When a customer sends a message from a client app that includes a link, Link preview enables to provide a preview text or a thumbnail image of the link. In this way, a sender and a receiver of the message can be aware of what they're going to see before they open the link.
To provide a link preview by updating a message, every user message sent from a client app should be checked if it includes any URLs.
Implement the code to extract a URL from a customer's message and pass it to Sendbird server. When the server sends the parsed data, set it as a
JSON object and stringify the object. Pass the stringified
JSON object as an argument to a parameter in the
Note: Go to the GitHub page and refer to the
UrlPreviewAsyncTaskclass in the sample code. You'll get an idea on how to implement methods of the above sample code, such as the
toJsonString(), which aren't actual code but are intended to help you understand the overall flow to provide link previews.
As a result, the original message is updated with a URL preview through the
onMessageUpdated() method of the channel event handler, and a sender and a receiver of the message can see a link preview on their app or a web.
In the channel event handler's
onMessageUpdated() method, you can find the data for a URL preview in the
message.data property as below: