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beforeExpand

fires before expanding a tree item

beforeExpand: (id: string | number) => boolean | void;

Parameters:

  • id: string | number - the id of an expanded item

Returns:

Return false to block expanding a tree item; otherwise, true.

Example

tree.events.on("beforeExpand", function(id) {
    // your logic here
    return false;
});

Related sample: Tree. Events

Change log:

added in v6.4