Laravel 表单验证限制更新时的图像数量

Question

I need form validation to limit no of images(5) per item. My validation works when I am adding a new item but does not work while I update. when I update it can add more than 5 images. here is my code --

Controller

 public function store(Request $request){
    $request->validate([
                'carreg' => 'required|max:10',
                'car_image' => 'array|max:5',
            ]);
            $car = new Car;
      

                ..........................
               ............................
           $car->save();}


public function update(Request $request,id){
        $request->validate([
                    'carreg' => 'required|max:10',
                    'car_image' => 'array|max:5',
                ]);
                $car = Car::find($id);
          
                    .....................
                   ............................
               $car->save();}

Answer 1

The problem is in your code. When you insert the data, it contains the 5 images which names are saved in Database. Now when you are updating, you are again accepting new images. Thats not a problem cause when you inserted the data, you probably got only 3 images. So you can allow users to update the database with another 2 images. But to do so, you've to check the database before storing the images at update.

So according to your code's 1st part

public function store(Request $request){
    $request->validate([
                'carreg' => 'required|max:10',
                'car_image' => 'array|max:5',
            ]);
            $car = new Car;
        ....................................
        ......Data is saving to database with 
        ......5/4/3/2/1/0 images depending on your code.......
        ...........................

           $car->save();
}

So in your 2nd part of the code has to be modified like this

public function update(Request $request,id){
        $request->validate([
                    'carreg' => 'required|max:10',
                    'car_image' => 'array|max:5',
                ]);
                $car = Car::find($id);
          
                    .....................
                   .....Check if the car has 5/4/3/2/1/0 image in the database.
                   ..... If it has less than 5 images  
                   ......allow (5-image already uploaded) amount of images to upload
                   ..... If user has selected more than the desired amount of image,
                   ......you can upload first nth desired images or return error 
                   ......to user to upload valid amount of file ....
               
              $car->save();
 }

If the user already uploaded 5 images, in edit form, do not show file upload field (hide it, or use if condition to propagate in HTML). You can also use Javascript to allow certain amount of file to select to upload also.

Answer 2

You should check the number of images available, before validate, ex:

function update(Request $request, $id)
{
    $car = Car::find($id);
    // length car_image
    $length = count($car->car_image);
    $max = 5 - $length;

    $request->validate([
        'carreg' => 'required|max:10',
        'car_image' => 'array|max:' . $max,
    ]);

    $car->save();
}