code challenge 3 solution

CODING-CHALLENGE-4.md

@@ -0,0 +1,18 @@
+# RESTful Webservices in Symfony
+
+## Coding Challenge 4 - HATEOAS
+
+### Tasks
+
+- introduce HATEOAS links for your read and list representations of workshops and attendees
+- use the JSON-HAL format
+
+### Solution
+
+- add a `links` property to the `PaginatedCollection` class (annotate the getter with `#[SerializedName('_links')]`)
+- add `UrlGeneratorInterface` as dependency of `PaginatedCollectionFactory`
+- introduce a `addLink(string $rel, string $href)` method in the `PaginatedCollection` class
+- add links to the created `PaginatedCollection` (self, next, prev, first, last)
+- adjust the AttendeeNormalizer and WorkshopNormalizer and add
+- `$data['_links']['self']['href']` (remember to check for is_array($data))
+- `$data['_links']['collection']['href']` (remember to check for is_array($data))

src/Controller/Attendee/ListController.php

@@ -4,7 +4,8 @@
 
 namespace App\Controller\Attendee;
 
-use App\Repository\AttendeeRepository;
+use App\Pagination\AttendeeCollectionFactory;
+use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpFoundation\Response;
 use Symfony\Component\Routing\Annotation\Route;
 use Symfony\Component\Serializer\SerializerInterface;
@@ -13,18 +14,22 @@
 final class ListController
 {
     public function __construct(
-        private readonly AttendeeRepository $attendeeRepository,
+        private AttendeeCollectionFactory $attendeeCollectionFactory,
         private readonly SerializerInterface $serializer,
     ) {
     }
 
-    public function __invoke(): Response
+    public function __invoke(Request $request): Response
     {
-        $allAttendees = $this->attendeeRepository->findAll();
+        // since 6.3 https://symfony.com/doc/current/controller.html#mapping-the-whole-query-string
+        $attendeeCollection = $this->attendeeCollectionFactory->create(
+            $request->query->getInt('page', 1),
+            $request->query->getInt('size', 10)
+        );
 
-        $serializedAttendees = $this->serializer->serialize($allAttendees, 'json');
+        $serializedAttendeeCollection = $this->serializer->serialize($attendeeCollection, 'json');
 
-        return new Response($serializedAttendees, Response::HTTP_OK, [
+        return new Response($serializedAttendeeCollection, Response::HTTP_OK, [
             'Content-Type' => 'application/json',
         ]);
     }

src/Controller/Workshop/ListController.php

@@ -4,7 +4,8 @@
 
 namespace App\Controller\Workshop;
 
-use App\Repository\WorkshopRepository;
+use App\Pagination\WorkshopCollectionFactory;
+use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpFoundation\Response;
 use Symfony\Component\Routing\Annotation\Route;
 use Symfony\Component\Serializer\SerializerInterface;
@@ -13,18 +14,22 @@
 final class ListController
 {
     public function __construct(
-        private readonly WorkshopRepository $workshopRepository,
+        private readonly WorkshopCollectionFactory $workshopCollectionFactory,
         private readonly SerializerInterface $serializer
     ) {
     }
 
-    public function __invoke(): Response
+    public function __invoke(Request $request): Response
     {
-        $allWorkshops = $this->workshopRepository->findAll();
+        // since 6.3 https://symfony.com/doc/current/controller.html#mapping-the-whole-query-string
+        $workshopCollection = $this->workshopCollectionFactory->create(
+            $request->query->getInt('page', 1),
+            $request->query->getInt('size', 10)
+        );
 
-        $serializedWorkshops = $this->serializer->serialize($allWorkshops, 'json');
+        $serializedWorkshopCollection = $this->serializer->serialize($workshopCollection, 'json');
 
-        return new Response($serializedWorkshops, Response::HTTP_OK, [
+        return new Response($serializedWorkshopCollection, Response::HTTP_OK, [
             'Content-Type' => 'application/json',
         ]);
     }

src/Pagination/AttendeeCollectionFactory.php

@@ -0,0 +1,21 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Pagination;
+
+use App\Repository\AttendeeRepository;
+use Doctrine\Bundle\DoctrineBundle\Repository\ServiceEntityRepositoryInterface;
+
+final class AttendeeCollectionFactory extends PaginatedCollectionFactory
+{
+    public function __construct(
+        private readonly AttendeeRepository $attendeeRepository
+    ) {
+    }
+
+    public function getRepository(): ServiceEntityRepositoryInterface
+    {
+        return $this->attendeeRepository;
+    }
+}

