--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/plugins/help/help.php	Thu Jan 04 15:50:29 2018 -0500
@@ -0,0 +1,164 @@
+<?php
+
+/**
+ * Roundcube Help Plugin
+ *
+ * @author Aleksander 'A.L.E.C' Machniak
+ * @author Thomas Bruederli <thomas@roundcube.net>
+ * @license GNU GPLv3+
+ *
+ * Configuration (see config.inc.php.dist)
+ * 
+ **/
+
+class help extends rcube_plugin
+{
+    // all task excluding 'login' and 'logout'
+    public $task = '?(?!login|logout).*';
+    // we've got no ajax handlers
+    public $noajax = true;
+    // skip frames
+    public $noframe = true;
+
+    function init()
+    {
+        $this->load_config();
+        $this->add_texts('localization/', false);
+
+        // register task
+        $this->register_task('help');
+
+        // register actions
+        $this->register_action('index', array($this, 'action'));
+        $this->register_action('about', array($this, 'action'));
+        $this->register_action('license', array($this, 'action'));
+
+        $this->add_hook('startup', array($this, 'startup'));
+        $this->add_hook('error_page', array($this, 'error_page'));
+    }
+
+    function startup($args)
+    {
+        $rcmail = rcmail::get_instance();
+
+        // add taskbar button
+        $this->add_button(array(
+            'command'    => 'help',
+            'class'      => 'button-help',
+            'classsel'   => 'button-help button-selected',
+            'innerclass' => 'button-inner',
+            'label'      => 'help.help',
+        ), 'taskbar');
+
+        $this->include_script('help.js');
+        $rcmail->output->set_env('help_open_extwin', $rcmail->config->get('help_open_extwin', false), true);
+
+        // add style for taskbar button (must be here) and Help UI
+        $skin_path = $this->local_skin_path();
+        if (is_file($this->home . "/$skin_path/help.css")) {
+            $this->include_stylesheet("$skin_path/help.css");
+        }
+    }
+
+    function action()
+    {
+        $rcmail = rcmail::get_instance();
+
+        // register UI objects
+        $rcmail->output->add_handlers(array(
+            'helpcontent' => array($this, 'content'),
+            'tablink' => array($this, 'tablink'),
+        ));
+
+        if ($rcmail->action == 'about')
+            $rcmail->output->set_pagetitle($this->gettext('about'));
+        else if ($rcmail->action == 'license')
+            $rcmail->output->set_pagetitle($this->gettext('license'));
+        else
+            $rcmail->output->set_pagetitle($this->gettext('help'));
+
+        $rcmail->output->send('help.help');
+    }
+
+    function tablink($attrib)
+    {
+        $rcmail = rcmail::get_instance();
+
+        $attrib['name'] = 'helplink' . $attrib['action'];
+        $attrib['href'] = $rcmail->url(array('_action' => $attrib['action'], '_extwin' => !empty($_REQUEST['_extwin']) ? 1 : null));
+
+        // title might be already translated here, so revert to it's initial value
+        // so button() will translate it correctly
+        $attrib['title'] = $attrib['label'];
+
+        return $rcmail->output->button($attrib);
+    }
+
+    function content($attrib)
+    {
+        $rcmail = rcmail::get_instance();
+
+        switch ($rcmail->action) {
+            case 'about':
+                if (is_readable($this->home . '/content/about.html')) {
+                    return @file_get_contents($this->home . '/content/about.html');
+                }
+                $default = $rcmail->url(array('_task' => 'settings', '_action' => 'about', '_framed' => 1));
+                $src     = $rcmail->config->get('help_about_url', $default);
+                break;
+
+            case 'license':
+                if (is_readable($this->home . '/content/license.html')) {
+                    return @file_get_contents($this->home . '/content/license.html');
+                }
+                $src = $rcmail->config->get('help_license_url', 'http://www.gnu.org/licenses/gpl-3.0-standalone.html');
+                break;
+
+            default:
+                $src = $rcmail->config->get('help_source');
+
+                // resolve task/action for depp linking
+                $index_map = $rcmail->config->get('help_index_map', array());
+                $rel = $_REQUEST['_rel'];
+                list($task,$action) = explode('/', $rel);
+                if ($add = $index_map[$rel])
+                    $src .= $add;
+                else if ($add = $index_map[$task])
+                    $src .= $add;
+                break;
+        }
+
+        // default content: iframe
+        if (!empty($src)) {
+            $attrib['src'] = $this->resolve_language($src);
+        }
+
+        if (empty($attrib['id']))
+            $attrib['id'] = 'rcmailhelpcontent';
+
+        $attrib['name'] = $attrib['id'];
+
+        return $rcmail->output->frame($attrib);
+    }
+
+    function error_page($args)
+    {
+        $rcmail = rcmail::get_instance();
+
+        if ($args['code'] == 403 && $rcmail->request_status == rcube::REQUEST_ERROR_URL && ($url = $rcmail->config->get('help_csrf_info'))) {
+            $args['text'] .= '<p>' . html::a(array('href' => $url, 'target' => '_blank'), $this->gettext('csrfinfo')) . '</p>';
+        }
+
+        return $args;
+    }
+
+    private function resolve_language($path)
+    {
+        // resolve language placeholder
+        $rcmail  = rcmail::get_instance();
+        $langmap = $rcmail->config->get('help_language_map', array('*' => 'en_US'));
+        $lang    = $langmap[$_SESSION['language']] ?: $langmap['*'];
+
+        return str_replace('%l', $lang, $path);
+    }
+}