Add meaningful API root endpoint (#1771)

application/src/Controller/ApiController.php

@@ -8,6 +8,7 @@
 use Laminas\Mvc\Controller\AbstractRestfulController;
 use Laminas\Mvc\MvcEvent;
 use Laminas\Stdlib\RequestInterface as Request;
+use Laminas\View\Model\ViewModel;
 
 class ApiController extends AbstractRestfulController
 {
@@ -57,6 +58,19 @@ public function getList()
     {
         $this->setBrowseDefaults('id', 'asc');
         $resource = $this->params()->fromRoute('resource');
+
+        if (null === $resource) {
+            $view = new ViewModel;
+            $view->setTerminal(true);
+            $view->setTemplate('omeka/api/root');
+            $apiResources = $this->api->search('api_resources')->getContent();
+            usort($apiResources, function ($a, $b) {
+                return strcmp($a->id(), $b->id());
+            });
+            $view->setVariable('apiResources', $apiResources);
+            return $view;
+        }
+
         $query = $this->params()->fromQuery();
         $response = $this->api->search($resource, $query);
 

application/view/omeka/api/root.phtml

@@ -0,0 +1,15 @@
+<h1>Omeka S REST API</h1>
+<p><?php echo $this->translate('This is the REST API root endpoint for this Omeka S installation. Below is a list of available API resources and links to their endpoints. Some resources and features require authentication.'); ?></p>
+<ul>
+    <?php foreach ($apiResources as $apiResource): ?>
+    <li><?php echo $this->hyperlink(
+        $apiResource->id(),
+        $this->url('api/default', ['resource' => $apiResource->id()], ['force_canonical' => true, 'query' => ['pretty_print' => true]], true)
+    ); ?></li>
+    <?php endforeach; ?>
+</ul>
+<p><?php echo $this->hyperlink(
+    $this->translate('Omeka S REST API documentation'),
+    'https://omeka.org/s/docs/developer/api/rest_api/',
+    ['target' => '_blank']
+); ?></p>