How to pre-populate a form with data from another item ?

For information, here is my current script : 

"use strict";

var gTitle = "Title";
var gID = "ID";
var gSite = "Site";
var gRequester = "Requester";
var gTravelers = "Travelers";
var gManager = "Manager_x0020_Name";
var gDestCountry = "Destination_x0020_Country";
var gHSEApproReq = "HSE_x0020_Approval_x0020_Require";
var gCrewVisit = "Crew_x0020_Visit";
var gTelSatNumber = "TelSatNumber";
var gAccomodationDetails = "AccomodationDetails";
var gAgentContactDetails = "AgentContactDetails";
var gClient = "Client";
var gObjective = "Objective";
var gDepartDateToCountry = "Departure_x0020_Date_x0020_to_x0";
var gTripDescription = "Trip_x0020_Description_x0020__x0";
var gGPSCoordinates = "GPS_x0020_Coordinates";
var gDepartDateToCrew = "Departure_x0020_Date_x0020_to_x00";
var gTripToCrewDescription = "TriptoCrewDescription";
var gDepartDateFromCrew = "Departure_x0020_Date_x0020_from_";
var gReturnFromCrewDescription = "Return_x0020_from_x0020_Crew_x00";
var gDepartDateFromCountry = "Departure_x0020_Date_x0020_from_0";
var gReturnTripDescription = "Return_x0020_Trip_x0020_Descript";
var gComment = "Comment";
var gCopyAddresses = "Copy_x0020_Addresses";

var includes = gTitle + "," + gID + "," + gSite + "," + gRequester + "," + gTravelers + "," + gManager + "," + gDestCountry + "," + gHSEApproReq + "," + gCrewVisit + "," + gTelSatNumber + "," + gAccomodationDetails + "," + gAgentContactDetails + "," + gClient + "," + gObjective + "," + gDepartDateToCountry + "," + gTripDescription + "," + gGPSCoordinates + "," + gDepartDateToCrew + "," + gTripToCrewDescription + "," + gDepartDateFromCrew + "," + gReturnFromCrewDescription + "," + gDepartDateFromCountry + "," + gReturnTripDescription + "," + gComment + "," + gCopyAddresses;

var iSite;
var iRequester;
var iTravelers;
var iManager;
var iDestinationCountry;
var iHSERequired;
var iCrewVisit;
var iTelSatNumber;
var iAccomodationDetails;
var iAgentContactDetails;
var iClient;
var iObjective;
var iDepartDateToCountry;
var iTripDescription;
var iGPSCoordinates;
var iDepartDateToCrew;
var iTripToCrewDescription;
var iDepartDateFromCrew;
var iReturnFromCrewDescription;
var iDepartDateFromCountry;
var iReturnTripDescription;
var iComment;
var iCopyAddresses;

var tID;
var context;
var web;
var list;
var query;
var allItems;

function onQueryFailed(sender, args) {
console.log('Error: ' + args.get_message() + ' ' + args.get_stackTrace());
}

function setAllItemsOptions() {
var selectedSite = NWF$("#" + varSite + " option:selected");
var selectedSiteText = selectedSite.text();
var elID = NWF$("#" + fID);
NWF$("#" + fID + " option").remove();
NWF$(elID).append("<option selected='selected' value='INIT' data-nfchoicevalue='INIT'>INIT</option>");
var ListEnumerator = allItems.getEnumerator();
while (ListEnumerator.moveNext()) {
var currentItem = ListEnumerator.get_current();
var site = currentItem.get_item(gSite);
if (site == selectedSiteText) {
var iTitle = currentItem.get_item(gTitle);
var option = "<option value='" + iTitle + "' data-nfchoicevalue='" + iTitle + "'>" + iTitle + "</option>";
NWF$(elID).append(option);
}
}
}

function getListItemsFromSPList() {
context = new SP.ClientContext.get_current();
web = context.get_web();
list = web.get_lists().getByTitle("HSE");
query = SP.CamlQuery.createAllItemsQuery();
allItems = list.getItems(query);
context.load(allItems, "Include(" + includes + ")");
context.executeQueryAsync(setAllItemsOptions, onQueryFailed);
}

