Monkey::Patch(3pm)

Usage

    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

Version

version 0.03

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).

Releases

7 releases since Debian 7 (Wheezy); the text changed 3 times.