Flutter Laravel API update user

Question

I tried to make crud, so how to update a user without changing his photo because if I pass a photo the update works perfectly but if I didn't pass the photo I got Exception: Invalid image data and the value of photo change in database.

Here is my Laravel code

$product=Products::findOrFail($id);
    $validator = Validator::make($request->all(), [
        'name' => 'required',
        'price'=>'required',
        'detail' => 'required',
        'quantity' => 'required',
        'discount' => 'required'
    ]);
    $input = $request->all();
    if(!is_null($input['photo'])){
        $image = $input['photo'];
        $image = str_replace('data:image/png;base64,', '', $image);
        $image = str_replace(' ', '+', $image);
        $imageName = Str::random(50).'.'.'png';
        if(!is_dir('/uploads/products')) {

            mkdir('/uploads/products', 0755, true);
        }
        Storage::disk('public_uploads')->delete($product->photo);
        Storage::disk('public_uploads')->put($imageName, base64_decode($image));

        $product->photo = $imageName;

    $product->name = $input['name'];
    $product->price = $input['price'];
    $product->detail = $input['detail'];
    $product->quantity = $input['quantity'];
    $product->update();

Answer 1

If statement should be like this

if($request->hasFile('photo')){
    //
}

instead of this

if(!is_null($input['photo'])){
    //
}

https://laravel.com/docs/8.x/requests#files