DeleteProjectSites.js

var script = document.createElement('script');script.src = "https://ajax.googleapis.com/ajax/libs/jquery/2.2.0/jquery.min.js";document.getElementsByTagName('head')[0].appendChild(script);

function retrieveData(url) {
    var dfd = jQuery.Deferred();

    console.log('Data url is + ' + url)
    jQuery.ajax({url:url,
    type: "GET",
    dataType: "json",
    headers: {Accept: "application/json;odata=verbose"	}       
   , success: function (data, textStatus, XmlHttpRequest) {
                if (null != data.d.__next) {
                      retrieveData(data.d.__next).done(function (results) {
                          dfd.resolve(results.concat(data.d.results));
                      });
                }
                else {
                    dfd.resolve( data.d.results );
                }
        },
        error: function (XmlHttpRequest, textStatus, errorThrown) { alert('Unable to retrieve data:' + textStatus); }
    });
    return dfd.promise();
}


function DeleteSites() {

    var url = _spPageContextInfo.siteAbsoluteUrl + "/_api/ProjectData/[en-US]/Projects()?"
    + "$filter=ProjectWorkspaceInternalUrl%20ne%20null"
    + "&$select=ProjectId,ProjectName,ProjectWorkspaceInternalUrl"
    + "&$orderby=ProjectName";

    retrieveData(url).done (function (projects) {
        console.log ("Retreived projects count " + projects.length);
        for (var i = 0; i < projects.length; i++) {
            var projectId = projects[i].ProjectId;
            var projectName = projects[i].ProjectName;
            console.log ("Deleting Project Site for Project: " + projectName);
            $get('idOperation').value = "DeleteWeb";
            $get('idProjectUID').value = projectId;
            $get('idProjectName').value = projectName;
            DoCallback();
        }

    });
};

function PJ_ServerCallback_Complete(retString, context)
{
    var oReturnData = new PJServerCallBackReturnData(retString);
	console.log("Return Message = " + oReturnData.Message);

}