Online Office UML Diagram

This is a UML sequence diagram illustrating the online Office document editing workflow, covering the entire process from opening and editing to saving a file. The process involves four key participants: the user, the business domain frontend, the online Office plugin, and the business domain backend. When the user clicks the "Edit Word Online" button, the frontend requests the raw Word document's Blob data stream from the backend and passes it to the Office plugin for initialization and rendering of the editing interface. After editing, the user clicks "Save"; the plugin generates a new Blob data stream and returns it via a callback interface. The frontend then calls the backend's save API to upload the new data. Once the backend validates and persists the data, the save result is propagated back through the layers, ultimately notifying the user that the save was successful.