/**
* Get related objects from the database
*
* Supports the following signatures:
*
* - getRelated( object|array $source , string $relationName )
* - getRelated( object|array $source , string $relationName , $query )
* - getRelated( object|array $source , string $relationName , Meta $meta )
* - getRelated( object|array $source , string $relationName , $query, Meta $meta )
*
* @return object[]
*/
public function getRelated($source, $relationName, $query = null, $meta = null)
{
if (!$source) {
return;
}
$sourceIsArray = false;
$test = $source;
if (is_array($test) || $test instanceof \Traversable) {
$sourceIsArray = true;
$test = $test[0];
}
if (!$meta) {
if ($query instanceof Meta) {
list($meta, $query) = [$query, null];
} else {
$meta = $this->mapper->getMeta(get_class($test));
}
} else {
$meta = $meta instanceof Meta ? $meta : $this->mapper->getMeta($meta);
}
if (!isset($meta->relations[$relationName])) {
throw new Exception("Unknown relation {$relationName} on {$meta->class}");
}
$relation = $meta->relations[$relationName];
$relator = $this->getRelator($relation);
if ($query) {
// need to support both Query\Criteria and Query\Select
// this is a cheeky hack - the API doesn't declare support for
// Select in Relators because it carries promises of things like
// 'fields' and whatnot that we'll never be able to satisfy.
// That whole hierarchy needs to be cleaned
// up into a bunch of traits so we can have RelatorCriteria or something.
$query = $query instanceof Query\Criteria ? $query : Query\Select::fromParamArgs([$query]);
$stack = $query->stack;
} else {
$stack = [];
}
$stack[$meta->class] = true;
if ($sourceIsArray) {
return $relator->getRelatedForList($meta, $source, $relation, $query ?: null, $stack);
} else {
return $relator->getRelated($meta, $source, $relation, $query ?: null, $stack);
}
}
