Files
webprogrammierung/php/model/DatabaseArticleManager.php
niklas.ortmann 3d50e6e3b3 ArticleManager um LIKES erweitert...
Einführung einer dynamischen Like-Funktion für Beiträge
2026-06-17 12:26:18 +02:00

449 lines
14 KiB
PHP

<?php
require_once 'ArticleManagerDAO.php';
require_once 'Article.php';
/**
* Klasse: Eine SQLLite3 Lösung des ArticleManagerDAO.
*
* @author Niklas Ortmann
*/
class DatabaseArticleManager implements ArticleManagerDAO {
private static $instance = null;
/**
* Konstruktor
*
* Erstellt die Datenbankverbindung und die Tabelle articles.
* @throws InternalServerErrorException
*/
public function __construct()
{
if (!file_exists(__DIR__ . '/../../db/articles.db')) {
try {
$db = $this->getConnection();
// Tabelle für Beiträge
$db->exec("
CREATE TABLE articles (
id INTEGER PRIMARY KEY AUTOINCREMENT,
title TEXT,
content TEXT,
author TEXT,
category TEXT,
tags TEXT,
created TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);");
// Tabelle für Likes
$db->exec("
CREATE TABLE likes (
article_id INTEGER,
user_id TEXT,
PRIMARY KEY (article_id, user_id),
FOREIGN KEY (article_id) REFERENCES articles(id) ON DELETE CASCADE
);");
unset($db);
} catch (PDOException $e) {
throw new InternalServerErrorException($e->getMessage());
}
}
}
/**
* Baut die Verbindung zur Datenbank auf.
* @throws InternalServerErrorException
*/
private function getConnection()
{
try {
$user = 'root';
$pw = null;
$dsn = 'sqlite:' . __DIR__ . '/../../db/articles.db';
return new PDO($dsn, $user, $pw);
} catch (PDOException $e) {
throw new InternalServerErrorException($e->getMessage());
}
}
/**
* Gibt die DatabaseArticleManager-Instanz zurück.
* @return DatabaseArticleManager
*/
public static function getInstance()
{
if (self::$instance == null) {
self::$instance = new DatabaseArticleManager();
}
return self::$instance;
}
public function addArticle($title, $content, $author, $category, $tags)
{
try {
$db = $this->getConnection();
$sql = "INSERT INTO articles (title, content, author, category, tags)
VALUES (:title, :content, :author, :category, :tags);";
$command = $db->prepare($sql);
if (!$command) {
throw new InternalServerErrorException("internal_error");
}
// Verknüpft die übergebenen Parameter exakt mit den SQL-Platzhaltern
$success = $command->execute([
":title" => $title,
":content" => $content,
":author" => $author,
":category" => $category,
":tags" => $tags
]);
if (!$success) {
throw new InternalServerErrorException("internal_error");
}
return intval($db->lastInsertId());
} catch (PDOException $e) {
throw new InternalServerErrorException($e->getMessage());
}
}
public function updateArticle($id, $article, $author)
{
if (empty($article)) {
throw new InternalServerErrorException("internal_error");
}
// Berechtigungsprüfung analog zur lokalen Implementierung:
if ($article->getAuthor() !== $author) {
throw new UnauthorizedAccessException("unauthorized_access");
}
try {
$db = $this->getConnection();
$sql = "UPDATE articles
SET title = :title, content = :content, author = :author, category = :category, tags = :tags
WHERE id = :id;";
$command = $db->prepare($sql);
if (!$command) {
throw new InternalServerErrorException("internal_error");
}
$success = $command->execute([
":id" => $id,
":title" => $article->getTitle(),
":content" => $article->getContent(),
":author" => $author,
":category" => $article->getCategory(),
":tags" => $article->getTags()
]);
// rowCount() prüft, ob eine Zeile mit dieser ID existierte und geändert werden konnte
if (!$success || $command->rowCount() === 0) {
// Falls die ID nicht existiert, prüfen wir, ob sie überhaupt da ist
if (!$this->getArticle($id)) {
throw new NotFoundException("missing_id");
}
}
} catch (PDOException $e) {
throw new InternalServerErrorException("internal_error");
}
}
public function deleteArticle($id, $author)
{
$article = $this->getArticle($id);
if (empty($article)) {
throw new NotFoundException("not_found_article");
}
// Berechtigungsprüfung:
if ($article->getAuthor() !== $author) {
throw new UnauthorizedAccessException("unauthorized_access");
}
try {
$db = $this->getConnection();
$sql = "DELETE FROM articles WHERE id = :id;";
$command = $db->prepare($sql);
if (!$command) {
throw new InternalServerErrorException("internal_error");
}
if (!$command->execute([":id" => $id])) {
throw new InternalServerErrorException("internal_error");
}
} catch (PDOException $exc) {
throw new InternalServerErrorException("internal_error");
}
}
public function getArticle($id)
{
try {
$db = $this->getConnection();
$sql = "SELECT * FROM articles WHERE id = :id;";
$command = $db->prepare($sql);
if (!$command) {
throw new InternalServerErrorException("internal_error");
}
$command->execute([":id" => $id]);
$row = $command->fetch(PDO::FETCH_ASSOC);
if ($row) {
$likes = $this->getLikesForArticle(intval($row['id']));
return new Article(
intval($row['id']),
$row['title'],
$row['content'],
$row['author'],
$row['category'],
$row['tags'],
$row['created'],
$likes
);
}
return null;
} catch (PDOException $e) {