function setInfos() {
for(var nbi = 0; nbi < iTravelers.length; nbi++) {
if (NWF$("#" + varPreviousTravelers).val() == "") {
NWF$("#" + varPreviousTravelers).val(iTravelers[nbi].get_lookupValue());
} else {
NWF$("#" + varPreviousTravelers).val(NWF$("#" + varPreviousTravelers).val() + ", " + iTravelers[nbi].get_lookupValue());
}
}
var soption = NWF$("#" + varManager + " option[title='" + iManager.get_lookupValue() + "']");
var sindex = soption.prop("index");
var svalue = soption.prop("value");
NWF$("#" + varManager).prop("selectedIndex", sindex).val(svalue);
NWF$("#" + varManager).change();
NWF$("#" + varDestinationCountry + " option[value='" + iDestinationCountry + "']").attr('selected', 'selected');
if (iHSERequired == true) {
NWF$("#" + varHSERequired).click();
}
if (iCrewVisit == true) {
NWF$("#" + varCrewVisit).click();
}
NWF$("#" + varTelSatNumber).val(iTelSatNumber);
NWF$("#" + varAccomodationDetails).append(iAccomodationDetails);
NWF$("#" + varAccomodationDetails + "_inplacerte p").remove();
NWF$("#" + varAccomodationDetails + "_inplacerte").append(iAccomodationDetails);
NWF$("#" + varAgentContactDetails).append(iAgentContactDetails);
NWF$("#" + varAgentContactDetails + "_inplacerte p").remove();
NWF$("#" + varAgentContactDetails + "_inplacerte").append(iAgentContactDetails);
NWF$("#" + varClient).val(iClient);
NWF$("#" + varObjective).append(iObjective);
NWF$("#" + varObjective + "_inplacerte p").remove();
NWF$("#" + varObjective + "_inplacerte").append(iObjective);
var ddtcountry = new Date(iDepartDateToCountry);
var ddtcountrym = (ddtcountry.getMonth()+1) + "/" + (ddtcountry.getDate()) + "/" + (ddtcountry.getFullYear());
NWF$("#" + varDepartDateToCountry).attr("value", ddtcountrym);
NWF$("#" + varTripDescription).append(iTripDescription);
NWF$("#" + varTripDescription + "_inplacerte p").remove();
NWF$("#" + varTripDescription + "_inplacerte").append(iTripDescription);
NWF$("#" + varGPSCoordinates).val(iGPSCoordinates);
var ddtcrew = new Date(iDepartDateToCrew);
var ddtcrewm = (ddtcrew.getMonth()+1) + "/" + (ddtcrew.getDate()) + "/" + (ddtcrew.getFullYear());
NWF$("#" + varDepartDateToCrew).attr("value", ddtcrewm);
NWF$("#" + varTripCrewDescription).append(iTripToCrewDescription);
NWF$("#" + varTripCrewDescription + "_inplacerte p").remove();
NWF$("#" + varTripCrewDescription + "_inplacerte").append(iTripToCrewDescription);
var ddfcrew = new Date(iDepartDateFromCrew);
var ddfcrewm = (ddfcrew.getMonth()+1) + "/" + (ddfcrew.getDate()) + "/" + (ddfcrew.getFullYear());
NWF$("#" + varDepartDateFromCrew).attr("value", ddfcrewm);
NWF$("#" + varReturnFromCrewDescription).append(iReturnFromCrewDescription);
NWF$("#" + varReturnFromCrewDescription + "_inplacerte p").remove();
NWF$("#" + varReturnFromCrewDescription + "_inplacerte").append(iReturnFromCrewDescription);
var ddfcountry = new Date(iDepartDateFromCountry);
var ddfcountrym = (ddfcountry.getMonth()+1) + "/" + (ddfcountry.getDate()) + "/" + (ddfcountry.getFullYear());
NWF$("#" + varDepartDateFromCountry).attr("value", ddfcountrym);
NWF$("#" + varReturnFromTripDescription).append(iReturnTripDescription);
NWF$("#" + varReturnFromTripDescription + "_inplacerte p").remove();
NWF$("#" + varReturnFromTripDescription + "_inplacerte").append(iReturnTripDescription);
NWF$("#" + varComment).append(iComment);
NWF$("#" + varComment + "_inplacerte p").remove();
NWF$("#" + varComment + "_inplacerte").append(iComment);
if (iCopyAddresses) {
for(var nbi = 0; nbi < iCopyAddresses.length; nbi++) {
if (NWF$("#" + varPreviousCopyAddresses).val() == "") {
NWF$("#" + varPreviousCopyAddresses).val(iCopyAddresses[nbi].get_lookupValue());
} else {
NWF$("#" + varPreviousCopyAddresses).val(NWF$("#" + varPreviousCopyAddresses).val() + ", " + iCopyAddresses[nbi].get_lookupValue());
}
}
}
NWF$("#" + fID + " option[value='INIT']").attr('selected', 'selected');
}

