Add load method for apps to bootstrap their panels

Signed-off-by: Julius Härtl <jus@bitgrid.net>

lib/private/Dashboard/Manager.php

@@ -23,11 +23,13 @@
 
 namespace OC\Dashboard;
 
+use InvalidArgumentException;
 use OCP\AppFramework\QueryException;
 use OCP\Dashboard\IManager;
 use OCP\Dashboard\IPanel;
 use OCP\ILogger;
 use OCP\IServerContainer;
+use Throwable;
 
 class Manager implements IManager {
 
@@ -46,7 +48,7 @@ class Manager implements IManager {
 
 	private function registerPanel(IPanel $panel): void {
 		if (array_key_exists($panel->getId(), $this->panels)) {
-			throw new \InvalidArgumentException('Dashboard panel with this id has already been registered');
+			throw new InvalidArgumentException('Dashboard panel with this id has already been registered');
 		}
 
 		$this->panels[$panel->getId()] = $panel;
@@ -88,6 +90,15 @@ class Manager implements IManager {
 					'level' => ILogger::FATAL,
 				]);
 			}
+
+			try {
+				$panel->load();
+			} catch (Throwable $e) {
+				\OC::$server->getLogger()->logException($e, [
+					'message' => 'Error during dashboard panel loading: ' . $e->getMessage(),
+					'level' => ILogger::FATAL,
+				]);
+			}
 		}
 		$this->lazyPanels = [];
 	}

lib/public/Dashboard/IPanel.php

@@ -32,32 +32,38 @@ namespace OCP\Dashboard;
 interface IPanel {
 
 	/**
-	 * @return string
+	 * @return string Unique id that identifies the panel, e.g. the app id
 	 * @since 20.0.0
 	 */
 	public function getId(): string;
 
 	/**
-	 * @return string
+	 * @return string User facing title of the panel
 	 * @since 20.0.0
 	 */
 	public function getTitle(): string;
 
 	/**
-	 * @return int
+	 * @return int Initial order for panel sorting
 	 * @since 20.0.0
 	 */
 	public function getOrder(): int;
 
 	/**
-	 * @return string
+	 * @return string css class that displays an icon next to the panel title
 	 * @since 20.0.0
 	 */
 	public function getIconClass(): string;
 
 	/**
-	 * @return string The absolute url to the apps own view
+	 * @return string|null The absolute url to the apps own view
 	 * @since 20.0.0
 	 */
-	public function getUrl(): string;
+	public function getUrl(): ?string;
+
+	/**
+	 * Execute panel bootstrap code like loading scripts and providing initial state
+	 * @since 20.0.0
+	 */
+	public function load(): void;
 }