Need to pause While loop

Question

I am using SharePoint 2013 in the cloud. Due to restrictions in the site, I am using JSOM and jQuery to customize a site.

I have modified a Document Library edit form to create Tasks for each person based on a list (Memo). I need to set the previously created Task (Memo Tasks) as a prerequisite to the next created task. When I try to use the SPServices.SPGetLastItemId, I get the previous item twice, but on the third item, it stops updating. My guess is, not enough time has passed between the save and when I am calling the Get Last Item Id.

Is there a way that I can pause the while loop to give the server time to save the previous record, before going on to the next one?

Here is an out-line of my code:

Get ClientContext
Get List "Approvers"
Create Query
var lastId = 0;
Load Get Items Query
Execute Query Async
   While moveNext()
     // this function creates the task
     createTask(title, user, dueDate, lastId);
     // then get the lastId
     lastId = $().SPServices.SPGetLastItemId({ listName: "Memo Tasks" });

I even tried putting a global variable in the createTask function, but it seems that the while loop continues on before that function has completed what it is doing.

Answer 1

The setTimer function didn't work in the long run, because I couldn't get the PreItemSave action to continue after everything was done.

I tried to do a Deferred Object to respond back with a final TRUE value to the PreItemSave at the end of the updates, but I found that it would just continue on after the initial Task creation.

My final solution was to use a checkbox that I already had in the form to run the script to do the creations and updates and then use a .click() to save the form and have it continue. I made a made a little more wordy post on my blog.

Here is the final code snippet.

// Get Group Routing list based off of selected value

function startGroupRouting(groupRouting) {

    var clientContext = new SP.ClientContext.get_current();
    var approveList = clientContext.get_web().get_lists().getByTitle('Approvers');
    var approveQuery = new SP.CamlQuery();

    var ql = '<View>' +
        '<Query>' +
            '<Where><Eq>' +
              '<FieldRef Name="Routing_x0020_Group" />' +
              '<Value Type="Text">' + groupRouting + '</Value>' +
            '</Eq></Where>' +
            '<OrderBy>' +
                '<FieldRef Name="Step" Ascending="false"></FieldRef>' +
            '</OrderBy>' +
        '</Query>' +
        '</View>';
    approveQuery.set_viewXml(ql);
    this.approveSelectList = approveList.getItems(approveQuery);
    clientContext.load(approveSelectList, 'Include(Approver,Approver_x0020_Type,Step)'); 

    clientContext.executeQueryAsync(
        Function.createDelegate(this, groupRouteSuccess),
        Function.createDelegate(this, onGetFail)
    );
}

// After Success, Create Each Task

function groupRouteSuccess() {
    var memoDeliverDate = $('nobr:contains("Deliver By")').closest('tr').find('input[title^="Deliver By"]').val();
    var approveGrpEnumerator = approveSelectList.getEnumerator();
    // loop through list items
    var i = 0;
    var listCount = approveSelectList.get_count();
    var lastMemoCnt = listCount - 1;
    var lastMemo = false;
    while(i < listCount) {
        approveGrpEnumerator.moveNext();
        if(i == lastMemoCnt) {
            lastMemo = true;
        }
        var thisGrpItem = approveGrpEnumerator.get_current();
        var approver = thisGrpItem.get_item('Approver');
        var approverType = new String(thisGrpItem.get_item('Approver_x0020_Type'));
        var step = new String(thisGrpItem.get_item('Step'));                        

        var clientContext = new SP.ClientContext.get_current();
        var oList = clientContext.get_web().get_lists().getByTitle('Memo Tasks');

        var today = new Date();
        var itemCreateInfo = new SP.ListItemCreationInformation();
        var oListItem = oList.addItem(itemCreateInfo);

        oListItem.set_item('Title', $.local.memoTitle + ' - ' + approverType);
        oListItem.set_item('Task_x0020_Group', $.local.memoTitle);
        oListItem.set_item('Step', step);
        oListItem.set_item('AssignedTo', approver);
        oListItem.set_item('Body', approverType);
        oListItem.set_item('DueDate', memoDeliverDate);
        oListItem.set_item('StartDate', today.format('M/dd/yyyy'));
        oListItem.update();

        clientContext.load(oListItem);
        if(i == lastMemoCnt){
            clientContext.executeQueryAsync(createFinalTaskSuccess, onGetFail);
        } else {
            clientContext.executeQueryAsync(createTaskSuccess(step), onGetFail);
        }
        i++;
    }
}

