add new demo symfony files

app/src/Repository/PostRepository.php

@@ -0,0 +1,97 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace App\Repository;
+
+use App\Entity\Post;
+use App\Entity\Tag;
+use App\Pagination\Paginator;
+use Doctrine\Bundle\DoctrineBundle\Repository\ServiceEntityRepository;
+use Doctrine\Persistence\ManagerRegistry;
+use function Symfony\Component\String\u;
+
+/**
+ * This custom Doctrine repository contains some methods which are useful when
+ * querying for blog post information.
+ *
+ * See https://symfony.com/doc/current/doctrine.html#querying-for-objects-the-repository
+ *
+ * @author Ryan Weaver <weaverryan@gmail.com>
+ * @author Javier Eguiluz <javier.eguiluz@gmail.com>
+ * @author Yonel Ceruto <yonelceruto@gmail.com>
+ */
+class PostRepository extends ServiceEntityRepository
+{
+    public function __construct(ManagerRegistry $registry)
+    {
+        parent::__construct($registry, Post::class);
+    }
+
+    public function findLatest(int $page = 1, Tag $tag = null): Paginator
+    {
+        $qb = $this->createQueryBuilder('p')
+            ->addSelect('a', 't')
+            ->innerJoin('p.author', 'a')
+            ->leftJoin('p.tags', 't')
+            ->where('p.publishedAt <= :now')
+            ->orderBy('p.publishedAt', 'DESC')
+            ->setParameter('now', new \DateTime())
+        ;
+
+        if (null !== $tag) {
+            $qb->andWhere(':tag MEMBER OF p.tags')
+                ->setParameter('tag', $tag);
+        }
+
+        return (new Paginator($qb))->paginate($page);
+    }
+
+    /**
+     * @return Post[]
+     */
+    public function findBySearchQuery(string $query, int $limit = Paginator::PAGE_SIZE): array
+    {
+        $searchTerms = $this->extractSearchTerms($query);
+
+        if (0 === \count($searchTerms)) {
+            return [];
+        }
+
+        $queryBuilder = $this->createQueryBuilder('p');
+
+        foreach ($searchTerms as $key => $term) {
+            $queryBuilder
+                ->orWhere('p.title LIKE :t_'.$key)
+                ->setParameter('t_'.$key, '%'.$term.'%')
+            ;
+        }
+
+        return $queryBuilder
+            ->orderBy('p.publishedAt', 'DESC')
+            ->setMaxResults($limit)
+            ->getQuery()
+            ->getResult();
+    }
+
+    /**
+     * Transforms the search string into an array of search terms.
+     */
+    private function extractSearchTerms(string $searchQuery): array
+    {
+        $searchQuery = u($searchQuery)->replaceMatches('/[[:space:]]+/', ' ')->trim();
+        $terms = array_unique($searchQuery->split(' '));
+
+        // ignore the search terms that are too short
+        return array_filter($terms, function ($term) {
+            return 2 <= $term->length();
+        });
+    }
+}