With this you can set a function to groupText parameter when you define your grid.

I'd like if this patch can be put in next version of jqgrid 🙂

Example:

[.......]

        grouping:true,
        groupingView : {

            groupField : ['groupId'],

            groupColumnShow : [false],

            groupText : function(group) { return myCustomGroupdata[group].someStringAttr+" - Total  {1}"; }

},

[.......]

Patch code at line 10381 of jqGrid 4.2.0 :

                try {
                    _groupText = jQuery.isFunction(grp.groupText)? grp.groupText(gv) : grp.groupText[0];
                    groupText = (typeof _groupText).toLowerCase() != "string" ||  _groupText == "" ? "{0}" : _groupText;
                } catch(egt) {
                    groupText = "{0}";
                }
                
                str += "<tr id=""+hid+"" role="row" class= "ui-widget-content jqgroup ui-row-"+$t.p.direction+""><td colspan=""+colspans+"">"+icon+$.jgrid.format(groupText, gv, grdata[n].length)+"</td></tr>";