--- /dev/null
+<?php
+
+// must be called POST validation
+
+/**
+ * Adds target="blank" to all outbound links. This transform is
+ * only attached if Attr.TargetBlank is TRUE. This works regardless
+ * of whether or not Attr.AllowedFrameTargets
+ */
+class HTMLPurifier_AttrTransform_TargetBlank extends HTMLPurifier_AttrTransform
+{
+ /**
+ * @type HTMLPurifier_URIParser
+ */
+ private $parser;
+
+ public function __construct()
+ {
+ $this->parser = new HTMLPurifier_URIParser();
+ }
+
+ /**
+ * @param array $attr
+ * @param HTMLPurifier_Config $config
+ * @param HTMLPurifier_Context $context
+ * @return array
+ */
+ public function transform($attr, $config, $context)
+ {
+ if (!isset($attr['href'])) {
+ return $attr;
+ }
+
+ // XXX Kind of inefficient
+ $url = $this->parser->parse($attr['href']);
+ $scheme = $url->getSchemeObj($config, $context);
+
+ if ($scheme->browsable && !$url->isBenign($config, $context)) {
+ $attr['target'] = '_blank';
+ }
+ return $attr;
+ }
+}
+
+// vim: et sw=4 sts=4