feat: register a downloadCallback

Signed-off-by: silver <s.szmajduch@posteo.de>

[skip ci]

Author: silverkszlo

README.md

@@ -175,7 +175,16 @@ If you want to make your app compatible with this app, you can use the methods p
         ],
 
         // your vue component view
-        component: VideoView
+        component: VideoView,
+
+        // optional: callback to be called before download
+        // useful for saving unsaved changes, validation, logging, etc.
+        // if not provided, defaults to an empty function
+        downloadCallback: async (fileInfo) => {
+            // perform any pre-download operations
+            // e.g., save current editor state
+            await saveCurrentDocument(fileInfo)
+        }
     })
    ```
 3. Make sure your script is loaded with `\OCP\Util::addInitScript` so that the handler is registered **before** the viewer is loaded.
@@ -213,7 +222,16 @@ If you want to make your app compatible with this app, you can use the `OCA.View
         ],
 
         // your vue component view
-        component: VideoView
+        component: VideoView,
+
+        // optional: callback to be called before download
+        // useful for saving unsaved changes, validation, logging, etc.
+        // if not provided, defaults to an empty function
+        downloadCallback: async (fileInfo) => {
+            // perform any pre-download operations
+            // e.g., save current editor state
+            await saveCurrentDocument(fileInfo)
+        }
     })
    ```
 3. Make sure your script is loaded with `\OCP\Util::addScript` (in contrast to using the API package)!

src/services/Viewer.js

@@ -18,6 +18,7 @@ import logger from './logger.js'
  * @property {string} group group identifier to combine for navigating to the next/previous files
  * @property {?string} theme viewer modal theme (one of 'dark', 'light', 'default')
  * @property {boolean} canCompare Indicate support for comparing two files
+ * @property {?Function} downloadCallback Optional callback to be called before download
  */
 
 /**
@@ -89,6 +90,11 @@ export default class Viewer {
 			return
 		}
 
+		// Set default empty function for downloadCallback if not provided
+		if (!handler.downloadCallback) {
+			handler.downloadCallback = () => {}
+		}
+
 		this._state.handlers.push(handler)
 		const handledMimes = [
 			...handler.mimes,

src/views/Viewer.vue

@@ -1191,32 +1191,26 @@ export default defineComponent({
 		},
 
 		/**
-		 * Save active Text editors before downloading
+		 * Call handler's downloadCallback before downloading
 		 */
 		async onDownload() {
 			if (!this.canDownload) {
 				return
 			}
 
-			// Check if Text app is available and has active editor components
-			if (window.OCA?.Text?.editorComponents) {
+			// Get the current handler for this file
+			const mime = this.currentFile.mime
+			const alias = mime?.split('/')[0]
+			const handler = this.registeredHandlers[mime] ?? this.registeredHandlers[alias]
+
+			if (handler?.downloadCallback && typeof handler.downloadCallback === 'function') {
 				try {
-					logger.debug('Text app detected, attempting to save before download')
-
-					const editorComponents = window.OCA.Text.editorComponents
-
-					// Text app uses a Set to store editor components
-					if (editorComponents instanceof Set) {
-						for (const component of editorComponents) {
-							if (component && typeof component.save === 'function') {
-								logger.debug('Calling save on Text editor component')
-								await component.save()
-							}
-						}
-					}
+					logger.debug('Calling handler downloadCallback before download')
+					await handler.downloadCallback(this.currentFile)
 				} catch (error) {
-					logger.warn('Failed to save Text editor before download', { error })
-					// Continue with download anyway
+					logger.error('Failed to execute downloadCallback', { error })
+					showError(t('viewer', 'Failed to save file before download'))
+					return
 				}
 			}