Returns the filter expression of a specific column. If no filter is set, a null is returned.
Parameter:
- columnIndex - index to identify the column, where 0 is the first column, 1 is the second column, etc.
Example:
var expression = getObj("Grid1").grid.getFilter(0);
if (expression == null) {
alert("The first column in the grid has no filter.")
}
else {
alert("The following filter is applied to the first column: " + expression);
}