jQuery Grid Plugin - jqGrid

I was thinking through the same problem last week and i solved it like this. Start out with your datatype set to a function, that loads your initial data via "$table[0].addJSONData(initialResults)", and then make that same function overwrite the datatype property [itself].

var url = "/researchCatalog/Search/ProviderGridData/";
var gridData = getGridData(url, searchParams)
var colModel = gridData.colModel;
var initialResults = gridData.initialResults;
var datatype = function() {
            //there's a little bit of trickery going on in this function
            //so that we can create a jqGrid with initial results,
            //and also hook into all of the auto AJAXy stuff built into the grid
            //when initially creating the grid we use a function as the datatype,
            //but in the function we reset the grids datatype to json
            $table[0].addJSONData(initialResults)
            //reset the datatype variable to json so it will make calls on its own
            $table.setGridParam({ datatype: "json" });

}

        $table.jqGrid({
            url: url,
            datatype: datatype,
            colModel: colModel,
            pagerpos: 'left',
            pager: $("#" + pagerID),
            pgbuttons: true,
            gridComplete: function() {
                RSCat.ContentManager.resizeGrid($table);
            },
        });