README

Hermes is a php library to consume Restful APIs using Hal, like Apigility.

It is the main IPC method for other Olympus services.

Can be used with pure PHP or any PHP framework, like ZendFramework 2 and Zend-Expressive.

Requirements

• PHP >= 7.2
• Laminas Http >= 2.4
• Laminas ServiceManager >= 2.5
• nocarrier/hal >= 0.9

You can add the module hermes-loslog to log the requests.

Installation

Using composer (recommended)

php composer.phar require mt-olympus/hermes

Configuration

You need to configure at least the Api URI.

If using a framework that implements container-interopt, you can use the following configuration:

Copy the hermes.global.php.dist from this module to your application's config folder and make the necessary changes.

For more information about the http-client options, please check the official documentation at Laminas\Http\Client options.

'hermes' => [
    'uri' => 'https://localhost:8000',
    'depth' => 0,
    'http_client' => [
        'options' => [
            'timeout'       => 60,
            'sslverifypeer' => false,
            'keepalive'     => true,
            'adapter'       => 'Laminas\Http\Client\Adapter\Socket',
        ],
    ],
    'headers' => [
        'Accept'       => 'application/hal+json',
        'Content-Type' => 'application/json',
    ],
]

Usage

Creating the client

You can use the Hermes\Api\ClientFactory usign the above configuration or manually:

$httpClient = new Laminas\Http\Client('http://127.0.0.1', []);
$client = new Hermes\Apt\Client($httpClient, 10);

Injecting a Cerberus Circuit Breaker

You can use the client with a circuit breaker to control failures and success and avoid uncessary attempts.

More information about cerberus on it's own repository.

$httpClient = new Laminas\Http\Client('http://127.0.0.1', []);
$storage = Laminas\Cache\StorageFactory\StorageFactory::factory([
            'adapter' => [
                'name' => 'memory',
                'options' => [
                    'namespace' => 'my-service',
                ],
            ],
            'plugins' => [
                'exception_handler' => [
                    'throw_exceptions' => false,
                ],
            ],
        ]);
$cerberus = new Cerberus($storage, 2, 2);

// Create a new client
$client = new Hermes\Apt\Client($httpClient, 10, $cerberus, 'my-service');

// Or add it to a previously created client 
$client->setCircuitBreaker($cerberus);
$client->setServiceName('my-service');

Single resource

/* @var \Hermes\Api\Client $client */
$client = $this->getServiceLocator()->get('hermes');
/* @var \Hermes\Resource\Resource $ret */
$ret = $client->get('/album/1');

// $data is an array with all data and resources (_embedded) from the response
$data = $ret->getData();

// $data is an array only with data from the response
$data = $ret->getData(false);

Collection

/* @var \Hermes\Api\Client $client */
$client = $this->getServiceLocator()->get('hermes');

// Setting depth of _embedded resources to 10
$client->setDepth(10);

/* @var \Hermes\Resource\Resource $ret */
$ret = $client->get('/album',['year' => 2015]);

// $data is an array with all data and resources (_embedded) from the response
$data = $ret->getData();

// $data is an array with the first album resource from the response
$data = $ret->getFirstResource('album');

// $data is an array with the all album resources from the response
$data = $ret->getResources('album');

// $data is an array with the all resources from the response
$data = $ret->getResources();

Paginator

This module provides a paginator helper.

/* @var \Hermes\Api\Client $client */
$client = $this->getServiceLocator()->get('hermes');
/* @var \Hermes\Resource\Resource $ret */
$ret = $client->get('/album',['year' => 2015]);

// Returns how many items a page can have
$ret->getPaginator()->getPageSize();

// Returns how many pages the response has
$ret->getPaginator()->getPageCount();

// Returns how many items the response has (across all pages)
$ret->getPaginator()->getTotalItems();

// Returns the current page
$ret->getPaginator()->getPage();

You can easily loop through the pages:

/* @var \Hermes\Api\Client $client */
$client = $this->getServiceLocator()->get('hermes');
$page = 1;
do {
    /* @var \Hermes\Resource\Resource $ret */
    $ret = $client->get('/album',[
        'year' => 2015,
        'page' => $page;
    ]);
    $data = $ret->getData();
    $page++;
} while ($ret->getPaginator()->hasMorePages());

You can use the Paginator with a Zend Framework 2 application:

$page = $this->getRequest()->getQuery('page', 1);
$sort = $this->getRequest()->getQuery('sort', 'name');
$order = $this->getRequest()->getQuery('order', 'asc');

$paginator = new \Laminas\Paginator\Paginator(new \Hermes\Paginator\ApiPaginator($client, $url, 'album', [
    'page'=>$page,
    'sort'=>$sort,
    'order' => $order,
]));
$paginator->setDefaultItemCountPerPage(25);
$paginator->setCurrentPageNumber($page);
$paginator->setPageRange($this->paginatorRange);

Events

The client triggers an event before (request.pre) and after (request.post) a request and you can attach to them. More info about events on zend-eventmanager.

Request Id

The client automatically adds a X-Request-Id to each request, but only if there is no previous X-Request-Id added.

You can force a new id with:

$client = $this->getServiceLocator()->get('hermes');
$client->addRequestId(); // Auto generared
$client->addRequestId('123abc');