Prefill Form with Query String Parameters

You can pass Query String parameters to the Form to pre fill fields. This can be used to, for instance, pre-select a value by changing the url with which you send users to the page containing the Form.

$(document).on("postRender.openform", function (event, control, moduleid, sf ) {
  var title = control.childrenByPropertyId["Sujet"];
    var sujet = getParameterByName('sujet');

function getParameterByName(name, url) {
  if (!url) url = window.location.href;
  name = name.replace(/[\[\]]/g, "\\$&");
  var regex = new RegExp("[?&]" + name + "(=([^&#]*)|&|#|$)"),
      results = regex.exec(url);
  if (!results) return null;
  if (!results[2]) return '';
  return decodeURIComponent(results[2].replace(/\+/g, " "));