code challenge 3 solution

Author: jschaedl

CODING-CHALLENGE-3.md

@@ -11,4 +11,4 @@
 - introduce query params `page` and `size` in your ListControllers
 - use the Doctrine Paginator to paginate the workshop and attendee lists
 - implement a `PaginatedCollection` object and add the properties `items`, `total` and `count`
-- implement a `PaginationFactory` to encapsulate your pagination logic
+- implement a `PaginatedCollectionFactory` to encapsulate your pagination logic

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 `PaginationFactory`
+- 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['_link']['self']['href']` (remember to check for is_array($data))
+- `$data['_link']['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 +14,21 @@
 final class ListController
 {
     public function __construct(
-        private AttendeeRepository $attendeeRepository,
+        private AttendeeCollectionFactory $attendeeCollectionFactory,
         private SerializerInterface $serializer,
     ) {
     }
 
-    public function __invoke(): Response
+    public function __invoke(Request $request): Response
     {
-        $allAttendees = $this->attendeeRepository->findAll();
+        $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 +14,21 @@
 final class ListController
 {
     public function __construct(
-        private WorkshopRepository $workshopRepository,
+        private WorkshopCollectionFactory $workshopCollectionFactory,
         private SerializerInterface $serializer,
     ) {
     }
 
-    public function __invoke(): Response
+    public function __invoke(Request $request): Response
     {
-        $allWorkshops = $this->workshopRepository->findAll();
+        $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 AttendeeRepository $attendeeRepository
+    ) {
+    }
+
+    public function getRepository(): ServiceEntityRepositoryInterface
+    {
+        return $this->attendeeRepository;
+    }
+}

src/Pagination/PaginatedCollection.php

@@ -0,0 +1,34 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Pagination;
+
+final class PaginatedCollection
+{
+    private array $items;
+    private int $total;
+    private int $count;
+
+    public function __construct(\Iterator $items, int $total)
+    {
+        $this->items = iterator_to_array($items);
+        $this->total = $total;
+        $this->count = \count($this->items);
+    }
+
+    public function getItems(): array
+    {
+        return $this->items;
+    }
+
+    public function getTotal(): int
+    {
+        return $this->total;
+    }
+
+    public function getCount(): int
+    {
+        return $this->count;
+    }
+}

src/Pagination/PaginatedCollectionFactory.php

@@ -0,0 +1,28 @@
+<?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')->getQuery();
+
+        $paginator = new Paginator($query);
+        $total = count($paginator);
+
+        $paginator
+            ->getQuery()
+            ->setFirstResult($size * ($page - 1))
+            ->setMaxResults($size);
+
+        return new PaginatedCollection($paginator->getIterator(), $total);
+    }
+}

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 WorkshopRepository $workshopRepository
+    ) {
+    }
+
+    public function getRepository(): ServiceEntityRepositoryInterface
+    {
+        return $this->workshopRepository;
+    }
+}

tests/Controller/Attendee/ListControllerTest.php

@@ -20,4 +20,30 @@ 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 function paginationQueryParameterValues(): \Generator
+    {
+        yield 'show 1st page 10 items each' => [1, 10];
+        yield 'show 2nd page 10 items each' => [2, 10];
+        yield 'show 3rd page 10 items each' => [3, 10];
+        yield 'show 1st page 5 items each' => [1, 5];
+        yield 'show 4th page 5 items each' => [4, 5];
+        yield 'show 5th page 5 items each' => [5, 5];
+    }
 }

tests/Controller/Attendee/__snapshots__/ListControllerTest__test_it_should_paginate_attendees with data set show 1st page 10 items each__1.json

@@ -0,0 +1,76 @@
+{
+    "items": [
+        {
+            "identifier": "0b13e52d-b058-32fb-8507-10dec634a07c",
+            "firstname": "Tianna",
+            "lastname": "Ziemann",
+            "email": "rubye76@hotmail.com",
+            "workshops": []
+        },
+        {
+            "identifier": "3167f744-197b-3c9b-9419-71e5daf2ea18",
+            "firstname": "Maeve",
+            "lastname": "Hartmann",
+            "email": "wkohler@johnson.com",
+            "workshops": []
+        },
+        {
+            "identifier": "42610729-5cd9-35f3-86bc-ec9158e1797e",
+            "firstname": "Justus",
+            "lastname": "Thiel",
+            "email": "ikoelpin@hotmail.com",
+            "workshops": []
+        },
+        {
+            "identifier": "77c5eb68-1ea8-3561-8cc8-aa7296a10f27",
+            "firstname": "Dianna",
+            "lastname": "Dach",
+            "email": "osinski.heath@mccullough.com",
+            "workshops": []
+        },
+        {
+            "identifier": "1ef2b096-6263-3cd5-87c8-510a91cd114b",
+            "firstname": "Kathleen",
+            "lastname": "Bogan",
+            "email": "mohammed.carter@gmail.com",
+            "workshops": []
+        },
+        {
+            "identifier": "54a4eed2-9608-3fca-ac16-bdb51b5bc348",
+            "firstname": "Esteban",
+            "lastname": "Von",
+            "email": "sgislason@kuhn.com",
+            "workshops": []
+        },
+        {
+            "identifier": "68140326-e25d-3a9a-be91-54e736e31d69",
+            "firstname": "Lambert",
+            "lastname": "Steuber",
+            "email": "elinore23@hotmail.com",
+            "workshops": []
+        },
+        {
+            "identifier": "75e73073-fb97-3730-a317-68b740376cf6",
+            "firstname": "Marta",
+            "lastname": "Kulas",
+            "email": "oran53@hotmail.com",
+            "workshops": []
+        },
+        {
+            "identifier": "279458a4-0701-3cb9-bbb5-76f77c85d61f",
+            "firstname": "Cornelius",
+            "lastname": "Mosciski",
+            "email": "ethelyn92@yahoo.com",
+            "workshops": []
+        },
+        {
+            "identifier": "0a3944ce-2c0d-3904-9199-ae41a9ef9980",
+            "firstname": "Wilburn",
+            "lastname": "Rempel",
+            "email": "ogutmann@adams.org",
+            "workshops": []
+        }
+    ],
+    "total": 20,
+    "count": 10
+}