https://community.progress.com/community_groups/mobile/f/17/p/21774/76386#76386

        var baseDS = {
           type: "jsdo",
           serverFiltering: true,
           //batch:true,
           transport: {
               jsdo: "Demo.CustomerBusinessEntity",
               tableRef: "eCustomer",
               countFnName: "count"
           },
           schema: {
               model: {
                   fields: {
                       // We need to be able to extend schema e.g. set validation
                       CustRef: {
                           type: "string",
                           editable: false,
                           validation: { required: true },
                       }
                   }
               }
           },