src/Forms/TreeDropdownField.php
public function setSearchFunction($callback)
    {
        if (!is_callable($callback, true)) {
            throw new InvalidArgumentException('TreeDropdownField->setSearchFunction(): not passed a valid callback');
        }

        $this->searchCallback = $callback;
        return $this;
    }
public function setSearchFunction($callback)
    {
        if (!is_callable($callback, true)) {
            throw new InvalidArgumentException('TreeDropdownField->setSearchFunction(): not passed a valid callback');
        }

        $this->searchCallback = $callback;
        return $this;
    }
public function setSearchFunction ( $ callback ) { if ( ! is_callable ( $ callback , true ) ) { throw new InvalidArgumentException ( 'TreeDropdownField->setSearchFunction(): not passed a valid callback' ) ; } $ this -> searchCallback = $ callback ; return $ this ; }
Set a callback used to search the hierarchy globally, even before
applying the filter.

@param callable $callback
@return $this
Set a callback used to search the hierarchy globally even before applying the filter .