How to make code wait x seconds before executing next iteration of loop in JS/ JQUery?

Question

I have already looked at the links like: Javascript - Wait 5 seconds before executing next line

and many others on stack overflow. Also I have tried using JS setTimeOut function for this.

I am trying to simulate a data bind in JS which comes from Web Service after every 3 seconds. This data is appended in a div after every time received from WebService.

But for testing and appending this data using JS, I need some function similar to Sleep(). setTimeOut works asynchronously so next iteration of loop start executing and doesn't wait. How can we achieve this in JS/JQuery.

Please check code snippet below:

linediagnosticsData = [];

linediagnosticsData.push({ Details: 'Complete - Go Live Date  Unavailable', ItemStatus: 'Tick', Title: 'Checking for Asset/Product Information' });
linediagnosticsData.push({ Details: 'Not Available', ItemStatus: 'Warning', Title: 'Line Length Summary - ' });
linediagnosticsData.push({ Details: 'Subscribers speed test results are over 31 days old', ItemStatus: 'Warning', Title: 'Line Summary' });
linediagnosticsData.push({ Details: 'Found (MPF Customer)', ItemStatus: 'Tick', Title: 'Checking for User Credentials' });
linediagnosticsData.push({ Details: 'No related incidents identified', ItemStatus: 'Tick', Title: 'Checking for Related Incidents - ' });
linediagnosticsData.push({ Details: 'The customer is subscribed for SMS updates.', ItemStatus: 'Tick', Title: 'Get Incident Subscribed' });
linediagnosticsData.push({ Details: 'Subscriber In Sync for 0 Day(s) 0 Hour(s) 0 Min(s) 0 Sec(s)', ItemStatus: 'Tick', Title: 'Checking for Sync' });
linediagnosticsData.push({ Details: 'Down(max) - 10928 kb/s Up(max) - 992 kb/s', ItemStatus: 'Warning', Title: 'Checking for Asset/Product Information' });
linediagnosticsData.push({ Details: 'Stable line', ItemStatus: 'Tick', Title: 'Checking line stability' });
linediagnosticsData.push({ Details: 'Subscriber has successfully authenticated', ItemStatus: 'Tick', Title: 'Checking for an IP Address...' });
linediagnosticsData.push({ Details: 'Subscriber has successfully connected to the network. Unable to identify any issues on this line.', ItemStatus: 'Tick', Title: 'Checking for an IP Address - Subscriber has been successfully issued an IP of 192.180.222.1' });


   for (var i = 0; i < linediagnosticsData.length; i++) {
        debugger;
        var imageURL = "/supportalcore/InternalImages/";
        switch ((linediagnosticsData[i].ItemStatus).toLowerCase()) {
            case "tick":
                imageURL = imageURL + "tick.gif";
                break;
            case "warning":
                imageURL = imageURL + "warning.gif";
                break;
            case "cross":
                imageURL = imageURL + "cross.gif";
                break;
            default:
                break;

        }
        var html =
         "<div class='nameValueImagerow'>"
        + "<div class='c1'>" + linediagnosticsData[i].Title + "</div>"
        + "<div class='c2'>" + linediagnosticsData[i].Details + "</div>"
        + "<div class='c3'>" + "<img src=" + imageURL + " alt='i'  />" + "</div>"
        + "<div class='c4'></div>"
        + "</div>";

        lineDiagnosticsBox.append(html);
        //To add wait/ Sleep so that next statement gets executed after some seconds
    }

I have commented the line where I want to add delay/wait/sleep.

Answer 1

• You can use function instead of for to imitate loop.
• Usage of setTimeout allows to execute next "iteration" after required delay.

Fiddle.

var lineDiagnosticsBox = $('body');
var linediagnosticsData = [];
linediagnosticsData.push({ Details: 'Complete - Go Live Date  Unavailable', ItemStatus: 'Tick', Title: 'Checking for Asset/Product Information' });
linediagnosticsData.push({ Details: 'Not Available', ItemStatus: 'Warning', Title: 'Line Length Summary - ' });

(function loop(i) {
    var imageURL = "/supportalcore/InternalImages/";
    switch ((linediagnosticsData[i].ItemStatus).toLowerCase()) {
        case "tick":
            imageURL = imageURL + "tick.gif";
            break;
        case "warning":
            imageURL = imageURL + "warning.gif";
            break;
        case "cross":
            imageURL = imageURL + "cross.gif";
            break;
        default:
            break;            
    }
    var html = "<div class='nameValueImagerow'>"
        + "<div class='c1'>" + linediagnosticsData[i].Title + "</div>"
        + "<div class='c2'>" + linediagnosticsData[i].Details + "</div>"
        + "<div class='c3'>" + "<img src=" + imageURL + " alt='i'  />" + "</div>"
        + "<div class='c4'></div>"
        + "</div>";
    lineDiagnosticsBox.append(html);
    i++;
    if (i < linediagnosticsData.length)
    {
        setTimeout(function() { loop(i); }, 3000);
    }
})(0);