public function extraValue($key, $defaultValue = null, $template = false)
    {
        return $this->wrapTemplate($key, $this->context->getExtraValue($key, $defaultValue), $template);
    }
public function extraValue($key, $defaultValue = null, $template = false)
    {
        return $this->wrapTemplate($key, $this->context->getExtraValue($key, $defaultValue), $template);
    }
public function extraValue ( $ key , $ defaultValue = null , $ template = false ) { return $ this -> wrapTemplate ( $ key , $ this -> context -> getExtraValue ( $ key , $ defaultValue ) , $ template ) ; }
Get the value of an extra var.

@param string $key The name of the extra var to return, defined as key inside the `extraVars()` method return array.
@param string $defaultValue Env value is not found this value will be returned.
@param string $template Provde a template which replaces the current variable if value is not `empty()`. e.g. `<p>{{variable}}≤/p>` See {{luya\cms\base\PhpBlockView::wrapTemplate}}.
@return mixed
Get the value of an extra var .