chargemap/ocpi-protocol

Library to handle OCPI. Compatible with PSRs. Uses JsonSchema to validate payloads.

0.3.1 2020-08-26 14:26 UTC

This package is auto-updated.

Last update: 2021-09-26 17:04:40 UTC


README

Library to handle OCPI. Compatible with PSRs.

Functionality

Library provides OCPI request/response classes for eMSP interfaces, models, factories and errors. Listing requests/responses are also supported for GET routes. The responses need a corresponding request to be constructed. It is required to ensure the presence and validity of offset and limit request headers and X-Total-Count, X-Limit and Link response headers. So it is quite easy to construct valid listing response or get the next request.

eMSP interface

Respond to CPO

use Chargemap\OCPI\Versions\V2_1_1\Server\Emsp\Sessions\Put\OcpiEmspSessionPutRequest;
use Chargemap\OCPI\Versions\V2_1_1\Server\Emsp\Sessions\Put\OcpiEmspSessionPutResponse;
use Psr\Http\Message\RequestInterface;
use Psr\Http\Message\ResponseInterface;

/** @var RequestInterface $httpRequest */
$sessionPutRequest = new OcpiEmspSessionPutRequest($httpRequest, 'NL', 'TNM', '101');
$session = $sessionPutRequest->getSession();

// Some code...

$sessionPutResponse = new OcpiEmspSessionPutResponse($session);
/** @var ResponseInterface $response */
$response = $sessionPutResponse->getResponseInterface();

Each request and response class correspond to an eMSP interface route. Request classes must be instantiated by providing PSR-7 compatible request (got from CPO). Internally, it extracts the authorization token from headers, and validates the body (if necessary) against json schema. Then, it constructs corresponding model class using the factories. The model is accessible via a getter.

Response classes must be instantiated with a model instance, even if it's not used (e.g. in Post/Put/Patch responses). It can be converted to PSR-7 compatible response instance using getResponseInterface method.

Use of listing request/response

use Chargemap\OCPI\Versions\V2_1_1\Server\Emsp\Tokens\Get\OcpiEmspTokenGetRequest;
use Chargemap\OCPI\Versions\V2_1_1\Server\Emsp\Tokens\Get\OcpiEmspTokenGetResponse;
use Psr\Http\Message\RequestInterface;
use Psr\Http\Message\ResponseInterface;

/** @var RequestInterface $httpRequest */
$tokenGetRequest = new OcpiEmspTokenGetRequest($httpRequest);
$tokens = [];
$tokenCount = 0;

//Fetch tokens from database...

$tokenGetResponse = new OcpiEmspTokenGetResponse($tokenGetRequest, $tokenCount, count($tokens));
foreach ($tokens as $token) {
    $tokenGetResponse->addToken($token);
}
// X-Total-Count, X-Limit and Link headers are already set in $response
/** @var ResponseInterface $response */
$response = $tokenGetResponse->getResponseInterface();

Request the CPO

This part provides an API SDK to request the CPO. To use it, you need to instantiate the OcpiClient with OcpiConfiguration and needed endpoints. Then you can perform the requests like that:

use Chargemap\OCPI\Versions\V2_1_1\Client\Locations\GetListing\GetLocationsListingRequest;
use Chargemap\OCPI\Versions\V2_1_1\Common\Models\Location;
use Chargemap\OCPI\Common\Client\OcpiClient;
use Chargemap\OCPI\Common\Client\OcpiConfiguration;
use Chargemap\OCPI\Common\Client\OcpiEndpoint;
use Chargemap\OCPI\Common\Client\OcpiVersion;
use Chargemap\OCPI\Common\Client\OcpiModule;

$ocpiClient = new OcpiClient(
            (new OcpiConfiguration($supervisorAuthString))
                ->withEndpoint(new OcpiEndpoint(
                    OcpiVersion::V2_1_1(),
                    OcpiModule::LOCATIONS(),
                    new Uri('ocpi/cpo2.0/locations'))
                )
        );
$getLocationListingRequest = (new GetLocationsListingRequest())
                                ->withOffset(0)
                                ->withLimit(100)
                                ->withDateFrom($dateFrom)
                                ->withDateTo($dateTo);
$locationResponse = $ocpiClient->V2_1_1()->locations()->getListing($getLocationListingRequest);
/** @var Location[] $locations */
$locations = $locationResponse->getLocations();
//Some code...

Listing request/response

use Chargemap\OCPI\Versions\V2_1_1\Client\Locations\GetListing\GetLocationsListingRequest;
use Chargemap\OCPI\Common\Client\OcpiClient;
use Chargemap\OCPI\Common\Client\OcpiConfiguration;
use Chargemap\OCPI\Common\Client\OcpiEndpoint;
use Chargemap\OCPI\Common\Client\OcpiVersion;
use Chargemap\OCPI\Common\Client\OcpiModule;

$ocpiClient = new OcpiClient(
            (new OcpiConfiguration($supervisorAuth))
                ->withEndpoint(new OcpiEndpoint(
                    OcpiVersion::V2_1_1(),
                    OcpiModule::LOCATIONS(),
                    new Uri('ocpi/cpo2.0/locations'))
                )
        );
$getLocationListingRequest = (new GetLocationsListingRequest())
                                ->withOffset(0)
                                ->withLimit(100)
                                ->withDateFrom($dateFrom)
                                ->withDateTo($dateTo);
do {
    $locationResponse = $this->ocpiClient->V2_1_1()->locations()->getListing($getLocationListingRequest);
    
    //Some code...     
    
    //Next request will update its limit and offset values
    $getLocationListingRequest = $locationResponse->getNextRequest();
} while ($getLocationListingRequest !== null);

Common

Errors

Each error class corresponds to an OCPI error code. It can be converted to the PSR-7 response instance just like any response class. It ensures correct HTTP error code as well as OCPI status code.

use Chargemap\OCPI\Common\Server\Errors\OcpiGenericClientError;
use Psr\Http\Message\ResponseInterface;

$error = new OcpiGenericClientError('Client error');
//Correct payload and HTTP error code is already set
/** @var ResponseInterface $response */
$response = $error->getResponseInterface();

Errors are supposed to be thrown and caught by a middleware/listener and then transformed to the response.

Models

Models fetched from request's/response's json body correspond to the OCPI objects. The exception to the rule is Partial[Class] classes, that are used in PATCH routes. They have the same but nullable properties as their corresponding [Class].