[WIP] Notifications (#599)

Adds a new notifications feature to the Admin plugin. It will now lookup notifications which are set up on getgrav.org and will inform users, and also alert for new updates and provide awareness on various topics.

Also fixes issue with Array field in `value_only` mode, improperly displaying the key when novalue was set, and fixes issue with drag handlers in Array not showing/hiding properly (#950)

Updated FontAwesome to 4.6.3

classes/controller.php

@@ -338,6 +338,112 @@ class AdminController
         exit();
     }
 
+    protected function taskGetNewsFeed()
+    {
+        $cache = $this->grav['cache'];
+
+        if ($this->post['refresh'] == 'true') {
+            $cache->delete('news-feed');
+        }
+
+        $feed_data = $cache->fetch('news-feed');
+
+        if (!$feed_data) {
+            try {
+                $feed = $this->admin->getFeed();
+                if (is_object($feed)) {
+
+                    require_once(__DIR__ . '/../twig/AdminTwigExtension.php');
+                    $adminTwigExtension = new AdminTwigExtension();
+
+                    $feed_items = $feed->getItems();
+
+                    // Feed should only every contain 10, but just in case!
+                    if (count($feed_items > 10)) {
+                        $feed_items = array_slice($feed_items, 0, 10);
+                    }
+
+                    foreach($feed_items as $item) {
+                        $datetime =  $adminTwigExtension->adminNicetimeFilter($item->getDate()->getTimestamp());
+                        $feed_data[] = '<li><span class="date">'.$datetime.'</span> <a href="'.$item->getUrl().'" target="_blank" title="'.str_replace('"', '″', $item->getTitle()).'">'.$item->getTitle().'</a></li>';
+                    }
+                }
+
+                // cache for 1 hour
+                $cache->save('news-feed', $feed_data, 60*60);
+
+            } catch (\Exception $e) {
+                $this->admin->json_response = ['status' => 'error', 'message' => $e->getMessage()];
+                return;
+            }
+        }
+
+        $this->admin->json_response = ['status' => 'success', 'feed_data' => $feed_data];
+    }
+
+    /**
+     * Get Notifications from cache.
+     *
+     */
+    protected function taskGetNotifications()
+    {
+        $cache = $this->grav['cache'];
+        if (!(bool)$this->grav['config']->get('system.cache.enabled') || !$notifications = $cache->fetch('notifications')) {
+            //No notifications cache (first time)
+            $this->admin->json_response = ['status' => 'success', 'notifications' => [], 'need_update' => true];
+            return;
+        }
+
+        $need_update = false;
+        if (!$last_checked = $cache->fetch('notifications_last_checked')) {
+            $need_update = true;
+        } else {
+            if (time() - $last_checked > 86400) {
+                $need_update = true;
+            }
+        }
+
+        try {
+            $notifications = $this->admin->processNotifications($notifications);
+        } catch (\Exception $e) {
+            $this->admin->json_response = ['status' => 'error', 'message' => $e->getMessage()];
+            return;
+        }
+
+        $this->admin->json_response = ['status' => 'success', 'notifications' => $notifications, 'need_update' => $need_update];
+    }
+
+    /**
+     * Process Notifications. Store the notifications object locally.
+     *
+     * @return bool
+     */
+    protected function taskProcessNotifications()
+    {
+        $cache = $this->grav['cache'];
+
+        $data = $this->post;
+        $notifications = json_decode($data['notifications']);
+
+        try {
+            $notifications = $this->admin->processNotifications($notifications);
+        } catch (\Exception $e) {
+            $this->admin->json_response = ['status' => 'error', 'message' => $e->getMessage()];
+            return;
+        }
+
+        $show_immediately = false;
+        if (!$cache->fetch('notifications_last_checked')) {
+            $show_immediately = true;
+        }
+
+        $cache->save('notifications', $notifications);
+        $cache->save('notifications_last_checked', time());
+
+        $this->admin->json_response = ['status' => 'success', 'notifications' => $notifications, 'show_immediately' => $show_immediately];
+        return true;
+    }
+
     /**
      * Handle getting a new package dependencies needed to be installed
      *
@@ -348,6 +454,7 @@ class AdminController
         $data = $this->post;
         $packages = isset($data['packages']) ? $data['packages'] : '';
         $packages = (array)$packages;
+
         try {
             $this->admin->checkPackagesCanBeInstalled($packages);
             $dependencies = $this->admin->getDependenciesNeededToInstall($packages);
@@ -703,6 +810,39 @@ class AdminController
         return true;
     }
 
+    /**
+     * Clear the cache.
+     *
+     * @return bool True if the action was performed.
+     */
+    protected function taskHideNotification()
+    {
+        if (!$this->authorizeTask('hide notification', ['admin.login'])) {
+            return false;
+        }
+
+        $notification_id = $this->grav['uri']->param('notification_id');
+
+        if (!$notification_id) {
+            $this->admin->json_response = [
+                'status'  => 'error'
+            ];
+            return;
+        }
+
+        $filename = $this->grav['locator']->findResource('user://data/notifications/' . $this->grav['user']->username . YAML_EXT, true, true);
+        $file = CompiledYamlFile::instance($filename);
+        $data = $file->content();
+        $data[] = $notification_id;
+        $file->save($data);
+
+        $this->admin->json_response = [
+            'status'  => 'success'
+        ];
+
+        return true;
+    }
+
     /**
      * Handle the backup action
      *