Auto-incrementing value in Form.io

autoincrement.js

angular.module('myApp')
  .controller('FormController', ['$scope', 'Formio', function($scope, Formio) {
    $scope.form = null;
    $scope.submission = {data: {}};
    var formio = (new Formio('https://myproject.form.io/myform'));
    
    var getAutoIncrement = function(fieldName, cb) {
      formio.loadSubmissions({params: {sort: '-data.' + fieldName, limit: 1}}).then(function(subs) {
        var value = 0;
        if (subs.length) {
          value = parseInt(subs[0].data[fieldName], 10);
          value++;
        }
        cb(null, value);
      }, cb);
    };
    
    formio.loadForm().then(function(form) {
      $scope.form = form;
    });
    
    $scope.$on('formSubmission', function(event, submission) {
      getAutoIncrement('incrementingField', function(err, value) {
        if (err) { return }
        $scope.submission.data.incrementingField = value;
        formio.saveSubmission($scope.submission);
      });
    });
  });

form.html

<formio form="form" submission="submission"></formio>