model.Model.save() operation doesn't complete on beforeUnload

When adding a model.Model.save()  function to window.unload, the save() does not complete on the server side. I tested the code in the console outside of the unload function, and the save completes as expected.

I noticed that the jQuery deferred promise object returned by the mode save function remains in a 'pending' state forever. Why would this be?

Is there a fix?




Code is below if you want to reproduce the issue.

(function(skuid){ var $ = skuid.$;
$(document.body).one('pageload',function(){
$(window).unload(function(){
        try{
            
            removeUnfinishedRows();
            
        }
        catch(e){
            
            console.log(e);
            
        }
        
        debugger;
        });

});
})(skuid);
function removeUnfinishedRows(){
    
    var rowsToCheck = skuid.model.getModel('SubmissionsForSelectedBanks');
    var rowsToCheckData = rowsToCheck.data;
    
    //cancel changed since save() needs to be called in order to delete rows.
    //if save is called and changes aren't cancelled, some unintended changes may occur.
    rowsToCheck.cancel();
    
    //iterate thru each submission in the model that creates submissions and make sure that they've been sent
    //if they haven't been sent, mark them for deletion
    rowsToCheckData.forEach(
        
        function(element,index,array){
            
            rowToCheckTemp = rowsToCheckData[index];
            if(!rowToCheckTemp.Custom_Relationship__r.Form_Is_Incomplete__c){
                rowsToCheck.deleteRow({ Id: rowToCheckTemp.Id });
                
            }
        }
    );
    
    savePromise = rowsToCheck.save();
    console.log(savePromise); //this prints 'pending'
//only uncomment if you want your tab to crash. This while loop goes on forever
    /*while(savePromise.state()=='pending'){
        //do nothing... wait until promise is done failing or resolving
    }*/
    
}