// Success for creating each task, except the last

function createTaskSuccess(step) {
    SP.UI.Notify.addNotification('New Task Created for Step ' + step);
}

// Success for creating each task, then start Task Update loop

function createFinalTaskSuccess() {
    SP.UI.Notify.addNotification('Final New Task Created');
    var clientContext = new SP.ClientContext.get_current();
    console.info("Starting Update Memo retrieve");
    var taskGrpList = clientContext.get_web().get_lists().getByTitle('Memo Tasks');
    var taskGrpQuery = new SP.CamlQuery();
    console.info("Query for Get Memos of taskGroup : " + $.local.memoTitle);
    var ql = '<View>' +
        '<Query>' +
            '<Where><Eq>' +
              '<FieldRef Name="Task_x0020_Group" />' +
              '<Value Type="Text">' + $.local.memoTitle + '</Value>' +
            '</Eq></Where>' +
            '<OrderBy>' +
                '<FieldRef Name="Step" Ascending="true"></FieldRef>' +
            '</OrderBy>' +
        '</Query>' +
        '</View>';
    taskGrpQuery.set_viewXml(ql);
    taskSelectGrpList = taskGrpList.getItems(taskGrpQuery);
    clientContext.load(taskSelectGrpList); 

    clientContext.executeQueryAsync(
        Function.createDelegate(this,
            function() {
                var clientContext = new SP.ClientContext.get_current();
                var updTaskGrpList = clientContext.get_web().get_lists().getByTitle('Memo Tasks');
                console.info("Approval Group retrieve success");
                var taskGrpEnumerator = taskSelectGrpList.getEnumerator();
                var listCount = taskSelectGrpList.get_count();
                var lastMemoCnt = listCount - 1;

                console.info("Update memos retrieved: " + listCount + " lastMemo cnt = " + lastMemoCnt);
                while(taskGrpEnumerator.moveNext()) {
                    var oListItem = taskGrpEnumerator.get_current();
                    $.local.memoArray.push(oListItem);
                }
                for(var x = 1; x < listCount; x++) {
                    console.info("task(" + x
                        + ") ID = " + $.local.memoArray[x].get_item('ID')
                        + " predID = " +  $.local.memoArray[x-1].get_item('ID')
                        + " isLastUpdate = " + $.local.isLastUpdate);
                    var taskItem = updTaskGrpList.getItemById($.local.memoArray[x].get_item('ID'));
                    taskItem.set_item('Predecessors', $.local.memoArray[x-1].get_item('ID'));
                    taskItem.update();

                    if(x == lastMemoCnt) {
                        clientContext.executeQueryAsync(updateFinalTaskSuccess($.local.memoArray[x].get_item('ID')), onGetFail);
                    } else {
                        clientContext.executeQueryAsync(updateTaskSuccess($.local.memoArray[x].get_item('ID')), onGetFail);
                    }
                }
            }
        ),
        Function.createDelegate(this, onGetFail)
    );
}

// Success for every Task update, except last one

function updateTaskSuccess(taskID) {
    SP.UI.Notify.addNotification('Task Predecessor Added to Task ' + taskID);
}

// Success for final Task Update

function updateFinalTaskSuccess() {
    SP.UI.Notify.addNotification('Task Predecessor Added to Final Task');
    console.info("Final Update Task Success");
    disableSaveBtn(false);
    $('input[name$="SaveItem"]').click();
}

// all fail

function onGetFail(sender, args) {
    var msgError = 'Request failed. ' + args.get_message() + '\n' + args.get_stackTrace();
    // add error message
    SP.UI.Notify.addNotification('Error : ' + args.get_message());
    console.error('Error occured: ' + msgError);
}

Answer 2

Here is code to make the thread wait for 3 seconds. Put this inside your while loop

var millisecondsToWait = 3000;
setTimeout(function() {
    // Whatever you want to do after 3 second sleep
}, millisecondsToWait);