/**
* Extract a configuration subset
*
* This will return a new Config object, only containing values whose identifiers match
* the given filter.
*
* @note Identifiers in the subset are cleaned up so that the filter part is removed.
* This is one of the reasons why the '.*' pattern is automatically added to the filter.
* This behaviour does not actually prevent from passing a full Matcher compatible pattern,
* but discourages it.
*
* @param $filter
*
* @return Config
*/
public function subset($filter)
{
$filterLength = strlen($filter) + 1;
// + 1 for the '.' following the prefix
// normalize filter
$filter .= '.*';
$subset = new Config();
foreach ($this as $key => $value) {
if ($this->getMatcher()->match($filter, $key)) {
$subset->set(substr($key, $filterLength), $value);
}
}
return $subset;
}
public function testDirectiveGroupFetchingUsingMatcher()
{
$config = new Config();
$config->set('x.y', 'a')->set('x.z', 'b');
$this->assertEquals(['y' => 'a', 'z' => 'b'], $config->subset('x')->toArray());
}
