Postmessage based live-preview

Summary The "Live Preview" is not so much live currently as it does not provide updated values without saving the record. There are plans for a [WebSocket based live-preview]( however I think a window.postMessage based approach could be both more reliable and easier to implement for end users like demonstrated here Basic Example Using the following snippet on the preview page the end user can start receiving events: Motivation I believe this to be a more resilient and easy to set up solution for pushing updates to the live preview pane. Where for a WebSocket based implementation you would need the end user to connect to the socket, authenticate, subscribe, handle disconnects on the preview page and configure the backend to properly route persistent WebSockets. While with this postMessage approach the data is pushed from the Directus App directly to the preview page in the browser without needing to connect over the network from either side. Detailed Design Instead…