function getInfos() {
var elID = NWF$("#" + fID + " option:selected");
tID = elID.text();
var ListEnumerator = allItems.getEnumerator();
while (ListEnumerator.moveNext()) {
var currentItem = ListEnumerator.get_current();
var iTitle = currentItem.get_item(gTitle);
if (iTitle == tID) {
iSite = currentItem.get_item(gSite);
iRequester = currentItem.get_item(gRequester);
iTravelers = currentItem.get_item(gTravelers);
iManager = currentItem.get_item(gManager);
iDestinationCountry = currentItem.get_item(gDestCountry);
iHSERequired = currentItem.get_item(gHSEApproReq);
iCrewVisit = currentItem.get_item(gCrewVisit);
iTelSatNumber = currentItem.get_item(gTelSatNumber);
iAccomodationDetails = currentItem.get_item(gAccomodationDetails);
iAgentContactDetails = currentItem.get_item(gAgentContactDetails);
iClient = currentItem.get_item(gClient);
iObjective = currentItem.get_item(gObjective);
iDepartDateToCountry = currentItem.get_item(gDepartDateToCountry);
iTripDescription = currentItem.get_item(gTripDescription);
iGPSCoordinates = currentItem.get_item(gGPSCoordinates);
iDepartDateToCrew = currentItem.get_item(gDepartDateToCrew);
iTripToCrewDescription = currentItem.get_item(gTripToCrewDescription);
iDepartDateFromCrew = currentItem.get_item(gDepartDateFromCrew);
iReturnFromCrewDescription = currentItem.get_item(gReturnFromCrewDescription);
iDepartDateFromCountry = currentItem.get_item(gDepartDateFromCountry);
iReturnTripDescription = currentItem.get_item(gReturnTripDescription);
iComment = currentItem.get_item(gComment);
iCopyAddresses = currentItem.get_item(gCopyAddresses);
}
}
setInfos();
}

NWF$(document).ready(function() {
getListItemsFromSPList();
});

NWF$("#" + varSite).on('change', function() {
setAllItemsOptions();
});

NB : This solution is uncomplete because I can't prepopulate the person fields.

the only way how you could get values from other list/item with OOTB functionality is to use calculated value control and lookup() function.

of course, calculated value control can not be edited.

not sure whether this would be an option for you.

to populate people picker field from javascript see following blog People Picker Extensions - Nintex Forms 

or search for some examples on forum https://community.nintex.com/search.jspa?q=%22NF.PeoplePickerApi%22&author=%2Fpeople%2F8567 

Hi ‌,

This is an interesting use case. It would be good to get on a call to understand your requirements better. This would assist us in building our upcoming technology.

Would you be open to a call with their myself or the UX team?

Cheers,

Euan

Hi ‌,

This is a great idea. 

Regards,

Thibault.

If you're having that conversation, I'd add that it would be really useful to be able to use a named control like a Calculated Value, as the default value for a control such as Textbox or similar. This would achieve the requirement here, and many more where you're trying to pull through data from another source into controls which may get edited.

Hi ,

Lets get on a call and have a chat about your thoughts on setting a field value similar to the calculated value control. I will send you an email.

Cheers,

Euan

Thanks for taking my call ‌. I appreciate your feedback and look forward to hearing how you go with our new responsive forms designer coming soon.

Cheers,

Euan

Thanks for taking my call Thibault Gauthier‌. Apologies I don't speak French, but hopefully my demo of the responsive forms designer speaks for itself!

I look forward to hearing how Experttime use the responsive forms in the future.

Cheers,

Euan

Pleasure, anytime. Great that Nintex is reaching out to it members like this and look forward to getting my hands on the new designer!

in the setInfo() function, what is "nbi" referring to?