I would like to refresh the Viewport (such that my onViewportRendered function gets called) from within a controller. The following code would get executed from an application event within one of the controllers.

This code fails with an error that the viewport does not have a function doLayout - I'm probably missing something really simple...

Code:
        // Refresh the viewport
        var viewport = this.application.getView('Viewport');
        if (!viewport) {
            console.warn('AppStarter.js onAccountAuthorization - The viewport is not available - this should not happen.');
        }
        else {
            console.log('AppStarter.js onAccountAuthorization - The viewport is available - refresh the viewport.');
            viewport.doLayout();
        }