API reference
Design
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Platform
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appProcess.registerOnMessage
API reference for the appProcess.registerOnMessage method.
Registers a callback that listens for broadcasted messages.
Parameters
callbackOnMessageCallbackRequiredThe callback that listens for broadcasted messages.
Parameters
senderobjectRequiredInformation about the process that sent the message.
- sender.appProcessId - The ID of the process that sent the message.
- sender.surface - The surface of the process that sent the message.
appProcessIdAppProcessIdRequiredThe unique identifier of an app process.
surfaceAppSurfaceRequiredThe type of surface on which an app process can run.
The possible surfaces include:
"headless"- A surface for when there is no visible user interface."object_panel"- A surface that renders a user interface in the side panel of the Canva editor."selected_image_overlay"- A surface that can be opened on top of a selected image.
Available values:
"object_panel""selected_image_overlay""headless"
messageanyRequiredThe broadcasted message.
Returns
Promise<void>
Returns
A disposer function that cleans up the registered callback.
() => Promise<void>