First steps to using exceptions for error handling

Added two exception classes: one for client errors (= user can fix) and
one for server errors (only admin or coder can fix). The web entry point
now tries to catch exceptions and show them in the browser. The main
code for showing errors in Action class now throws an exception and lets
top-level handle it.

diff --git a/lib/clientexception.php b/lib/clientexception.php
new file mode 100644 (file)
index 0000000..3020d7f
--- /dev/null
+++ b/lib/clientexception.php
@@ -0,0 +1,56 @@
+<?php
+/**
+ * Laconica, the distributed open-source microblogging tool
+ *
+ * class for a client exception (user error)
+ *
+ * PHP version 5
+ *
+ * LICENCE: 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/>.
+ *
+ * @category  Exception
+ * @package   Laconica
+ * @author    Evan Prodromou <evan@controlyourself.ca>
+ * @copyright 2008 Control Yourself, Inc.
+ * @license   http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
+ * @link      http://laconi.ca/
+ */
+
+if (!defined('LACONICA')) {
+    exit(1);
+}
+
+/**
+ * Class for client exceptions
+ *
+ * Subclass of PHP Exception for user errors.
+ *
+ * @category Exception
+ * @package  Laconica
+ * @author   Evan Prodromou <evan@controlyourself.ca>
+ * @license  http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
+ * @link     http://laconi.ca/
+ */
+
+class ClientException extends Exception
+{
+    public function __construct($message = null, $code = 400) {
+        parent::__construct($message, $code);
+    }
+
+    // custom string representation of object
+    public function __toString() {
+        return __CLASS__ . ": [{$this->code}]: {$this->message}\n";
+    }
+}

diff --git a/lib/serverexception.php b/lib/serverexception.php
new file mode 100644 (file)
index 0000000..b8ed684
--- /dev/null
+++ b/lib/serverexception.php
@@ -0,0 +1,55 @@
+<?php
+/**
+ * Laconica, the distributed open-source microblogging tool
+ *
+ * class for a server exception (user error)
+ *
+ * PHP version 5
+ *
+ * LICENCE: 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/>.
+ *
+ * @category  Exception
+ * @package   Laconica
+ * @author    Evan Prodromou <evan@controlyourself.ca>
+ * @copyright 2008 Control Yourself, Inc.
+ * @license   http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
+ * @link      http://laconi.ca/
+ */
+
+if (!defined('LACONICA')) {
+    exit(1);
+}
+
+/**
+ * Class for server exceptions
+ *
+ * Subclass of PHP Exception for server errors. The user typically can't fix these.
+ *
+ * @category Exception
+ * @package  Laconica
+ * @author   Evan Prodromou <evan@controlyourself.ca>
+ * @license  http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
+ * @link     http://laconi.ca/
+ */
+
+class ServerException extends Exception
+{
+    public function __construct($message = null, $code = 400) {
+        parent::__construct($message, $code);
+    }
+
+    public function __toString() {
+        return __CLASS__ . ": [{$this->code}]: {$this->message}\n";
+    }
+}