NAME

DB::Pluggable - Add plugin support for the Perl debugger

SYNOPSIS

$ cat ~/.perldb

use DB::Pluggable;
use YAML;

$DB::PluginHandler = DB::Pluggable->new(config => Load <<EOYAML);
global:
  log:
    level: error

plugins:
  - module: BreakOnTestNumber
EOYAML

$DB::PluginHandler->run;

$ perl -d foo.pl

DESCRIPTION

This class adds plugin support to the Perl debugger. It is based on Hook::Modular, so see its documentation for details.

You need to have a ~/.perldb file (see perldebug for details) that invokes the plugin mechanism. The one in the synopsis will do, and there is a more commented one in this distribution's etc/perldb file.

Plugins should live in the DB::Pluggable:: namespace, like DB::Pluggable::BreakOnTestNumber does.

HOOKS

This class is very much in beta, so it's more like a proof of concept. Therefore, not all hooks imaginable have been added, only the ones to make this demo work. If you want more hooks or if the current hooks don't work for you, let me know.

The following hooks exist:

plugin.init

Called at the beginning of the run() method. The hook doesn't get any arguments.

db.watchfunction

Called from within DB::watchfunction(). If you want the debugger to call the function, you need to enable it by calling enable_watchfunction() somewhere within your plugin. It's a good idea to enable it as late as possible because it is being called very often. See the DB::Pluggable::BreakOnTestNumber source code for an example. The hook doesn't get any arguments.

db.cmd.b

Called when the b debugger command (used to set breakpoints) is invoked. See run() below for what the hook should return.

The hook passes these named arguments:

cmd

This is the first argument passed to DB::cmd_b().

line

This is the second argument passed to DB::cmd_b(). This is the most important argument as it contains the command line. See the DB::Pluggable::BreakOnTestNumber source code for an example.

dbline

This is the third argument passed to DB::cmd_b().

METHODS

enable_watchfunction

Tells the debugger to call DB::watchfunction(), which in turn calls the db.watchfunction hook on all plugins that have registered it.

run

First it calls the plugin.init hook, then it enables hooks for the relevant debugger commands (see above for which hooks are available).

Each command-related hook should return the appropriate constant from DB::Pluggable::Constants - either HANDLED if the hook has handled the command, or DECLINED if it didn't. If no hook has HANDLED the command, the default command subroutine (e.g., DB::cmd_b()) from perl5db.pl will be called.

BUGS AND LIMITATIONS

No bugs have been reported.

Please report any bugs or feature requests through the web interface at http://rt.cpan.org.

INSTALLATION

See perlmodinstall for information and options on installing Perl modules.

AVAILABILITY

The latest version of this module is available from the Comprehensive Perl Archive Network (CPAN). Visit <http://www.perl.com/CPAN/> to find a CPAN site near you. Or see http://search.cpan.org/dist/DB-Pluggable/.

The development version lives at http://github.com/hanekomu/db-pluggable/. Instead of sending patches, please fork this project using the standard git and github infrastructure.

AUTHORS

Marcel Grünauer, <marcel@cpan.org>

COPYRIGHT AND LICENSE

Copyright 2008-2009 by Marcel Grünauer.

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.