View source for Writing mediawiki extensions

Here is the simplest mediawiki extension you can write:

* in LocalSettings.php, add
 include("extensions/circlextension.php");
* create a file extensions/circlextension.php:
<pre>
<?php

$wgExtensionFunctions[] = "wfcirclextension";

function wfcirclextension()
{
  global $wgParser;
  $wgParser->setHook("circle", "circlehtml");
}

function circlehtml($code, $argv)
{
  $result="<svg><circle r=50 /></svg>";
  return $result;
}
</pre>
* Now you can create a mediawiki page with the content
 This is ''mediawiki-syntax''
 <circle this goes into argv >
 this goes into code
 </circle>
* And you will see a circle on the resulting wiki page. Note the circle may not be complete.

= Version 2 =
Version 2 could look like this:
<pre>
<?php

$wgExtensionFunctions[] = "wfcirclextension";

function wfcirclextension()
{
  global $wgParser;
  $wgParser->setHook("circle", "circlehtml");
}

function circlehtml($code, $argv)
{
  $param=reset($argv); # get first value of array
  if (!is_numeric($param)) {$param=20;};
  $result="
<svg width=".round($param*2)." height=".round($param*2).">
  <circle r=$param cx=$param cy=$param />
</svg>";
  $result=preg_replace("/\n/","",$result);
  return $result;
}</pre>

= Ideas =
* scale an image to the available size on the screen with the help of javascript

= See also =
* http://www.mediawiki.org/wiki/Extension:SimpleTable/1.2a - deliver mediawiki syntax, parsed
* http://stackoverflow.com/questions/2676388/how-can-i-add-per-page-permissions-to-a-user-in-mediawiki/2698312#2698312 - mediawiki on ACLs