strip_tags_long: use htmlpurifier to properly reformat html content

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

@@ -0,0 +1,44 @@
+<?php
+
+/**
+ * Pre-transform that changes deprecated hspace and vspace attributes to CSS
+ */
+class HTMLPurifier_AttrTransform_ImgSpace extends HTMLPurifier_AttrTransform {
+
+    protected $attr;
+    protected $css = array(
+        'hspace' => array('left', 'right'),
+        'vspace' => array('top', 'bottom')
+    );
+
+    public function __construct($attr) {
+        $this->attr = $attr;
+        if (!isset($this->css[$attr])) {
+            trigger_error(htmlspecialchars($attr) . ' is not valid space attribute');
+        }
+    }
+
+    public function transform($attr, $config, $context) {
+
+        if (!isset($attr[$this->attr])) return $attr;
+
+        $width = $this->confiscateAttr($attr, $this->attr);
+        // some validation could happen here
+
+        if (!isset($this->css[$this->attr])) return $attr;
+
+        $style = '';
+        foreach ($this->css[$this->attr] as $suffix) {
+            $property = "margin-$suffix";
+            $style .= "$property:{$width}px;";
+        }
+
+        $this->prependCSS($attr, $style);
+
+        return $attr;
+
+    }
+
+}
+
+// vim: et sw=4 sts=4