strip_tags_long: use htmlpurifier to properly reformat html content

lib/htmlpurifier/library/HTMLPurifier/AttrTransform/BdoDir.php

@@ -0,0 +1,19 @@
+<?php
+
+// this MUST be placed in post, as it assumes that any value in dir is valid
+
+/**
+ * Post-trasnform that ensures that bdo tags have the dir attribute set.
+ */
+class HTMLPurifier_AttrTransform_BdoDir extends HTMLPurifier_AttrTransform
+{
+
+    public function transform($attr, $config, $context) {
+        if (isset($attr['dir'])) return $attr;
+        $attr['dir'] = $config->get('Attr', 'DefaultTextDir');
+        return $attr;
+    }
+
+}
+
+// vim: et sw=4 sts=4