code: function updateSubmissionFile(req, res, next) {
    var fileUpdateOptions = req.appformsResultPayload.data;
  
    fileUpdateOptions.submission = {
      submissionId: req.params.id,
      fieldId: req.params.fieldId
    };
  
    //Remove the cached file when finished
    fileUpdateOptions.keepFile = false;
  
    //Adding A New File If Required
    fileUpdateOptions.addingNewSubmissionFile = req.addingNewSubmissionFile;
  
    //If not adding a new file, the fileId param is expected to be the file group id
    if (!fileUpdateOptions.addingNewSubmissionFile) {
      fileUpdateOptions.fileDetails.groupId = req.params.fileId;
    } else {
      fileUpdateOptions.fileDetails.hashName = req.params.fileId;
    }
  
    logger.debug("Middleware updateSubmissionFile ", {fileUpdateOptions: fileUpdateOptions});
  
    forms.updateSubmissionFile(_.extend(fileUpdateOptions, req.connectionOptions), submissionsHandler(constants.resultTypes.submissions, req, next));
  }
docs: Update A Single Submission File
  @param req
  @param res
  @param next