NAME¶
Monkey::Patch - Scoped monkeypatching (you can at least play nice)
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 receives 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!