WakeOnWeb Swagger Validation Component

The WakeOnWeb Swagger Validation Component is an extensible component for validating API data using the Swagger - OpenAPI specification. The component supports both YAML and JSON Open API file formats. The component has very a small dependency set in order to be usable in different PHP frameworks.

The component uses:

• PSR-6: For caching your OpenApi specification files
• PSR-7: For processing HTTP messages (requests and responses)

Installation

The component can easily be installed using

composer require wakeonweb/swagger

The component uses a JSON Schema validator, by default, the justinrainbow/json-schema is in the dev dependencies. If you intend to use the component in production you need to execute:

composer require justinrainbow/json-schema

Loading an OpenAPI specification file

The component supports both YAML and JSON OpenAPI format. Swagger files are loaded by the SwaggerFactory. The factory accepts a PSR-6 CacheItemPoolInterface. If none provided it will use the ArrayCachePool provided by cache/array-adapter.

$factory = new SwaggerFactory();

// Register a YAML loader to load YAML Swagger files.
$factory->addLoader(new YamlLoader());

// Load the Swagger definition.
$swagger = $factory->buildFrom('/path/to/swagger/file.yml');

Executing this code will result in retrieving a tree representation of the specification into an instance of a Swagger document. At the moment, the cache contains the instance of the Swagger document.

Creating the a content validator

Content validation in the component is based on JSON Schema Validation. The OpenAPI Specification handles much more than this. For example it allows to define query string parameters or the format of any HTTP Headers. The component supports all kind of validation.

Content validators are used to validate the content of a request or a response. Any content validator must implement the ContentValidatorInterface and should be registered into an instance of a ContentValidator. The resulting instance can be used into an instance of a SwaggerValidator.

// Create a content validator that validates requests and responses bodies.
$contentValidator = new ContentValidator();

// Register a specific content validator that handle "application/json".
$contentValidator->registerContentValidator(new JustinRainbowJsonSchemaValidator());

Validating a response

Validating response makes sense only for testing... As you are supposed to have valid code respectful of your interface agreements in production!

// Create the validator and register the content validator.
$validator = new SwaggerValidator($swagger);
$validator->registerResponseValidator($contentValidator);

// Sample with Symfony Response....
$response = new Response(...);

$psr7Factory = new DiactorosFactory();

// Converts the response to a PSR-7 compliant format.
$response = $psr7Factory->createResponse($response);

try {
    // Validates the response against the required specification.
    $validator->validateResponseFor($response, PathItem::METHOD_GET, '/api/resource', 200);
} catch (SwaggerValidatorException $e) {
    // display $e message.
}

Validating a request

Validating response makes sense only for testing... As you are supposed to have valid code respectful of your interface agreements in production!

// Create the validator and register the content validator.
$validator = new SwaggerValidator($swagger);
$validator->registerRequestValidator($contentValidator);

// Sample with Symfony Response....
$request = new Request(...);

$psr7Factory = new DiactorosFactory();

// Converts the response to a PRS-7 compliant format.
$request = $psr7Factory->createRequest($request);

try {
    // Validates the request against the required specification.
    $validator->validateRequestFor($request, PathItem::METHOD_GET, '/api/resource');
} catch (SwaggerValidatorException $e) {
    // display $e message.
}

Complete sample

The following sample code demonstrates a complete usage of the component.

<?php

use Symfony\Bridge\PsrHttpMessage\Factory\DiactorosFactory;
use Symfony\Component\HttpFoundation\Response;
use WakeOnWeb\Component\Swagger\Specification\PathItem;
use WakeOnWeb\Component\Swagger\SwaggerFactory;
use WakeOnWeb\Component\Swagger\Loader\YamlLoader;
use WakeOnWeb\Component\Swagger\Loader\JsonLoader;
use WakeOnWeb\Component\Swagger\Test\ContentValidator;
use WakeOnWeb\Component\Swagger\Test\Exception\SwaggerValidatorException;
use WakeOnWeb\Component\Swagger\Test\JustinRainbowJsonSchemaValidator;
use WakeOnWeb\Component\Swagger\Test\SwaggerValidator;

$factory = new SwaggerFactory();

// Register a YAML loader to load YAML Swagger files.
$factory->addLoader(new YamlLoader());

// Load the Swagger definition.
$swagger = $factory->buildFrom('/path/to/swagger/file.yml');

// Create a content validator that validates requests and responses bodies.
$contentValidator = new ContentValidator();

// Register a specific content validator that handle "application/json".
$contentValidator->registerContentValidator(new JustinRainbowJsonSchemaValidator());

// Create the validator and register the content validator.
$validator = new SwaggerValidator($swagger);
$validator->registerResponseValidator($contentValidator);

$response = new Response(
    '{...}',
    200,
    [
        'Content-Type' => 'application/json',
    ]
);

$psr7Factory = new DiactorosFactory();

// Converts the response to a PRS-7 compliant format.
$response = $psr7Factory->createResponse($response);

try {
    // Validates the response against the required specification.
    $validator->validateResponseFor($response, PathItem::METHOD_GET, '/api/resource', 200);
} catch (SwaggerValidatorException $e) {
    // display $e message.
}