beforeBlockHandleApply
pro version only
This functionality requires PRO version of the DHTMLX Grid (or DHTMLX Suite) package.
triggered before applying the handle action
Usage
beforeBlockHandleApply: (
    startCell: { row: object; column: object },
    endCell: { row: object; column: object },
    dragDirection: "up" | "down" | "left" | "right" | null,
    event: MouseEvent | TouchEvent
) => boolean | void;
Parameters:
The callback of the event is called with the following parameters:
| startCell | (object) an object that contains the initial cell of the selection, includes the following properties:
  | 
| endCell | (object) an object that contains the end cell of the selection, includes the following properties:
  | 
| dragDirection | (string) determines the direction of movement of the focused cell: "up" | "down" | "left" | "right" | null | 
| event | (Event) the browser event: MouseEvent or TouchEvent | 
Returns:
Return false to cancel the action; otherwise, true.
Example
grid.block.events.on("beforeBlockHandleApply", (startCell, endCell, dir) => {
    if (dir === "right" | dir === "left") {
        console.log("Horizontal change canceled");
        return false;
    }
});
Related API: afterBlockHandleApply
Change log:
added in v9.2