Revision: Fri, 17 May 2024 13:03:36 GMT

Promise mapper

Cycle ORM provides the ability to carry data over the specific class instances by using cycle/orm-promise-mapper package with \Cycle\ORM\Reference\Promise objects for relations with lazy loading.

Installation

The preferred way to install this package is through Composer:

composer require cycle/orm-promise-mapper

Define the Schema

php
use Cycle\Annotated\Annotation\Entity;
use Cycle\Annotated\Annotation\Relation\HasMany;
use Cycle\ORM\PromiseMapper\PromiseMapper;
use Cycle\ORM\Reference\ReferenceInterface;

#[Entity(mapper: PromiseMapper::class)]
class User
{
    #[Column(type: 'primary')]
    public int $id;

    #[HasMany(target: Post::class, collection: 'array', load: 'eager')]
    public array $posts;
    
    #[HasMany(target: Tag::class, collection: 'array', load: 'lazy')]
    public ReferenceInterface|array $tags;
}

Fetching entity data

php
$user = $orm->getRepository('user')->findByPK(1);

// $user->posts contains an array because of eager loading
foreach ($user->posts as $post) {
    // ...
}

// $user->tags contains Cycle\ORM\Reference\Promise object because of lazy loading
$tags = $user->tags->fetch();
foreach ($tags as $post) {
    // ...
}

$post = $orm->getRepository('post')->findByPK(1);

// $post->user contains Cycle\ORM\Reference\Promise object because of lazy loading
$userId = $post->user->fetch()->id;

// $post->tag contains Tag object because of eager loading
$tagName = $post->tag->name;
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