6-5 讀出指定年度的文章

1. 由於選項上有連結 index.php?year={$year}，所以，點了之後，網址會變成如：index.php?year=2023，也就是我們要讓系統只列出2023年文章即可
2. 由於有新傳入外來變數到 index.php ，所以要新增過濾 $year

   // 變數過濾
   $id = isset($_REQUEST['id']) ? (int) $_REQUEST['id'] : 0;
   $op = isset($_REQUEST['op']) ? htmlspecialchars($_REQUEST['op']) : 'index';
   $category = isset($_REQUEST['category']) ? (int) $_REQUEST['category'] : 0;
   $keyword = isset($_REQUEST['keyword']) ? htmlspecialchars($_REQUEST['keyword']) : '';
   $year = isset($_REQUEST['year']) ? (int) $_REQUEST['year'] : 0;

    

3. 在 index.php 的流程中 index()  函式加入 $year 參數

   // 預設為文章列表
   default:
       list($all_news, $paginator) = index($category, $year, $keyword, $perPage);
       $smarty->assign('all_news', $all_news);
       $smarty->assign('paginator', $paginator);
       break;

    

4. 修改 index.php 的 index() 函式，年度搜尋和關鍵字搜尋其實很類似，只不過只要搜尋 date 欄位即可，而且，年度一定在左邊，只有右邊日期會不同，所以把 % 萬用字元放到右邊即可。

   // 列出所有文章
   function index($category = 0, $year = 0, $keyword = '', $perPage = 10)
   {
       global $pdo;
       // 計算總資料數
       try {
           if ($year) {
               $stmt = $pdo->prepare('SELECT count(*) FROM `news` WHERE `date` LIKE ?');
               $stmt->execute(["$year%"]);
           } elseif ($keyword) {
               $stmt = $pdo->prepare('SELECT count(*) FROM `news` WHERE `title` LIKE ? OR `content` LIKE ? OR `author` LIKE ?');
               $stmt->execute(["%$keyword%", "%$keyword%", "%$keyword%"]);
           } elseif ($category) {
               $stmt = $pdo->prepare('SELECT count(*) FROM `news` WHERE `category`=?');
               $stmt->execute([$category]);
           } else {
               $stmt = $pdo->prepare('SELECT count(*) FROM `news`');
               $stmt->execute();
           }
           list($totalCount) = $stmt->fetch(PDO::FETCH_NUM);
           // 產生分頁物件
           $pagination = new Pagination(['totalCount' => $totalCount, 'perPage' => $perPage]);
           // 產生分頁工具列
           ob_start();
           Paginator::widget(['pagination' => $pagination]);
           $paginator = ob_get_clean();
       } catch (PDOException $e) {
           die("計算總資料數失敗：" . $e->getMessage());
       }
   
       try {
           if ($year) {
               $stmt = $pdo->prepare('SELECT * FROM `news` WHERE `date` LIKE ? LIMIT ?, ?');
               $stmt->execute(["$year%", $pagination->offset, $pagination->limit]);
           } elseif ($keyword) {
               $stmt = $pdo->prepare('SELECT * FROM `news` WHERE `title` LIKE ? OR `content` LIKE ? OR `author` LIKE ? ORDER BY `date` DESC LIMIT ?, ?');
               $stmt->execute(["%$keyword%", "%$keyword%", "%$keyword%", $pagination->offset, $pagination->limit]);
           } elseif ($category) {
               $stmt = $pdo->prepare('SELECT * FROM `news` WHERE `category`=? ORDER BY `date` DESC LIMIT ?, ?');
               $stmt->execute([$category, $pagination->offset, $pagination->limit]);
           } else {
               $stmt = $pdo->prepare('SELECT * FROM `news` ORDER BY `date` DESC LIMIT ?, ?');
               $stmt->execute([$pagination->offset, $pagination->limit]);
           }
           $all_news = [];
           $news = $stmt->fetchAll();
           foreach ($news as $row) {
               $media = $row['media'];
               unset($row['media']);
               $row = array_map('htmlspecialchars', $row);
               $row['files'] = json_decode($media, true);
               $all_news[] = $row;
           }
   
       } catch (PDOException $e) {
           echo "資料庫連接錯誤：" . $e->getMessage();
       }
       return [$all_news, $paginator];
   }

5. 如此就大功告成了！
6. 前台顯示頁面至此算是完成了！