====== Debugging PHP ======

In the absence of an IDE (and particularly in a complex OO application like Dokuwiki) it's useful to be able to establish how you reached a particular point in the code. You can do this by acquiring a stack trace of the current call stack:

<code php>ob_start();
var_dump(debug_backtrace());
$result = ob_get_clean();
</code>
You can then output ''$result'' to the browser or to a log file. 

Similarly when catching an exception:
<code php>try {

  // do something that causes an exception
  
}
catch (Exception $e) {
  ob_start();
  var_dump($e->getTrace());
  $result = ob_get_clean();
  
  // ... then report $result somehow, e.g. by writing to a log file
  
}
</code>

===== Dokuwiki log file =====
To write it to the Dokuwiki log file:
  - set config option ''allowdebug'';
  -- write ''$result'' to ''data/cache/debug.log'' (see [[https://www.dokuwiki.org/devel:debugging|Debug Tools]]) with:
  .. <code php>dbglog($result);</code> 


{{tag> php dokuwiki}}