autodesk forge - Why is Viewer' getViewerToken getting called infinite times?

Question

The function getViewerToken is called infinitely since today without any code change. Is this bug on our side or a bug in the forge viewer?

        iframe.viewer = new iframe.Autodesk.Viewing.GuiViewer3D(iframe.viewerDiv, { extensions: extensions });
        let options = {
            // 'env': 'AutodeskProduction',
            'env': 'MD20ProdEU', //svf2
            'api': 'D3S', //svf2
            'getAccessToken': function(onTokenReady) {
                     ...
            };
  .....

question from:https://stackoverflow.com/questions/65952570/why-is-viewer-getviewertoken-getting-called-infinite-times

Answer 1

The viewer calls the getAccessToken function whenever the token needs to be refreshed. When you're calling the callback function inside getAccessToken, make sure that the second parameter (expiration time of the new token in seconds) is a positive integer number. Perhaps your code is passing in zero or a negative number, forcing the viewer to repeatedly ask for new tokens.