Sven/PHP

Debugging PHP

In MediaWiki there is a profiler that can be set, see MW:How to debug.

Debuggers generally use a W:Stack trace. This can be approximated by using print and die statements in sections of code. The combination of print_r and func_get_args allows you to return an array of args that a function was called with;

<php> print_r(func_get_args()); </php>

Casting an object of an array builds an array of the properties, mapping property names to values. e.g.

{{{1}}}

outputs;

Array

(

[name] => Fred

[age] => 35

)

Introspection

Pages 147-153 (Programming php) for introspection functions for Objects in php. http://www.php.net/manual/en/ref.classobj.php

• class_exists

{{{1}}}

From Sven/Notes, Extension:Fasta.php;

{{{1}}}

PHP errors

To see PHP errors, add this to the very top of LocalSettings.php:

<php> error_reporting(E_ALL); ini_set("display_errors", 1); </php>

MediaWiki profiler

The article how to debug MediaWiki provides information on setting up the profiler by adding the globals to your LocalSettings.php file;

{{{1}}}

However if you include in an extension;

<php> include("$IP/includes/GlobalFunctions.php"); wfDebug("This is just testing the debug tracing stuff\n"); </php>

there seems to be no output in the generated log file.

See also

Debugging

• MediaWiki code snippets
• W:Debugging
• MW:How to become a MediaWiki hacker
• MW:Extensions_FAQ

http://www.php.net

• Classes and Objects (PHP 5)
• Introspection:Class/Object Functions
• Scope Resolution Operator (::)

Documentation

• Deoxygen MediaWiki Documentation
• MW:Manual:Coding_conventions
• MW:Manual:Extensions
• MW:Manual:$wgExtensionFunctions

Extensions

• Extension:PayPal.php - currently contains debugging

Resources

• OOP documentation
• http://en.wikibooks.org/wiki/Programming:PHP