src/Pagination/PaginatedCollection.php

@@ -0,0 +1,19 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Pagination;
+
+final class PaginatedCollection
+{
+    public readonly array $items;
+    public readonly int $total;
+    public readonly int $count;
+
+    public function __construct(\Iterator $items, int $total)
+    {
+        $this->items = iterator_to_array($items);
+        $this->total = $total;
+        $this->count = \count($this->items);
+    }
+}

src/Pagination/PaginatedCollectionFactory.php

@@ -0,0 +1,32 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Pagination;
+
+use Doctrine\Bundle\DoctrineBundle\Repository\ServiceEntityRepositoryInterface;
+use Doctrine\ORM\Tools\Pagination\Paginator;
+
+abstract class PaginatedCollectionFactory
+{
+    abstract public function getRepository(): ServiceEntityRepositoryInterface;
+
+    public function create(int $page, int $size): PaginatedCollection
+    {
+        $query = $this->getRepository()
+            ->createQueryBuilder('u')
+            ->orderBy('u.id', 'asc')
+            ->getQuery()
+        ;
+
+        $paginator = new Paginator($query);
+        $total = count($paginator);
+
+        $paginator
+            ->getQuery()
+            ->setFirstResult($size * ($page - 1))
+            ->setMaxResults($size);
+
+        return new PaginatedCollection($paginator->getIterator(), $total);
+    }
+}

src/Pagination/PaginationInformation.php

@@ -0,0 +1,12 @@
+<?php
+
+namespace App\Pagination;
+
+class PaginationInformation
+{
+    public function __construct(
+        public readonly ?int $page = 1,
+        public readonly ?int $size = 10,
+    ) {
+    }
+}

src/Pagination/WorkshopCollectionFactory.php

@@ -0,0 +1,21 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Pagination;
+
+use App\Repository\WorkshopRepository;
+use Doctrine\Bundle\DoctrineBundle\Repository\ServiceEntityRepositoryInterface;
+
+final class WorkshopCollectionFactory extends PaginatedCollectionFactory
+{
+    public function __construct(
+        private readonly WorkshopRepository $workshopRepository
+    ) {
+    }
+
+    public function getRepository(): ServiceEntityRepositoryInterface
+    {
+        return $this->workshopRepository;
+    }
+}

tests/Controller/Attendee/ListControllerTest.php

@@ -20,4 +20,28 @@ public function test_it_should_list_all_attendees(): void
 
         $this->assertMatchesJsonSnapshot($this->browser->getResponse()->getContent());
     }
+
+    /**
+     * @dataProvider paginationQueryParameterValues
+     */
+    public function test_it_should_paginate_attendees(int $page, int $size): void
+    {
+        $this->loadFixtures([
+            __DIR__.'/fixtures/paginate_attendee.yaml',
+        ]);
+
+        $this->browser->request('GET', sprintf('/attendees?page=%d&size=%d', $page, $size));
+
+        static::assertResponseIsSuccessful();
+
+        $this->assertMatchesJsonSnapshot($this->browser->getResponse()->getContent());
+    }
+
+    public static function paginationQueryParameterValues(): \Generator
+    {
+        yield 'show 1st page, 3 items each' => [1, 3];
+        yield 'show 2nd page, 3 items each' => [2, 3];
+        yield 'show 1st page, 5 items each' => [1, 5];
+        yield 'show 2nd page, 5 items each' => [2, 5];
+    }
 }

tests/Controller/Attendee/__snapshots__/ListControllerTest__test_it_should_list_all_attendees__1.json

@@ -1,18 +1,22 @@
-[
-    {
-        "identifier": "803449f4-9a4c-4ecb-8ce4-cebc804fe70a",
-        "firstname": "Jan",
-        "lastname": "Sch\u00e4dlich",
-        "email": "[email protected]",
-        "workshops": [
-            {
-                "identifier": "abba667a-96ae-4f75-9b71-97819b682e8d",
-                "title": "RESTful Webservices in Symfony",
-                "workshop_date": "2022-06-14",
-                "attendees": [
-                    "Jan Sch\u00e4dlich"
-                ]
-            }
-        ]
-    }
-]
+{
+    "items": [
+        {
+            "identifier": "803449f4-9a4c-4ecb-8ce4-cebc804fe70a",
+            "firstname": "Jan",
+            "lastname": "Sch\u00e4dlich",
+            "email": "[email protected]",
+            "workshops": [
+                {
+                    "identifier": "abba667a-96ae-4f75-9b71-97819b682e8d",
+                    "title": "RESTful Webservices in Symfony",
+                    "workshop_date": "2022-06-14",
+                    "attendees": [
+                        "Jan Sch\u00e4dlich"
+                    ]
+                }
+            ]
+        }
+    ],
+    "total": 1,
+    "count": 1
+}

tests/Controller/Attendee/__snapshots__/ListControllerTest__test_it_should_paginate_attendees with data set show 1st page, 3 items each__1.json

