README

Object Metadata is a package to help developer manage custom global object metadata. This package use WeakMap to control the data mapping with object instances.

Installation

composer require asika/object-metadata

Getting Started

Basic usage:

use Asika\ObjectMetadata\ObjectMetadata; // Create any objects $obj = new ArticleEntity(); // Get global main instance $meta = ObjectMetadata::getInstance(); // Set custom metadata $meta->set($obj, 'foo', 'Hello'); // Now you can get the data everywhere if this object still exists and not destruct yet ObjectMetadata::getInstance()->get($obj, 'foo'); // Hello // Available methods $meta->get($obj, 'key'); $meta->set($obj, 'key', 'value'); $meta->has($obj, 'key'); $meta->remove($obj, 'key'); $meta->getMetadata($obj, 'key'); // array $meta->setMetadata($obj, 'key', $data);

Use wrapper:

$obj = new ArticleEntity(); $meta = ObjectMetadata::getInstance(); $metaWrapper = $meta->wrapper($obj); $metaWrapper->set('foo', 'Hello'); $metaWrapper->get('key'); $metaWrapper->has('key'); $metaWrapper->remove('key'); $metaWrapper->all(); // Array Access $metaWrapper['key'] = 'value'; // If object destructed, getting metadata will be NULL unset($obj); $metaWrapper->get('foo'); // NULL

Scope

The ObjectMetadata is able to separate different scopes.

$meta = ObjectMetadata::getInstance('main'); // Main scope $appMeta = ObjectMetadata::getInstance('app'); $dbMeta = ObjectMetadata::getInstance('db');

What is The Real Usage

The useful case for this package is that we can make some entity object or value object to be a rich object. for example, if a ORM uses data-mapper pattern, their entity object will be a anemic object which may not keep the ORM instance.

$item = new Article(); $item = $orm->createOne($item); // This item will only contains pure data

If the ORM use this package to make themselves as entity metadata, we can make the Article entity as a rich object and has the capacity to all ORM to get another objects.

$orm->on('entity.prepare', function (object $entity, ORM $orm) { ObjectMetadata::getInstance('db')->set($entity, 'orm', $orm); }); class Article { // ... // Article can use ObjectMetadata to get ORM instance. public function getComments() { $orm = ObjectMetadata::getInstance('db')->get($this, 'orm'); return $orm->from(Comment::class) ->where('article_id', $this->getId()) ->all(); } } // Now we can test it $article = $orm->createEntity(Article::class); $item = $orm->createOne($item); // Article is able to call ORM to get another items from DB $item->getComments(); $item->getAuthor(); $item->getTags();