Add catalog_url for redirects to exploreuk-web-app

app/Models/Component.php

@@ -32,6 +32,15 @@ public function __construct(protected $id, private $component_id)
         }
     }
 
+    public static function catalogUrl($dao)
+    {
+        $dao = trim((string) ($dao ?? ''));
+        if ($dao === '') {
+            return null;
+        }
+        return '/catalog/' . rawurlencode($dao);
+    }
+
     public function links()
     {
         global $g_minter;
@@ -126,6 +135,14 @@ public function links()
                         break;
                 }
             }
+            // The dao describes the whole $link_raw record. Iterating $link's
+            // keys avoids re-deriving the image/image_overflow choice above.
+            $catalog_url = self::catalogUrl($link_raw['dao'] ?? null);
+            if ($catalog_url !== null) {
+                foreach (array_keys($link) as $field) {
+                    $link[$field]['catalog_url'] = $catalog_url;
+                }
+            }
             $links[] = $link;
         }
         $this->has_image_overflow =

tests/CatalogUrlTest.php

@@ -0,0 +1,36 @@
+<?php
+
+namespace Tests\Unit;
+
+use PHPUnit\Framework\TestCase;
+use App\Models\Component;
+
+class CatalogUrlTest extends TestCase
+{
+    public function testPageLevelDaoIsPassedThroughVerbatim(): void
+    {
+        $this->assertSame(
+            '/catalog/xt7x3f4knz7q_1_1',
+            Component::catalogUrl('xt7x3f4knz7q_1_1')
+        );
+    }
+
+    public function testMissingDaoYieldsNull(): void
+    {
+        $this->assertNull(Component::catalogUrl(null));
+    }
+
+    public function testEmptyDaoYieldsNullRatherThanBareCatalogPath(): void
+    {
+        $this->assertNull(Component::catalogUrl(''));
+        $this->assertNull(Component::catalogUrl('   '));
+    }
+
+    public function testDaoIsUrlEncoded(): void
+    {
+        $this->assertSame(
+            '/catalog/odd%20id%3F1',
+            Component::catalogUrl('odd id?1')
+        );
+    }
+}