SP2013: Getting a Form Digest for Update REST calls

While on SharePoint 2013 training we came across all the different ways of calling SharePoint and it’s data through JavaScript, JQuery and all the bits. It was all looking good until we needed to update sharepoint – e.g. a list, a list item etc. The MS Course notes say – “if you’re in SharePoint you can get the Form Digest from the main SharePoint Form….” What about if you’re running outside of SharePoint (a Provider App – they now call it, or Cloud Hosted…depending on who wrote the help article...(read more)Image may be NSFW.
Clik here to view.