Laravel 事件阻止更新模型

Question

我有一个Conversation可以设置为私人的。设置为 private 意味着user_idonconversations将被分配一个非空值。如果他有足够的积分，用户可以将对话设置为私人。前端拥有验证逻辑，但我也想在后端进行。我已将事件设置为在模型保存时触发：protected $dispatchesEvents = [    'saving' => ConversationSaving::class,];那个事件没什么特别的：public function __construct(Conversation $conversation){    Log::info("[Event] " . get_class());    $this->conversation = $conversation;}事件服务提供者的逻辑是这样的：ConversationSaving::class      => [    PreventMakingPrivate::class],ConversationMadePrivate::class => [    DeductCreditsForMakingPrivate::class],这个想法是触发更新，如果更新失败，ConversationMadePrivate事件永远不会触发。控制器看起来像这样：$conversation->update(['user_id' => Auth::user()->id]);Log::info('After update');Log::info($conversation->user_id);Log::info($conversation->user_id ? 't':'f');if(!$conversation->user_id){    return response([        'error' => 'Error making private',    ]);}event(new ConversationMadePrivate($conversation));return response([    'conversation' => $conversation->load('messages'),]);现在我在日志中得到的是：[2020-05-16 07:34:41] local.INFO: [Event] App\Events\ConversationSaving [2020-05-16 07:34:41] local.INFO: [Listener] App\Listeners\PreventMakingPrivate  [2020-05-16 07:34:41] local.INFO: [Listener] Not enough credits  [2020-05-16 07:34:41] local.INFO: After update  [2020-05-16 07:34:41] local.INFO: 1  [2020-05-16 07:34:41] local.INFO: t  [2020-05-16 07:34:41] local.INFO: [Event] App\Events\ConversationMadePrivate  [2020-05-16 07:34:41] local.INFO: [Listener] App\Listeners\DeductCreditsForMakingPrivate  所以代码正确地进入监听器并false从返回PreventMakingPrivate，但是模型仍然更新。我也试过设置 onConversation updating而不是saving，但同样的事情发生了。我怎样才能阻止更新？

Answer 1

哦，我明白了。如果有人也需要它，看起来update方法会在成功时返回 1，否则不会返回任何内容。这解决了我的问题：

$response = $conversation->update(['user_id' => Auth::user()->id]);

if(!$response){

    return response([

        'error' => 'Error making private',

    ]);

}