@@ -0,0 +1,27 @@
+{
+    "items": [
+        {
+            "identifier": "4878f198-36ab-4fe3-8189-19662a9764fa",
+            "firstname": "a",
+            "lastname": "1",
+            "email": "[email protected]",
+            "workshops": []
+        },
+        {
+            "identifier": "e942ce16-27c2-494f-9d93-03412da980c5",
+            "firstname": "b",
+            "lastname": "2",
+            "email": "[email protected]",
+            "workshops": []
+        },
+        {
+            "identifier": "4714fb8a-83d8-49af-abbf-7c68fc6c9656",
+            "firstname": "c",
+            "lastname": "3",
+            "email": "[email protected]",
+            "workshops": []
+        }
+    ],
+    "total": 5,
+    "count": 3
+}

tests/Controller/Attendee/__snapshots__/ListControllerTest__test_it_should_paginate_attendees with data set show 1st page, 5 items each__1.json

@@ -0,0 +1,41 @@
+{
+    "items": [
+        {
+            "identifier": "4878f198-36ab-4fe3-8189-19662a9764fa",
+            "firstname": "a",
+            "lastname": "1",
+            "email": "[email protected]",
+            "workshops": []
+        },
+        {
+            "identifier": "e942ce16-27c2-494f-9d93-03412da980c5",
+            "firstname": "b",
+            "lastname": "2",
+            "email": "[email protected]",
+            "workshops": []
+        },
+        {
+            "identifier": "4714fb8a-83d8-49af-abbf-7c68fc6c9656",
+            "firstname": "c",
+            "lastname": "3",
+            "email": "[email protected]",
+            "workshops": []
+        },
+        {
+            "identifier": "65445e8c-a6c6-4955-9eb2-5fb60d6a991e",
+            "firstname": "d",
+            "lastname": "4",
+            "email": "[email protected]",
+            "workshops": []
+        },
+        {
+            "identifier": "3aacd688-5b81-4aba-a5ea-ac7668ba95b6",
+            "firstname": "e",
+            "lastname": "5",
+            "email": "[email protected]",
+            "workshops": []
+        }
+    ],
+    "total": 5,
+    "count": 5
+}

tests/Controller/Attendee/__snapshots__/ListControllerTest__test_it_should_paginate_attendees with data set show 2nd page, 3 items each__1.json

@@ -0,0 +1,20 @@
+{
+    "items": [
+        {
+            "identifier": "65445e8c-a6c6-4955-9eb2-5fb60d6a991e",
+            "firstname": "d",
+            "lastname": "4",
+            "email": "[email protected]",
+            "workshops": []
+        },
+        {
+            "identifier": "3aacd688-5b81-4aba-a5ea-ac7668ba95b6",
+            "firstname": "e",
+            "lastname": "5",
+            "email": "[email protected]",
+            "workshops": []
+        }
+    ],
+    "total": 5,
+    "count": 2
+}

tests/Controller/Attendee/__snapshots__/ListControllerTest__test_it_should_paginate_attendees with data set show 2nd page, 5 items each__1.json

@@ -0,0 +1,5 @@
+{
+    "items": [],
+    "total": 5,
+    "count": 0
+}

tests/Controller/Attendee/fixtures/paginate_attendee.yaml

@@ -0,0 +1,11 @@
+App\Entity\Attendee:
+    attendee_1:
+        __construct: [ '4878f198-36ab-4fe3-8189-19662a9764fa', 'a', '1', '[email protected]' ]
+    attendee_2:
+        __construct: [ 'e942ce16-27c2-494f-9d93-03412da980c5', 'b', '2', '[email protected]' ]
+    attendee_3:
+        __construct: [ '4714fb8a-83d8-49af-abbf-7c68fc6c9656', 'c', '3', '[email protected]' ]
+    attendee_4:
+        __construct: [ '65445e8c-a6c6-4955-9eb2-5fb60d6a991e', 'd', '4', '[email protected]' ]
+    attendee_5:
+        __construct: [ '3aacd688-5b81-4aba-a5ea-ac7668ba95b6', 'e', '5', '[email protected]' ]