tag.php
public function setValue($value)
    {
        for ($i = 0, $count = count($this->options); $i < $count; $i++) {
            if ($this->options[$i]->isValue($value)) {
                $this->choice = $i;

                return true;
            }
        }

        return false;
    }
public function setValue($value)
    {
        for ($i = 0, $count = count($this->options); $i < $count; $i++) {
            if ($this->options[$i]->isValue($value)) {
                $this->choice = $i;

                return true;
            }
        }

        return false;
    }
Can only set allowed values.

@param string $value       New choice.

@return bool            True if allowed.