When running a Matlab web App, how do I run cleanup code upon the browser tab closing?

I have compiled an App Designer app to run as a web app in a browser, using the Matlab Web App Server. When running a normal app, one can put cleanup code in the FormClosing callback, such that it runs when the app is closed. However, closing a web app tab in a browser does not call this callback. Is there a way to have Matlab code run automatically when the app tab is closed?

Answer 1

[Sreeram]

Hi Eyal,

I understand that the "CloseRequestFcn" which is properly triggered when running an app in MATLAB, does not get triggered when the app is deployed as a web app and closed in the browser.

It is a documented limitation that the "CloseRequestFcn" property has not effect in web apps:

https://www.mathworks.com/help/webappserver/ug/unsupported-functionality.html#mw_af4907e7-7639-420e-9de4-330df17cd531

As a potential workaround, you can register a "DeleteFcn" callback for your "uifigure", which will be called whenever the web app is closed. To do this, add the following line to "startupFcn":

app.UIFigure.DeleteFcn = createCallbackFcn(app, @deleteFcn, true);

and then create a function called "deleteFcn" in your app like this:

function deleteFcn(app, event)
    % put your logic here that would otherwise be in CloseRequestFcn
end

I hope this workaround helps!

Best regards,

Sreeram

[Eyal Doron]

It worked perfectly! Thanks