Nested ClientContext executeQueryAsync() - sharepoint

Question

I have a requirement to change the value of a SharePoint List Workflow Status Column.
Lets assume we could have 2 to many workflow columns in one list (The below code works when a list has 1 workflow status column).
The issue is when it has multiple Workflow Status Column, it updates only the last column as there are nested executeQueryAsync calls.
I have tried the same with Deferred/Promise as well - see the second code block.
<script type="text/javascript">
ExecuteOrDelayUntilScriptLoaded(initialize, "sp.js");
//Get our objects
function initialize() {
var t0 = performance.now();
var context = new SP.ClientContext.get_current();
var web = context.get_web();
var list = web.get_lists().getById(_spPageContextInfo.pageListId)
var fieldCollection = list.get_fields();
var spField;
context.load(fieldCollection);
context.executeQueryAsync(Function.createDelegate(this, onFieldCollectionSucceeded), Function.createDelegate(this, onListDataFailed));
function onFieldCollectionSucceeded(sender, args) {
var fieldEnumerator = fieldCollection.getEnumerator();
while (fieldEnumerator.moveNext()) {
var field = fieldEnumerator.get_current();
var fType = field.get_fieldTypeKind();
//Value 28 correspond to SPWorkflowStatus
if (fType === 28) {
console.log(fieldEnumerator.get_current().get_title() + ": " + fType);
spField = field;
context.load(spField, "SchemaXml");
context.executeQueryAsync(Function.createDelegate(this, onFieldSucceeded), Function.createDelegate(this, onListDataFailed));
}
}
}
function onFieldSucceeded(sender, args) {
console.log("Schema changes processing for column: " + spField.get_title());
var schema = spField.get_schemaXml();
var newSchema = schema.replace('Abgelehnt', 'Rejected');
spField.set_schemaXml(newSchema);
spField.update();
context.executeQueryAsync(
Function.createDelegate(this, schemaChanged),
Function.createDelegate(this, onListDataFailed));
};
function schemaChanged(sender, args) {
console.log('Field Schema Updated');
}
function onListDataFailed(sender, args) {
console.log('List Data fetch failed. ' + args.get_message() + 'n' + args.get_stackTrace());
};
var t1 = performance.now();
console.log("Total Execution Time " + (t1 - t0) + " milliseconds.")
};
<script type="text/javascript">
//http://johnliu.net/blog/2015/12/convert-sharepoint-jsoms-executequeryasync-to-promise-in-the-prototype
ExecuteOrDelayUntilScriptLoaded(registerJsomPromise, "sp.js");
ExecuteOrDelayUntilScriptLoaded(initialize, "sp.js");
function initialize() {
var t0 = performance.now();
var context = new SP.ClientContext.get_current();
var web = context.get_web();
var list = web.get_lists().getById(_spPageContextInfo.pageListId)
var fieldCollection = list.get_fields();
var spField;
context.load(fieldCollection);
context.executeQueryAsync(Function.createDelegate(this, onFieldCollectionSucceeded), Function.createDelegate(this, onListDataFailed));
};
function onFieldCollectionSucceeded(sender, args) {
var fieldEnumerator = fieldCollection.getEnumerator();
while (fieldEnumerator.moveNext()) {
var field = fieldEnumerator.get_current();
var fType = field.get_fieldTypeKind();
//Value 28 correspond to SPWorkflowStatus
if (fType === 28) {
console.log(fieldEnumerator.get_current().get_title() + ": " + fType);
spField = field;
context.load(spField, "SchemaXml");
var promise = context.executeQuery();
setTimeout(function () { }, 500);
promise.done(function () {
console.log("Schema changes processing for column: " + spField.get_title());
var schema = spField.get_schemaXml();
var newSchema = setSchema(schema);
spField.set_schemaXml(newSchema);
spField.update();
context.load(spField);
context.executeQueryAsync(
Function.createDelegate(this, schemaChanged),
Function.createDelegate(this, onListDataFailed));
});
promise.then(function (sArgs) {
console.log('Field Schema Updated');
//sArgs[0] == success callback sender
//sArgs[1] == success callback args
}, function (fArgs) {
//fArgs[0] == fail callback sender
//fArgs[1] == fail callback args.
//in JSOM the callback args aren't used much -
//the only useful one is probably the get_message()
//on the fail callback
var failmessage = fArgs[1].get_message();
});
//context.executeQueryAsync(Function.createDelegate(this, onListDataSucceeded), Function.createDelegate(this, onListDataFailed));
}
}
}
function schemaChanged(sender, args) {
console.log('Field Schema Updated');
}
function onListDataFailed(sender, args) {
console.log('List Data fetch failed. ' + args.get_message() + 'n' + args.get_stackTrace());
};
var t1 = performance.now();
console.log("Total Execution Time " + (t1 - t0) + " milliseconds.")
function registerJsomPromise() {
SP.ClientContext.prototype.executeQuery = function () {
var deferred = $.Deferred();
this.executeQueryAsync(
function () { deferred.resolve(arguments); },
function () { deferred.reject(arguments); }
);
return deferred.promise();
};
}

Answer 1

The execute query async changes the state of iterator. This is why you have a weird behavior. You should load your fields, update those, and do one single execute at the end out of the while to actually update stuff. The only issue with that approach is that if you're code fails at some point, all the updates will be pending. So careful error handling is required.