service-layer.md

Service Layer

Service layer is an architectural pattern, applied within the service-orientation design paradigm, which aims to organize the services, within a service inventory, into a set of logical layers. Services that are categorized into a particular layer share functionality. This helps to reduce the conceptual overhead related to managing the service inventory, as the services belonging to the same layer address a smaller set of activities.

More details: Wiki

Also known as

Façade

Intent

Service Layer is an abstraction over domain logic. It defines application's boundary with a layer of services that establishes a set of available operations and coordinates the application's response in each operation.

Diagram

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Example

Bellow you can see a code snippet of the pattern.

<?php

require_once '../../tests/bootstrap.php';

use Application\Converters\EntityConverter;
use Application\Entities\ProductEntity;
use Application\Services\V1\Product\CreateProductService;
use Application\ValueObjects\ProductValueObject;

$container = new Application\Application(APP_ROOT);

$pencilData = file_get_contents(APP_ROOT . '/samples/common/entities/pencil.product.json');
$pencilVo = new ProductValueObject(json_decode($pencilData, true));

$entityConverter = new EntityConverter(ProductEntity::class);

$createService = new CreateProductService($container);
$createService->setValueObject($pencilVo);
$createService->setConverter($entityConverter);

$entity = null;
$result = false;
if ($createService->validate()) {
    $result = $createService->execute();
    /** @var ProductEntity $entity */
    $entity = $createService->getEntity();
}


if ($result) {
    $id = $entity->id;
    $uuid = $entity->uuid;
    $name = $entity->name;
    $description = $entity->description;
    print("product created: $id $uuid" . PHP_EOL);
    print("product name: $name" . PHP_EOL);
    print("product description: $description" . PHP_EOL);
} else {
    $exception = $createService->getException();
    if ($exception) {
        print($exception->getMessage() . PHP_EOL);
    }
}

php file sample

Obs: You can run it, executing the project clone.

Sample output

Example of output:

product created: 1 fecfddd9-7cb8-413b-9de3-ec86de30a888
product name: Common Pencil
product description: Common Pencil description

Project example

Bellow you can see a code snippet of the pattern.

References

• https://en.wikipedia.org/wiki/Service_layer_pattern
• https://java-design-patterns.com/patterns/service-layer/

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