Prompted by Cassy Freeman and this question raised by Chintan Desai, 2 workflow instance executes at same time, I thought I would share how I got around this very problem.
My scenario is slightly different as I wanted the new reference number displayed on the new form for users info even before the record saved. Initially i thought us JavaScript to get the next number from the GenerateID list and then use workflow on save to increment the next number.
This actually made Murphy's law (read the rest of the comments on the question!!) more likely to happen which was pointed out to me by Cassy Freeman in a workshop so i had to come up with something else.
Solution:
When the new form is loaded use Javascript to get the next number and then increment by one and then write back to the GenerateID list immediately. This will ensure that the next number will be different and therefore no chance of Murphy getting his way!!!
The fun part:
Title field set to have a Client ID JavaScipt variable of varReference.
Title field has a rule on it to be disable when populated using the formula not(isNullOrEmpty({Self})).
Second field on the form set to have a Client ID JavaScipt variable of varSecondField. (Change as required)
The really fun part (!?!?!):
Custom JavaScript to do the rest.
//Ensure form is initialised
NWF.FormFiller.Events.RegisterAfterReady(function () {
NWF$(document).ready(function () {
//Ensure required files loaded
ExecuteOrDelayUntilScriptLoaded(GetNextNumber, 'sp.js');
});
});
function GetNextNumber() {
//Get reference value
var reference = NWF$('#' + varReference).val();
//Ensure current reference is empty (new item)
if (reference == '') {
jQuery('#errorMsg').empty();
jQuery('#outputData').empty();
//Get Next Number from GenerateID list
var requestUri = _spPageContextInfo.webAbsoluteUrl + '/_api/Web/Lists/getByTitle('GenerateID')/items?$select=Id,Title';
try {
jQuery.ajax({
url: requestUri,
type: 'GET',
headers: { 'ACCEPT': 'application/json;odata=verbose' },
success: ReferenceGetSuccess,
error: ReferenceGetError
});
}
catch (err) {
jQuery('#errorMsg').html('getListData Error: ' + err);
}
}
}
function ReferenceGetSuccess(data) {
//Ensure data returned
if (data.d.results.length > 0) {
//Update Title column to the Next Number
NWF$('#' + varReference).val(data.d.results[0].Title);
//Give Title column focus
NWF$('#' + varReference).focus();
//Give second field focus to invoke the rule on the Title field to disable if populated
NWF$('#' + varSecondField).focus();
//Convert next number value to a number
var nextNumber = parseInt(data.d.results[0].Title);
//Increment the number by 1
nextNumber = nextNumber + 1;
//Get current context
var ctx = new SP.ClientContext(_spPageContextInfo.webAbsoluteUrl);
//Get the GenerateID list
var oList = ctx.get_web().get_lists().getByTitle('GenerateID');
//Get the item by id
var oListItem = oList.getItemById(1);
//Udpdate the item to the incemented number
oListItem.set_item('Title', nextNumber);
//Commit the update
oListItem.update();
ctx.executeQueryAsync(Function.createDelegate(this, onQuerySucceeded), Function.createDelegate(this, onQueryFailed));
}
}
function ReferenceGetError() {
alert('Failed to load Lookup Items');
}
function onQuerySucceeded() {
//Do post processing if required
}
function onQueryFailed(sender, args) {
alert('Request failed. ' + args.get_message() + '
' + args.get_stackTrace());
}
Now you have an immediately incrementing number so duplicates can be avoided.
Video: Writing Custom JavaScript In Nintex Forms for SharePoint
Hope this helps.
