src::mod_perl::docs::api::Apache2::porting(3)

NAME
Apache2::porting -- a helper module for mod_perl 1.0 to mod_perl 2.0 porting

Synopsis
  # either add at the very beginning of startup.pl
  use Apache2::porting;

  # or httpd.conf
  PerlModule Apache2::porting

  # now issue requests and look at the error_log file for hints

Description
"Apache2::porting" helps to port mod_perl 1.0 code to run under mod_perl 2.0. It doesn't provide any back-compatibility functionality, however it knows to trap methods calls that are no longer in the mod_perl 2.0 API and tell what should be used instead if at all. If you attempts to use mod_perl 2.0 methods without first loading the modules that contain them, it will tell you which modules you need to load. Finally if your code tries to load modules that no longer exist in mod_perl 2.0 it'll also tell you what are the modules that should be used instead.

"Apache2::porting" communicates with users via the error_log file. Everytime it traps a problem, it logs the solution (if it finds one) to the error log file. If you use this module coupled with "Apache2::Reload" you will be able to port your applications quickly without needing to restart the server on every modification.

It starts to work only when child process start and doesn't work for the code that gets loaded at the server startup. This limitation is explained in the Culprits section.

It relies heavily on "ModPerl::MethodLookup". which can also be used manually to lookup things.

Culprits
"Apache2::porting" uses the "UNIVERSAL::AUTOLOAD" function to provide its functionality. However it seems to be impossible to create "UNIVERSAL::AUTOLOAD" at the server startup, Apache segfaults on restart. Therefore it performs the setting of "UNIVERSAL::AUTOLOAD" only during the child_init phase, when child processes start. As a result it can't help you with things that get preloaded at the server startup.

If you know how to resolve this problem, please let us know. To reproduce the problem try to use an earlier phase, e.g. "PerlPostConfigHandler":

  Apache2::ServerUtil->server->push_handlers(PerlPostConfigHandler => \&porting_autoload);

META: Though there is a better solution at work, which assigns AUTOLOAD for each class separately, instead of using UNIVERSAL. See the discussion on the dev list (hint: search the archive for EazyLife)

See Also
mod_perl 2.0 documentation.

Copyright
mod_perl 2.0 and its core modules are copyrighted under The Apache Software License, Version 2.0.

Authors
The mod_perl development team and numerous contributors.