Load local JSON data in jQgrid without AddJsonRows

I'm using the method addJsonRows to add local data to a jQgrid. As this method disables the sorting I need another solution. One restriction: I can't set the url and fetch the data from the server because the data was passed through another component.

Underneath snippet enlightens the case. The commented line shows the restriction, I replaced it by defining a local variable to have a test case.

<script type="text/javascript" language="javascript">
    function loadPackageGrid() {
    // Get package grid data from hidden input.
    // var data = eval("("+$("#qsmId").find(".qsm-data-packages").first().val()+")");
        var data =  {
            "page": "1",
            "records": "2",
            "rows": [
                { "id": "83123a", "PackageCode": "83123a" },
                { "id": "83566a", "PackageCode": "83566a" }
            ]
        };

        $("#packages")[0].addJSONData(data);
    };

    $(document).ready(function() {
        $("#packages").jqGrid({
            colModel: [
                { name: 'PackageCode', index: 'PackageCode', width: "110" },
                { name: 'Name', index: 'Name', width: "300" }
            ],
            pager: $('#packagePager'),
            datatype: "local",
            rowNum: 10000,
            viewrecords: true,
            caption: "Packages",
            height: 150,
            pgbuttons: false,
            loadonce: true
        });
    });
</script>

I wonder how I could do this in an other (better) way to keep the sorting feature. I tried something with the data option, without result.