$related * @param non-empty-list>|non-empty-list, 1: string}>|class-string<\Illuminate\Database\Eloquent\Model> $through * @param string|null $localKey * @param string $prefix * @param array, string> $foreignKeyLookup * @param array, string> $localKeyLookup * @return \Znck\Eloquent\Relations\BelongsToThrough */ public function belongsToThrough( $related, $through, $localKey = null, $prefix = '', $foreignKeyLookup = [], array $localKeyLookup = [] ) { /** @var TRelatedModel $relatedInstance */ $relatedInstance = $this->newRelatedInstance($related); /** @var list<\Illuminate\Database\Eloquent\Model> $throughParents */ $throughParents = []; $foreignKeys = []; foreach ((array) $through as $model) { $foreignKey = null; if (is_array($model)) { /** @var string $foreignKey */ $foreignKey = $model[1]; /** @var class-string<\Illuminate\Database\Eloquent\Model> $model */ $model = $model[0]; } $instance = $this->belongsToThroughParentInstance($model); if ($foreignKey) { $foreignKeys[$instance->getTable()] = $foreignKey; } $throughParents[] = $instance; } $foreignKeys = array_merge($foreignKeys, $this->mapKeys($foreignKeyLookup)); $localKeys = $this->mapKeys($localKeyLookup); return $this->newBelongsToThrough( $relatedInstance->newQuery(), $this, $throughParents, $localKey, $prefix, $foreignKeys, $localKeys ); } /** * Map keys to an associative array where the key is the table name and the value is the key from the lookup. * * @param array, string> $keyLookup * @return array */ protected function mapKeys(array $keyLookup): array { $keys = []; // Iterate over each model and key in the key lookup foreach ($keyLookup as $model => $key) { // Create a new instance of the model $instance = new $model(); // Add the table name and key to the keys array $keys[$instance->getTable()] = $key; } return $keys; } /** * Create a through parent instance for a belongs-to-through relationship. * * @template TModel of \Illuminate\Database\Eloquent\Model * * @param class-string $model * @return TModel */ protected function belongsToThroughParentInstance($model) { /** @var array{0: class-string, 1?: string} $segments */ $segments = preg_split('/\s+as\s+/i', $model); /** @var TModel $instance */ $instance = new $segments[0](); if (isset($segments[1])) { $instance->setTable($instance->getTable() . ' as ' . $segments[1]); } return $instance; } /** * Instantiate a new BelongsToThrough relationship. * * @template TRelatedModel of \Illuminate\Database\Eloquent\Model * @template TDeclaringModel of \Illuminate\Database\Eloquent\Model * * @param \Illuminate\Database\Eloquent\Builder $query * @param TDeclaringModel $parent * @param non-empty-list<\Illuminate\Database\Eloquent\Model> $throughParents * @param string|null $localKey * @param string $prefix * @param array $foreignKeyLookup * @param array $localKeyLookup * @return \Znck\Eloquent\Relations\BelongsToThrough */ protected function newBelongsToThrough( Builder $query, Model $parent, array $throughParents, $localKey, $prefix, array $foreignKeyLookup, array $localKeyLookup ) { return new Relation($query, $parent, $throughParents, $localKey, $prefix, $foreignKeyLookup, $localKeyLookup); } }