Implement Pixels attribute definition.

git-svn-id: http://htmlpurifier.org/svnroot/htmlpurifier/trunk@169 48356398-32a2-884e-a903-53898d9a118a

library/HTMLPurifier/AttrDef/Pixels.php

@@ -0,0 +1,30 @@
+<?php
+
+require_once 'HTMLPurifier/AttrDef.php';
+
+class HTMLPurifier_AttrDef_Pixels extends HTMLPurifier_AttrDef
+{
+    
+    function validate($string) {
+        
+        $string = trim($string);
+        if ($string === '0') return $string;
+        if ($string === '')  return false;
+        $length = strlen($string);
+        if (substr($string, $length - 2) == 'px') {
+            $string = substr($string, 0, $length - 2);
+        }
+        if (!is_numeric($string)) return false;
+        $int = (int) $string;
+        
+        if ($int < 0) return '0';
+        
+        // could use some upper-bound checking
+        
+        return (string) $int;
+        
+    }
+    
+}
+
+?>