Ext.override(Ext.ux.data.PagingMemoryProxy,{
    doRequest: function(action, rs, params, reader, callback, scope, options){
        params = params ||
        {};
        var result;
        try {
            result = reader.readRecords(this.data);
        }
        catch (e) {
            this.fireEvent('loadexception', this, options, null, e);
            callback.call(scope, null, options, false);
            return;
        }

        // filtering
        if (params.filter !== undefined) {
            result.records = result.records.filter(function(el){
                if (typeof(el) == 'object') {
                    var att = params.filterCol || 0;
                    return String(el.data[att]).match(params.filter) ? true : false;
                }
                else {
                    return String(el).match(params.filter) ? true : false;
                }
            });
            result.totalRecords = result.records.length;
        }

        // sorting
        if (params.sort !== undefined) {
            // use integer as params.sort to specify column, since arrays are not named
            // params.sort=0; would also match a array without columns
            var dir = String(params.dir).toUpperCase() == 'DESC' ? -1 : 1;
            var fn = function(r1, r2){
				return r1 == r2 ? 0 : r1 < r2 ? -1 : 1;
            };
            result.records.sort(function(a, b){
                var v = 0;
                if (typeof(a) == 'object') {
                    v = fn(a.data[params.sort], b.data[params.sort]) * dir;
                }
                else {
                    v = fn(a, b) * dir;
                }
                if (v == 0) {
                    v = (a.index < b.index ? -1 : 1);
                }
                return v;
            });
        }

        // paging (use undefined cause start can also be 0 (thus false))
        if (params.start !== undefined && params.limit !== undefined) {
            result.records = result.records.slice(params.start, params.start + params.limit);
        }
        callback.call(scope, result, options, true);
	}
});