API Proxy

What does it do?

Do you have a consumer (for instance a JavaScript application) that uses a 3rd party API?

• Does that API have all the CORS headers you need?
• Does that API have sufficient caching?
• Does it require an authentication key that you don't want to put in the clear in your JS app?
• Do you wish it returned something different?

This module will help with all those problems. Putting Drupal between your consumer and the 3rd party API will allow you to modify the requests to the 3rd party API and the responses from it.

Usage

You will need to:

• Create the proxy plugin.
• Configure the server plugin.
• Profit.

Create the proxy plugin

In order to connect to a new API you will need to write a new plugin. Take for instance:

namespace Drupal\my_module\Plugin\api_proxy;

use Drupal\api_proxy\Plugin\api_proxy\HttpApiCommonConfigs;
use Drupal\api_proxy\Plugin\HttpApiPluginBase;
use Drupal\Core\Form\SubformStateInterface;
use Symfony\Component\HttpFoundation\Response;

/**
 * The Example API.
 *
 * @HttpApi(
 *   id = "api-slug",
 *   label = @Translation("Example API"),
 *   description = @Translation("Proxies requests to the Example API."),
 *   serviceUrl = "https://api.example.org/v1",
 * )
 */
final class Example extends HttpApiPluginBase {

  use HttpApiCommonConfigs;

  /**
   * {@inheritdoc}
   */
  public function addMoreConfigurationFormElements(array $form, SubformStateInterface $form_state): array {
    $form['auth_token'] = $this->authTokenConfigForm($this->configuration);
    $form['more_stuff'] = ['#type' => 'textfield', '#title' => $this->t('Extra config')];
    return $form;
  }

  /**
   * {@inheritdoc}
   */
  protected function calculateHeaders(array $headers): array {
    $new_headers = parent::calculateHeaders($headers);
    // Modify & add new headers. Here you can add the auth token. Refer to your
    // APIs documentation for expected auth format.
    return $new_headers;
  }

  /**
   * {@inheritdoc}
   */
  public function postprocessOutgoing(Response $response): Response {
    // Modify the response from the API.
    // A common problem is to remove the Transfer-Encoding header.
    // $response->headers->remove('transfer-encoding');
    return $response;
  }

}

Configure the server plugin

Head to /admin/config/services/api-proxy/settings and you should see a configuration form for your proxy. Note that there will be some common configuration options plus the ones specific for this plugin you added in addMoreConfigurationFormElements.

Profit

In your consumer (JS application) instead of making requests to:

https://api.example.org/v1/the-resource/123?setting[foo]=bar&lorem=10

Make them against:

https://your-drupal-install.com/api-proxy/api-slug?_api_proxy_uri=the-resource%2F123%3Fsetting%5Bfoo%5D%3Dbar%26lorem%3D10

Note that you will need to URL encode the the-resource/123?setting[foo]=bar&lorem=10. This results into the-resource%2F123%3Fsetting%5Bfoo%5D%3Dbar%26lorem%3D10.