/**
* Checks to see if any models in the given relation are changed. This function is lazy so will return true as soon
* as it finds something that has changed.
*
* @param Model $obj
* @param string $relation
*
* @return bool
*/
protected function relation_changed(Model $obj, $relation)
{
// Check that the relation exists
if ($obj->relations($relation) === false) {
throw new \InvalidArgumentException('Unknown relation ' . $relation);
}
// If the relation is not loaded then ignore it.
if (!$obj->is_fetched($relation)) {
return false;
}
$relation_object = $obj->relations($relation);
// Check if whe have a singular relation
if ($relation_object->is_singular()) {
// If so check that one model
return $obj->{$relation}->is_changed();
}
// Else we have an array of related objects so start checking them all
foreach ($obj->{$relation} as $related_model) {
if ($related_model->is_changed()) {
return true;
}
}
return false;
}
