How can I set “IsSiteAdmin” property true for a user via Webservice/REST API for Sharepoint?

Question

The question actually is that whether or not an Admin (Company Administrator) assign a user(say himself) who is NOT a site user on a Site as Site Collection Admin for the OneDrive(my site) for other tenant users.

Let's say that admin is abc@[email protected] and there is a user say pqr@[email protected]. The OneDrive(my site) for this user would be;

https://mytenant-my.sharepoint.com/personal/prq_onmicrosoft_com

Can I make [email protected] (who is NOT a site user on pqr@[email protected]) a Site Collection Administrator on this site?

Much appreciated!

NOTE: Currently, I am doing it via Powershell but I'm interested in doing it via APIs.

Answer 1

Here is an example of how to do it using CSOM: http://blogs.msdn.com/b/mimorr/archive/2014/01/22/adding-site-collection-admin-in-csom-in-a-sharepoint-2013-app.aspx

If you setup this example, and then run Fiddler to see how the CSOM code gets translated into REST calls, you should be able to get the REST call you need.