes referred to as a static method), "isa" returns true if "CLASS" inherits
	   from (or is itself) the name of the package "TYPE" or inherits from package "TYPE".

	   When used as a function, like

	      use UNIVERSAL qw( isa ) ;
	      $yes = isa $h, "HASH";
	      $yes = isa "Foo", "Bar";

	   or

	      require UNIVERSAL ;
	      $yes = UNIVERSAL::isa $a, "ARRAY";

	   , "isa" returns true in the same cases as above and also if "VAL" is an unblessed reference to a perl variable of type "TYPE", such as
	   "HASH", "ARRAY", or "Regexp".

       $obj->can( METHOD ), CLASS->can( METHOD ), can( VAL, METHOD )
	   "can" checks if the object or class has a method called "METHOD". If it does then a reference to the sub is returned. If it does not
	   then undef is returned.  This includes methods inherited or imported by $obj, "CLASS", or "VAL".

	   "can" cannot know whether an object will be able to provide a method through AUTOLOAD, so a return value of undef does not necessarily
	   mean the object will not be able to handle the method call. To get around this some module authors use a forward declaration (see perl-
	   sub) for methods they will handle via AUTOLOAD. For such 'dummy' subs, "can" will still return a code reference, which, when called,
	   will fall through to the AUTOLOAD. If no suitable AUTOLOAD is provided, calling the coderef will cause an error.

	   "can" can be called as a class (static) method, an object method, or a function.

	   When used as a function, if "VAL" is a blessed reference or package name which has a method called "METHOD", "can" returns a reference
	   to the subroutine.  If "VAL" is not a blessed reference, or if it does not have a method "METHOD", undef is returned.

       VERSION ( [ REQUIRE ] )
	   "VERSION" will return the value of the variable $VERSION in the package the object is blessed into. If "REQUIRE" is given then it will
	   do a comparison and die if the package version is not greater than or equal to "REQUIRE".

	   "VERSION" can be called as either a class (static) method, an object method or or a function.

       These subroutines should not be imported via "use UNIVERSAL qw(...)".  If you want simple local access to them you can do

	 *isa = &UNIVERSAL::isa;

       to import isa into your package.

perl v5.8.0							    2002-06-01							    UNIVERSAL(3pm)