Saving data via spaced update

The data persistence is achieved via the spaced update mechanism which is already present and needs to be integrated within the newly created type widgets.

First, the class must implement getData, in order to retrieve the data from the custom widget in a serialized form. As an example from the mind map implementation:

async getData() {
    const mind = this.mind;
    if (!mind) {
        return;
    }

    return {
        content: mind.getDataString()
    };
}

Here the content is a string containing a JSON. It is also possible to provide attachments here as well, such as SVG rendering to provide a preview of the content.

Then to trigger an update, register a listener within the custom widget that calls the spaced update, for example:

mind.bus.addListener("operation", (operation) => {
    this.spacedUpdate.scheduleUpdate();
});