Handle DB_DataObject errors better

We try to handle DB_DataObject errors a little bit better. Previously,
they just spit out a cryptic string to the browser with a suggestion
to turn on debugging (not a good idea!). So, we catch the error, write
the full error message to the log, and then tell users that the can
contact the admins if they need to.

index.php

@@ -25,7 +25,8 @@ require_once INSTALLDIR . '/lib/common.php';
 $user = null;
 $action = null;
 
-function getPath($req) {
+function getPath($req)
+{
     if (common_config('site', 'fancy')) {
         return $req['p'];
     } else if ($_SERVER['PATH_INFO']) {
@@ -35,10 +36,30 @@ function getPath($req) {
     }
 }
 
-function main() {
+function handleError($error)
+{
+    common_log(LOG_ERR, "PEAR error: " . $error->getMessage());
+    $msg = sprintf(_('The database for %s isn\'t responding correctly, '.
+                     'so the site won\'t work properly. '.
+                     'The site admins probably know about the problem, '.
+                     'but you can contact them at %s to make sure. '.
+                     'Otherwise, wait a few minutes and try again.'),
+                   common_config('site', 'name'),
+                   common_config('site', 'email'));
 
+    $dac = new DBErrorAction($msg, 500);
+    $dac->showPage();
+    exit(-1);
+}
+
+function main()
+{
     global $user, $action;
 
+    // For database errors
+
+    PEAR::setErrorHandling(PEAR_ERROR_CALLBACK, 'handleError');
+
     // XXX: we need a little more structure in this script
 
     // get and cache current user

lib/dberroraction.php

@@ -0,0 +1,73 @@
+<?php
+/**
+ * DB error action.
+ *
+ * PHP version 5
+ *
+ * @category Action
+ * @package  Laconica
+ * @author   Evan Prodromou <evan@controlyourself.ca>
+ * @author   Zach Copley <zach@controlyourself.ca>
+ * @license  http://www.fsf.org/licensing/licenses/agpl.html AGPLv3
+ * @link     http://laconi.ca/
+ *
+ * Laconica - a distributed open-source microblogging tool
+ * Copyright (C) 2008, Controlez-Vous, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+if (!defined('LACONICA')) {
+    exit(1);
+}
+
+require_once INSTALLDIR.'/lib/servererroraction.php';
+
+/**
+ * Class for displaying DB Errors
+ *
+ * This only occurs if there's been a DB_DataObject_Error that's
+ * reported through PEAR, so we try to avoid doing anything that connects
+ * to the DB, so we don't trigger it again.
+ *
+ * @category Action
+ * @package  Laconica
+ * @author   Evan Prodromou <evan@controlyourself.ca>
+ * @license  http://www.fsf.org/licensing/licenses/agpl.html AGPLv3
+ * @link     http://laconi.ca/
+ */
+
+class DBErrorAction extends ServerErrorAction
+{
+    function __construct($message='Error', $code=500)
+    {
+        parent::__construct($message, $code);
+    }
+
+    function title()
+    {
+        return _('Database error');
+    }
+
+    function getLanguage()
+    {
+        // Don't try to figure out user's language; just show the page
+        return common_config('site', 'language');
+    }
+
+    function showPrimaryNav()
+    {
+        // don't show primary nav
+    }
+}

lib/htmloutputter.php

@@ -108,22 +108,26 @@ class HTMLOutputter extends XMLOutputter
         }
 
         header('Content-Type: '.$type);
-        
+
         $this->extraHeaders();
 
         $this->startXML('html',
                         '-//W3C//DTD XHTML 1.0 Strict//EN',
                         'http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd');
 
-        // FIXME: correct language for interface
-
-        $language = common_language();
+        $language = $this->getLanguage();
 
         $this->elementStart('html', array('xmlns' => 'http://www.w3.org/1999/xhtml',
                                           'xml:lang' => $language,
                                           'lang' => $language));
     }
 
+    function getLanguage()
+    {
+        // FIXME: correct language for interface
+        return common_language();
+    }
+
     /**
     *  Ends an HTML document
     *
@@ -134,7 +138,7 @@ class HTMLOutputter extends XMLOutputter
         $this->elementEnd('html');
         $this->endXML();
     }
-    
+
     /**
     *  To specify additional HTTP headers for the action
     *