FluentDOM\Loader\Json\JsonDOM::onMapKey PHP Method

onMapKey() public method

function callback(string $key, boolean $isArrayElement) }
public onMapKey ( null | FALSE | callable $callback = NULL ) : callable | null
$callback null | FALSE | callable
return callable | null
    public function onMapKey($callback = NULL)
    {
        if (isset($callback)) {
            $this->_onMapKey = is_callable($callback) ? $callback : NULL;
        }
        return $this->_onMapKey;
    }