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!