What are the differences between Guzzle 6 and Guzzle 7?

Guzzle 7 represents a significant evolution of the popular PHP HTTP client library, introducing modern PHP features and improved standards compliance. This guide outlines the key differences between Guzzle 6 and 7 to help you understand the upgrade path.

Major Changes Overview

1. PHP Version Requirements

  • Guzzle 6: PHP >= 5.5 (works with 5.4 with limitations)
  • Guzzle 7: PHP >= 7.2.5 (leverages modern PHP features)

This change allows Guzzle 7 to utilize PHP 7's performance improvements and modern language features.

2. Type Declarations and Return Types

Guzzle 7 embraces PHP 7's type system for better code reliability:

Guzzle 6 (no type hints):

public function request($method, $uri, array $options = [])
{
    return $this->requestAsync($method, $uri, $options)->wait();
}

Guzzle 7 (with type hints):

public function request(string $method, $uri, array $options = []): ResponseInterface
{
    return $this->requestAsync($method, $uri, $options)->wait();
}

3. Enhanced Exception Handling

Guzzle 7 introduces more specific exception classes for better error handling:

use GuzzleHttp\Exception\ClientException;
use GuzzleHttp\Exception\ServerException;

try {
    $response = $client->get('https://api.example.com/users');
} catch (ClientException $e) {
    // Handle 4xx client errors (400-499)
    echo "Client error: " . $e->getResponse()->getStatusCode();
} catch (ServerException $e) {
    // Handle 5xx server errors (500-599)
    echo "Server error: " . $e->getResponse()->getStatusCode();
}

4. PSR-18 HTTP Client Compliance

Guzzle 7 fully implements PSR-18, making it interchangeable with other PSR-18 compliant HTTP clients:

use Psr\Http\Client\ClientInterface;
use Psr\Http\Message\RequestFactoryInterface;

class ApiClient
{
    private ClientInterface $httpClient;
    private RequestFactoryInterface $requestFactory;

    public function __construct(ClientInterface $client, RequestFactoryInterface $factory)
    {
        $this->httpClient = $client;
        $this->requestFactory = $factory;
    }
}

5. Improved Promises/A+ Compliance

Guzzle 7 provides better promise handling with full Promises/A+ specification compliance:

// Async requests with improved promise handling
$promises = [
    'users' => $client->getAsync('https://api.example.com/users'),
    'posts' => $client->getAsync('https://api.example.com/posts'),
];

$responses = \GuzzleHttp\Promise\settle($promises)->wait();

foreach ($responses as $key => $response) {
    if ($response['state'] === 'fulfilled') {
        echo "{$key}: " . $response['value']->getStatusCode() . "\n";
    }
}

6. Enhanced cURL Multi-Handling

Guzzle 7 uses more efficient cURL functions for concurrent requests:

  • Guzzle 6: Uses curl_multi_exec() only
  • Guzzle 7: Supports curl_multi_poll() and curl_multi_wait() for better performance

This results in improved performance for concurrent HTTP requests.

7. Improved Base URI Handling

Guzzle 7 provides better URI resolution when combining base URIs with relative paths:

$client = new Client(['base_uri' => 'https://api.example.com/v1/']);

// Both versions work, but Guzzle 7 handles edge cases better
$response = $client->get('users/123');  // Resolves to: https://api.example.com/v1/users/123
$response = $client->get('/users/123'); // Resolves to: https://api.example.com/users/123

8. Enhanced Debugging Capabilities

Guzzle 7 offers improved debugging with better request/response logging:

use GuzzleHttp\Middleware;

$stack = HandlerStack::create();
$stack->push(Middleware::log(
    $logger,
    new MessageFormatter('{method} {uri} HTTP/{version} {req_body}')
));

$client = new Client(['handler' => $stack]);

9. Improved Streaming Support

Enhanced streaming capabilities with more customization options:

$client = new Client();
$response = $client->get('https://example.com/large-file.zip', [
    'stream' => true,
    'sink' => fopen('/path/to/local/file.zip', 'w')
]);

Migration Considerations

Breaking Changes

When upgrading from Guzzle 6 to 7, be aware of these breaking changes:

  1. PHP Version: Ensure your environment runs PHP >= 7.2.5
  2. Method Signatures: Some method signatures have changed due to type hints
  3. Exception Handling: Update catch blocks to handle specific exception types
  4. Middleware: Some middleware interfaces may have changed

Migration Steps

  1. Update Composer: Change your composer.json requirement:
   {
       "require": {
           "guzzlehttp/guzzle": "^7.0"
       }
   }
  1. Run Tests: Execute your test suite to identify breaking changes
  2. Update Exception Handling: Utilize the new exception hierarchy
  3. Review Custom Middleware: Ensure compatibility with the improved middleware system

Compatibility Layer

For applications that need to support both versions temporarily:

use GuzzleHttp\Client;
use GuzzleHttp\Exception\RequestException;

try {
    $response = $client->request('GET', $url);
} catch (RequestException $e) {
    // This works with both Guzzle 6 and 7
    if ($e->hasResponse()) {
        $statusCode = $e->getResponse()->getStatusCode();
        // Handle based on status code
    }
}

Conclusion

Guzzle 7 represents a significant modernization of the library, bringing improved type safety, better standards compliance, and enhanced performance. While the upgrade requires PHP 7.2.5+, the benefits in terms of code reliability, performance, and maintainability make it a worthwhile investment for modern PHP applications.

Before upgrading, thoroughly test your application and review the official Guzzle upgrade guide for detailed migration instructions.

Get Started Now

WebScraping.AI provides rotating proxies, Chromium rendering and built-in HTML parser for web scraping
Icon