throw new InternalServerErrorException("internal_error");
}
}
public function getAllArticles()
{
try {
$db = $this->getConnection();
$sql = "SELECT * FROM articles;";
$command = $db->query($sql);
if (!$command) {
throw new InternalServerErrorException("internal_error");
}
$rows = $command->fetchAll(PDO::FETCH_ASSOC);
$articles = [];
foreach ($rows as $row) {
$articles[] = new Article(
intval($row['id']),
$row['title'],
$row['content'],
$row['author'],
$row['category'],
$row['tags'],
$row['created']
);
}
return $articles;
} catch (PDOException $e) {
throw new InternalServerErrorException("internal_error");
}
}
public function getArticlesByAuthor($author)
{
try {
$db = $this->getConnection();
$sql = "SELECT * FROM articles WHERE author = :author;";
$command = $db->prepare($sql);
if (!$command) {
throw new InternalServerErrorException("internal_error");
}
$command->execute([":author" => $author]);
$rows = $command->fetchAll(PDO::FETCH_ASSOC);
$filteredArticles = [];
foreach ($rows as $row) {
$likes = $this->getLikesForArticle(intval($row['id']));
$filteredArticles[] = new Article(
intval($row['id']),
$row['title'],
$row['content'],
$row['author'],
$row['category'],
$row['tags'],
$row['created'],
$likes
);
}
return $filteredArticles;
} catch (PDOException $e) {
throw new InternalServerErrorException("internal_error");
}
}
public function getArticlesByCategory($category)
{
try {
$db = $this->getConnection();
$sql = "SELECT * FROM articles WHERE category = :category;";
$command = $db->prepare($sql);
if (!$command) {
throw new InternalServerErrorException("internal_error");
}
$command->execute([":category" => $category]);
$rows = $command->fetchAll(PDO::FETCH_ASSOC);
$filteredArticles = [];
foreach ($rows as $row) {
$likes = $this->getLikesForArticle(intval($row['id']));
$filteredArticles[] = new Article(
intval($row['id']),
$row['title'],
$row['content'],
$row['author'],
$row['category'],
$row['tags'],
$row['created'],
$likes
);
}
return $filteredArticles;
} catch (PDOException $exc) {
throw new InternalServerErrorException("internal_error");
}
}
public function search(string $keyword): array
{
$cleankeyword = trim($keyword);
// Leeren Suchbegriff sofort abfangen
if ($cleankeyword === '') {
return [];
}
try {
$db = $this->getConnection();
$sql = "SELECT id, title, content, author, category, tags, created
FROM articles
WHERE title LIKE :keyword
OR content LIKE :keyword;";
$command = $db->prepare($sql);
if (!$command) {
throw new InternalServerErrorException("internal_error");
}
// Wildcards für die Suche hinzufügen
$searchParam = '%' . $cleankeyword . '%';
$success = $command->execute([
":keyword" => $searchParam
]);
if (!$success) {
throw new InternalServerErrorException("internal_error");
}
$rows = $command->fetchAll(PDO::FETCH_ASSOC);
$filteredArticles = [];
foreach ($rows as $row) {
$likes = $this->getLikesForArticle(intval($row['id']));
$filteredArticles[] = new Article(
intval($row['id']),
$row['title'] ?? '',
$row['content'] ?? '',
$row['author'] ?? '',
$row['category'] ?? '',
$row['tags'] ?? '',
$row['created'] ?? '',
$likes
);
}
return $filteredArticles;
} catch (PDOException $e) {
throw new InternalServerErrorException("internal_error");
}
}
/**
* Holt alle User-IDs, die einen bestimmten Beitrag geliked haben.
*
* @return String[] UserIDs
* @throws InternalServerErrorException
*/
private function getLikesForArticle(int $articleId): array
{
try {
$db = $this->getConnection();
$sql = "SELECT user_id FROM likes WHERE article_id = :article_id;";
$command = $db->prepare($sql);
$command->execute([':article_id' => $articleId]);
return $command->fetchAll(PDO::FETCH_COLUMN) ?: [];
} catch (PDOException $e) {
return [];
}
}
public function toggleLike(int $articleId, string $userId): bool
{
// prüfen, ob der Artikel überhaupt existiert
$article = $this->getArticle($articleId);
if (!$article) {
throw new NotFoundException("missing_id");
}
try {
$db = $this->getConnection();
// prüfen, ob das Like bereits existiert
$checkSql = "SELECT COUNT(*) FROM likes WHERE article_id = :article_id AND user_id = :user_id;";
$checkCommand = $db->prepare($checkSql);
$checkCommand->execute([
':article_id' => $articleId,
':user_id' => $userId
]);
$hasLiked = (int)$checkCommand->fetchColumn() > 0;
if ($hasLiked) {
// wenn bereits geliked -> Unlike
$deleteSql = "DELETE FROM likes WHERE article_id = :article_id AND user_id = :user_id;";
$deleteCommand = $db->prepare($deleteSql);
$deleteCommand->execute([
':article_id' => $articleId,
':user_id' => $userId
]);
return false; // gibt false zurück, da der Beitrag jetzt nicht mehr geliked ist
} else {
// wenn noch nicht geliked -> Like
$insertSql = "INSERT INTO likes (article_id, user_id) VALUES (:article_id, :user_id);";
$insertCommand = $db->prepare($insertSql);
$insertCommand->execute([
':article_id' => $articleId,
':user_id' => $userId
]);
return true; // gibt true zurück, da der Beitrag jetzt geliked ist
}
} catch (PDOException $e) {
throw new InternalServerErrorException("internal_error");
}
}
}