Drupal 8/9 and Guzzle HTTP client library

Components

Making a simple HTTP Get request in Drupal 8 or 9 is super easy thanks to the Guzzle library. This library has been added to Drupal core a long time ago, and it replaced the much less powerful drupal_http_request() function. Let's see how to get some data from the Star Wars API:

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

$client = new Client();
$people = [];

try {
  $response = $client->get('https://swapi.dev/api/people');
  $result = json_decode($response->getBody(), TRUE);
  foreach($result['results'] as $item) {
    $people[] = $item['name']; 
  }
}
catch (RequestException $e) {
  // log exception
}

Guzzle can also be accessed through the http_client service and the helper method:

$client = \Drupal::httpClient();

Sending a POST request is also simple and easy.

public function sendOrder(OrderInterface $order) {
  try {
    $response = $this->httpClient->post($url, [
      'form_params' => $data,
    ]);
    $response_data = json_decode($response->getBody()->getContents(), TRUE);

    // do something with data
  }
  catch (RequestException $e) {
    // log exception
  }
}

If you want to log the exception don't use $e->getMessage() because the error message will be truncated. Instead, use this:

$e->getResponse()->getBody()->getContents();

You can also use Guzzle to send files. To send an image file you can do something like this:

try {
  $client = new Client(['headers' => ['X-Auth-Secret-Token' => 'my-secret-token']]);
  $options = [
    'multipart' => [
      [
        'Content-type' => 'multipart/form-data',
        'name' => 'image',
        'contents' => fopen($image->getFileUri(), 'r'),
        'filename' => basename($image->getFileUri()),
      ],
    ],
  ];
  $response = $client->post($api_base_url . 'api/v1/images', $options);
}
catch (\Exception $e) {
  // log exception
}

In this case, the $image variable is an instance of Drupal\file\Entity\File class.