5-2-3 建立縮圖並產生json資料

1. 為了避免圖片太大，我們可以在上傳的過程中縮圖一下AI有幫我們設計一個縮圖的函數：

   function resizeImage(string $sourcePath, string $destPath, int $targetWidth): bool
   {
       list($width, $height) = getimagesize($sourcePath);
       $ratio = $targetWidth / $width;
       $targetHeight = intval($height * $ratio);
   
       $sourceImage = imagecreatefromstring(file_get_contents($sourcePath));
       $destImage = imagecreatetruecolor($targetWidth, $targetHeight);
   
       imagecopyresampled($destImage, $sourceImage, 0, 0, 0, 0, $targetWidth, $targetHeight, $width, $height);
   
       $result = imagejpeg($destImage, $destPath, 90);
   
       imagedestroy($sourceImage);
       imagedestroy($destImage);
   
       return $result;
   }

    

2. 在 store() 中，建立目錄後，判斷若是上傳檔案格式為圖片，那就進行縮圖，我們分別將縮圖寬度改為1024和320。

   $uploadDir = "uploads/{$id}/";
   if (!is_dir($uploadDir)) {
       mkdir($uploadDir, 0777, true);
   }
   
   $mediaJson = [];
   
   if ($_POST['upload_type'] === 'image' && !empty($_FILES['image_files']['name'])) {
       foreach ($_FILES['image_files']['name'] as $key => $name) {
           $tmpName = $_FILES['image_files']['tmp_name'][$key];
           if ($_FILES['image_files']['error'][$key] === UPLOAD_ERR_OK) {
               $extension = pathinfo($name, PATHINFO_EXTENSION);
               $newName = uniqid() . '.' . $extension;
               $destination = $uploadDir . $newName;
   
               // 移動上傳的文件
               move_uploaded_file($tmpName, $destination);
   
               // 創建主圖（寬度800px）
               $mainImage = $uploadDir . 'main_' . $newName;
               resizeImage($destination, $mainImage, 1024);
   
               // 創建縮略圖（寬度200px）
               $thumbImage = $uploadDir . 'thumb_' . $newName;
               resizeImage($destination, $thumbImage, 320);
   
               // 刪除原始上傳的文件
               unlink($destination);
   
               $mediaJson[$mainImage] = $thumbImage;
           }
       }
   }

    

3. 最後，順便產生json內容，並且存入到該筆資中，如此，日後我們就可以簡單的掌握該新聞有哪些圖片了

   if (!empty($mediaJson)) {
       $updateSql = "UPDATE school_news SET media = ? WHERE id = ?";
       $updateStmt = $pdo->prepare($updateSql);
       $updateStmt->execute([json_encode($mediaJson), $id]);
   }