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;

print_r(func_get_args());

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

class Person {
 var $name = "Fred";
 var $age  = 35;
}
$o = new Person;
$a = (array) $o
print_r($a);

outputs;

Array

(

[name] => Fred

[age] => 35

)

See pages 147-153 (Programming php) for introspection functions for Objects in php.

• class_exists
• get_declared_classes
• get_class_methods
• get_class_vars
• get_parent_class

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>

See also

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