Master Checkbox: Automatically Update

I’ve noticed a slightly annoying issue with the master checkbox option in the headers for the dhtmlxGrid. When all the checkboxes in the below column are manually checked, the master checkbox does not become checked. This is illustrated in the yellow column below:

How can I make the master checkbox automatically update based on the selections made below? I want to make this master checkbox’s select all/deselect all mechanism emulate typical experiences, but see no way to do it within the API provided for the dhtmlxGrid product.

Thank you.

Unfortunately such feature is not available.
You may change the inner code to make the master checkbox checked initially.
open “dhtmlxgrid_filter.js”, find the string:

t.innerHTML=c[0]+"<input type='checkbox' />"+c[1];

and replace it with:

t.innerHTML=c[0]+"<input type='checkbox' checked='true'/>"+c[1];