<div class="btn btn-primary" id="custom-check-all">Check All</div>
<div class="btn btn-primary" id="custom-invert-all">Invert All</div>


<script>
    $(function(){
        var hot = FormUtil.getField("field1").data("hot");
        $('#custom-check-all').on('click', function(){
            rowcount = hot.countRows();
            for(i = 0; i < rowcount - 1; i++){  // rowcount - 1 to ignore last row
                hot.setDataAtCell(i, 1, true);  // (row, column, value). column is 1 because checkbox is 2nd col in the table
            }
        })
        
        $('#custom-invert-all').on('click', function(){
            rowcount = hot.countRows();
            for(i = 0; i < rowcount - 1; i++){
                if(hot.getDataAtCell(i,1) == true){
                    hot.setDataAtCell(i, 1, false);
                }
                else{
                    hot.setDataAtCell(i, 1, true);
                }
            }
        })
    })
</script>