QuickUpload custom submit

Cannot override submit, to do ajax progress on file upload.

If we just override submit like in the code above, no event (first argument `evt`) will be passed to function. And we cannot use submit events like form.$.onsubmit, because it's overriden to.

If there are custom event like onSubmit (same as onLoad, onShow & etc.) that not specified in documentation ? Or may be we can pass form submit event to overriden submit handler ?

...
          elements : [
            {
              type: 'file',
              id : 'upload',
              label : '',
              size: 38,
              setup : function( data ) {
                            var inputFile = this.getInputElement();
                             var form = inputFile.getAscendant('form');
                              form.$.submit = function(evt){  
                                ...
                               }
              }
             }
           ]
...