/**
* Registers a JS file.
* @param string $url the JS file to be registered.
* @param array $options the HTML attributes for the script tag. A special option
* named "position" is supported which specifies where the JS script tag should be inserted
* in a page. The possible values of "position" are:
*
* - `POS_HEAD`: in the head section
* - `POS_BEGIN`: at the beginning of the body section
* - `POS_END`: at the end of the body section. This is the default value.
*
* @param string $key the key that identifies the JS script file. If null, it will use
* $url as the key. If two JS files are registered with the same key, the latter
* will overwrite the former.
*/
public function registerJsFile($url, $options = [], $key = null)
{
$key = $key ?: $url;
if (is_array($key)) {
$key = current($key);
}
$position = isset($options['position']) ? $options['position'] : self::POS_END;
unset($options['position']);
$this->jsFiles[$position][$key] = $this->renderWrapperTag(Html::jsFile($url, $options), $options);
}
