Formatting a Date from a SharePoint List using Javascript and Momentjs

Question

I'm querying a SharePoint list using a JavaScript file and returning the results to a HTML page. All the results are coming back fine, but the results from the date column 'DeviceAvailableFrom' is coming back as NaN (aka Not a Number).

I'm using the Moment.js library but I'm new to it so don't know wuite how to format the var line. I want the date to come out DD-MM-YY. The current code which is returning the NaN is:

 var LifeCycleStart = new Date(item.DeviceAvailableFrom); 

How would I work the Moment formatting in to get the desired results?

Thanks for any help.

Answer 1

If DeviceAvailableFrom has the right values but in the wrong format, you can wrap & format it with moment on the next line.

var LifeCycleStart = new Date(item.DeviceAvailableFrom);
var wrapper = moment(wrapper).format("DD-MM-YY");

I haven't tested the script.

Edit: Ty Danny '365CSI' Engelman for pointing out the double-conversion.

Answer 2

If the date is blank it is not a Number

var LifeCycleStart = item.DeviceAvailableFrom;
if (LifeCycleStart) LifeCycleStart=new Date(item.DeviceAvailableFrom); 

And you don't need MomentJS

SharePoint adds a String.format function
so you can use:

String.format('{0:dd}-{0:MM}-{0:yyyy}',new Date('2015-10-07T20:39:54Z'));

Note: String.format is defined in msajaxbundle.js, loaded even before most of the JavaScript files so safe to use without SOD requirements or anything.
It was modelled after the C# and VB implementations, so the MSDN documentation applies
(for the major part; it does not do the alignment stuff as that makes no sense in HTML)

String.format("{0:i}",new Date());  outputs: Wed Oct 07 2015 20:39:54 GMT+0200 (W. Europe Daylight Time)
String.format("{0:F}",new Date());  outputs: Wednesday, 07 October 2015 20:39:54
String.format("{0:f}",new Date());  outputs: Wednesday, 07 October 2015 20:39
String.format("{0:D}",new Date());  outputs: Wednesday, 07 October 2015
String.format("{0:s}",new Date());  outputs: 2015-10-07T20:39:54
String.format("{0:d}",new Date());  outputs: 10/07/2015
String.format("{0:dd}",new Date());  outputs: 07
String.format("{0:ddd}",new Date());  outputs: Wed
String.format("{0:dddd}",new Date());  outputs: Wednesday
String.format("{0:m}",new Date());  outputs: October 07
String.format("{0:M}",new Date());  outputs: October 07
String.format("{0:MM}",new Date());  outputs: 10
String.format("{0:MMM}",new Date());  outputs: Oct
String.format("{0:MMMM}",new Date());  outputs: October
String.format("{0:Y}",new Date());  outputs: 2015 October
String.format("{0:y}",new Date());  outputs: 2015 October
String.format("{0:yy}",new Date());  outputs: 15
String.format("{0:yyyy}",new Date());  outputs: 2015
String.format("{0:gg}",new Date());  outputs: A.D.
String.format("{0:T}",new Date());  outputs: 20:39:54
String.format("{0:t}",new Date());  outputs: 20:39
String.format("{0:HH}",new Date());  outputs: 20
String.format("{0:mm}",new Date());  outputs: 39
String.format("{0:ss}",new Date());  outputs: 54

It does more then just Dates:

MSDN String.format() Documentation

J5 iJS string format top20 iDate