MDL-30811 output: Add support for session notifications

2016-02-29 09:05:56 +08:00
parent 243468030a
commit 0346323cec
16 changed files with 622 additions and 55 deletions
@@ -0,0 +1,165 @@
+<?php
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle 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 General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
+
+namespace core;
+
+/**
+ * User Alert notifications.
+ *
+ * @package    core
+ * @copyright  2016 Andrew Nicols <[email protected]>
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+defined('MOODLE_INTERNAL') || die();
+
+class notification {
+    /**
+     * A notification of level 'success'.
+     */
+    const SUCCESS = 'success';
+
+    /**
+     * A notification of level 'warning'.
+     */
+    const WARNING = 'warning';
+
+    /**
+     * A notification of level 'info'.
+     */
+    const INFO = 'info';
+
+    /**
+     * A notification of level 'error'.
+     */
+    const ERROR = 'error';
+
+    /**
+     * Add a message to the session notification stack.
+     *
+     * @param string $message The message to add to the stack
+     * @param string $level   The type of message to add to the stack
+     */
+    public static function add($message, $level = null) {
+        global $PAGE, $SESSION;
+
+        if ($PAGE && $PAGE->state === \moodle_page::STATE_IN_BODY) {
+            // Currently in the page body - just render and exit immediately.
+            // We insert some code to immediately insert this into the user-notifications created by the header.
+            $id = uniqid();
+            echo \html_writer::span(
+                $PAGE->get_renderer('core')->render(new \core\output\notification($message, $level)),
+                '', array('id' => $id));
+
+            // Insert this JS here using a script directly rather than waiting for the page footer to load to avoid
+            // ensure that the message is added to the user-notifications section as soon as possible after it is created.
+            echo \html_writer::script(
+                    "(function() {" .
+                        "var notificationHolder = document.getElementById('user-notifications');" .
+                        "if (!notificationHolder) { return; }" .
+                        "var thisNotification = document.getElementById('{$id}');" .
+                        "if (!thisNotification) { return; }" .
+                        "notificationHolder.appendChild(thisNotification.firstChild);" .
+                        "thisNotification.remove();" .
+                    "})();"
+                );
+            return;
+        }
+
+        // Add the notification directly to the session.
+        // This will either be fetched in the header, or by JS in the footer.
+        $SESSION->notifications[] = (object) array(
+            'message'   => $message,
+            'type'      => $level,
+        );
+    }
+
+    /**
+     * Fetch all of the notifications in the stack and clear the stack.
+     *
+     * @return array All of the notifications in the stack
+     */
+    public static function fetch() {
+        global $SESSION;
+
+        if (!isset($SESSION) || !isset($SESSION->notifications)) {
+            return [];
+        }
+
+        $notifications = $SESSION->notifications;
+        $SESSION->notifications = [];
+
+        $renderables = [];
+        foreach ($notifications as $notification) {
+            $renderable = new \core\output\notification($notification->message, $notification->type);
+            $renderables[] = $renderable;
+        }
+
+        return $renderables;
+    }
+
+    /**
+     * Fetch all of the notifications in the stack and clear the stack.
+     *
+     * @return array All of the notifications in the stack
+     */
+    public static function fetch_as_array(\renderer_base $renderer) {
+        $notifications = [];
+        foreach (self::fetch() as $notification) {
+            $notifications[] = [
+                'template'  => $notification->get_template_name(),
+                'variables' => $notification->export_for_template($renderer),
+            ];
+        }
+        return $notifications;
+    }
+
+    /**
+     * Add a success message to the notification stack.
+     *
+     * @param string $message The message to add to the stack
+     */
+    public static function success($message) {
+        return self::add($message, self::SUCCESS);
+    }
+
+    /**
+     * Add a info message to the notification stack.
+     *
+     * @param string $message The message to add to the stack
+     */
+    public static function info($message) {
+        return self::add($message, self::INFO);
+    }
+
+    /**
+     * Add a warning message to the notification stack.
+     *
+     * @param string $message The message to add to the stack
+     */
+    public static function warning($message) {
+        return self::add($message, self::WARNING);
+    }
+
+    /**
+     * Add a error message to the notification stack.
+     *
+     * @param string $message The message to add to the stack
+     */
+    public static function error($message) {
+        return self::add($message, self::ERROR);
+    }
+}