Tuesday, September 8, 2015

How to call SharePoint REST Web Services from SharePoint Designer 2013 and Fiddler?

What?

SharePoint 2013 introduced a new action in SharePoint Designer 2013 workflows to call a http web service called "Call HTTP Web Service".

There are thousand other blog posts explaining how to use that action but in this post I am going to focus on and detail how to use GET and POST http methods with REST based native SharePoint 2013 web services.

Why?

SharePoint 2013 (and previous versions) uses a client side “token” to validate posts back to SharePoint to prevent attacks where the user might be tricked into posting data back to the server. This token is known by many names; form digest ormessage digest or request digest. The token is unique to a user and a site and is only valid for a (configurable) limited time.

Calling a SharePoint 2013 REST POST http method therefore requires adding the Request Digest token to the request header of the request as the “X-RequestDigest” header.

How?

The first step to test out the queries is to use CAML Designer 2013 and Fiddler.