Introduce class Icinga\Web\Helper\HtmlPurifier

refs #2641

library/Icinga/Web/Helper/HtmlPurifier.php

@@ -0,0 +1,93 @@
+<?php
+/* Icinga Web 2 | (c) 2018 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Web\Helper;
+
+use Closure;
+use InvalidArgumentException;
+
+class HtmlPurifier
+{
+    /**
+     * The actual purifier instance
+     *
+     * @var \HTMLPurifier
+     */
+    protected $purifier;
+
+    /**
+     * Create a new HtmlPurifier
+     *
+     * @param   array|Closure   $config     Additional configuration
+     */
+    public function __construct($config = null)
+    {
+        require_once 'HTMLPurifier/Bootstrap.php';
+        require_once 'HTMLPurifier.php';
+        require_once 'HTMLPurifier.autoload.php';
+
+        $purifierConfig = \HTMLPurifier_Config::createDefault();
+        $purifierConfig->set('Core.EscapeNonASCIICharacters', true);
+        $purifierConfig->set('Attr.AllowedFrameTargets', array('_blank'));
+        // This avoids permission problems:
+        // $purifierConfig->set('Core.DefinitionCache', null);
+        $purifierConfig->set('Cache.DefinitionImpl', null);
+        // TODO: Use a cache directory:
+        // $purifierConfig->set('Cache.SerializerPath', '/var/spool/whatever');
+        // $purifierConfig->set('URI.Base', 'http://www.example.com');
+        // $purifierConfig->set('URI.MakeAbsolute', true);
+
+        $this->configure($purifierConfig);
+
+        if ($config instanceof Closure) {
+            call_user_func($config, $purifierConfig);
+        } elseif (is_array($config)) {
+            $purifierConfig->loadArray($config);
+        } elseif ($config !== null) {
+            throw new InvalidArgumentException('$config must be either a Closure or array');
+        }
+
+        $this->purifier = new \HTMLPurifier($purifierConfig);
+    }
+
+    /**
+     * Apply additional default configuration
+     *
+     * May be overwritten by more concrete purifier implementations.
+     *
+     * @param   \HTMLPurifier_Config    $config
+     */
+    protected function configure($config)
+    {
+    }
+
+    /**
+     * Purify and return the given HTML string
+     *
+     * @param   string          $html
+     * @param   array|Closure   $config     Configuration to use instead of the default
+     *
+     * @return  string
+     */
+    public function purify($html, $config = null)
+    {
+        return $this->purifier->purify($html, $config);
+    }
+
+    /**
+     * Purify and return the given HTML string
+     *
+     * Convenience method to bypass object creation.
+     *
+     * @param   string          $html
+     * @param   array|Closure   $config     Additional configuration
+     *
+     * @return  string
+     */
+    public static function process($html, $config = null)
+    {
+        $purifier = new static($config);
+
+        return $purifier->purify($html);
+    }
+}