Method getIdentifiers

packages/core/src/entity/Collection.ts:580–607

Returns the primary key values (or a specific field) of all items in the collection.

(field?: string | string[])

  /** Returns the primary key values (or a specific field) of all items in the collection. */
  getIdentifiers<U extends IPrimaryKey = Primary<T> & IPrimaryKey>(field?: string | string[]): U[] {
    const items = this.getItems();
    const targetMeta = this.property.targetMeta!;

    if (items.length === 0) {
      return [];
    }

    field ??= targetMeta.compositePK
      ? targetMeta.primaryKeys
      : (targetMeta.serializedPrimaryKey ?? targetMeta.primaryKeys[0]);

    const cb = (i: T, f: keyof T) => {
      if (Utils.isEntity(i[f], true)) {
        return wrap(i[f], true).getPrimaryKey();
      }

      return i[f] as U;
    };

    return items.map(i => {
      if (Array.isArray(field)) {
        return field.map(f => cb(i, f as keyof T));
      }

      return cb(i, field as keyof T);
    }) as U[];
  }

  /**
   * @internal