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

)

Introspection

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

• class_exists

<php>

1. Example:

$classes = get_declared_classes(); foreach($classes as $list) {

 print ("$list 
");

} </php>

• get_declared_classes
• get_class_methods
• get_class_vars
• get_parent_class

<php> function printArray(&$array) {

 if (isset($wgCommandLineMode)) {
   $rc = "\n";
 } else {
   $rc ="
";
 }

 foreach($array as $key => $value) {
   print "array: key => $value$rc";
 }
 return();

}

</php>

From Sven/Notes, Extension:Fasta.php; <php>

1. Logging to an article from within the MW environment

function logAdd($article,$msg) { $ts = $GLOBALS['wgLang']->timeanddate(wfTimestampNow(),true); $la = new Article(Title::newFromText($article)); $la->quickEdit($la->getContent()."\n*$ts: $msg"); }

1. Logging to a file

function logFile($file, $msg) { $fh = fopen($file,'a'); $ts = $GLOBALS['wgLang']->timeanddate(wfTimestampNow(),true); if(is_array($msg)) $msg = print_r($msg, true); fwrite($fh, "\n$ts: $msg"); # $ts = date("Y-m-d H:i:s"); # @file_put_contents($wgPayPalLog,"$ts $text\n",FILE_APPEND); } </php>

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;

<php> /**

* The debug log file should be not be publicly accessible if it is used, as it
* may contain private data.  But it must be in a directory to which PHP run
* within your Web server can write. */

$wgDebugLogFile = '/tmp/MW_log.txt';

2. Profiling / debugging

/** Enable for more detailed by-function times in debug log */ $wgProfiling = true; /** Only record profiling info for pages that took longer than this */ $wgProfileLimit = 0.0; /** Don't put non-profiling info into log file */ $wgProfileOnly = false; /** Log sums from profiling into "profiling" table in db. */ $wgProfileToDatabase = false; /** Only profile every n requests when profiling is turned on */ $wgProfileSampleRate = 1; /** If true, print a raw call tree instead of per-function report */ $wgProfileCallTree = false; /** If not empty, specifies profiler type to load */ $wgProfilerType = ;

/** Settings for UDP profiler */ $wgUDPProfilerHost = '127.0.0.1'; $wgUDPProfilerPort = '3811';

/** Detects non-matching wfProfileIn/wfProfileOut calls */ $wgDebugProfiling = true; /** Output debug message on every wfProfileIn/wfProfileOut */ $wgDebugFunctionEntry = 1; /** Lots of debugging output from SquidUpdate.php */ $wgDebugSquid = false; </php>

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

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