Laravel 6 - 在构造函数中绑定实现数组

Question

我正在尝试将某个接口的一组实现注入订阅者 class。

这是我的服务提供商中的代码：

$this->app->tag([TrackerServiceOne::class, TrackerServiceTwo::class], 'trackers');
$this->app->bind(EventSubscriber::class, function ($app) {
    return new EventSubscriber($this->app->tagged('trackers'));
});

这是我的 EventSubscriber class:

中的构造函数

public function __construct(array $trackers)
{
    $this->trackers = $trackers;
}

这是我遇到的错误：

Unresolvable dependency resolving [Parameter #0 [ <required> array $trackers ]] in class Path\To\EventSubscriber

Answer 1

尝试使用服务容器中的 makeWith 解析 EventSubscriber 而不是实例化 new 实例：

$this->app->bind(EventSubscriber::class, function ($app) {
    return $app->makeWith(EventSubscriber::class, [
        'trackers' => $this->app->tagged('trackers')
    ]);
});

这应该正确地将 $trackers 参数注入到 EventSubscriber 的构造函数中。

来自Docs：

If some of your class' dependencies are not resolvable via the container, you may inject them by passing them as an associative array into the makeWith method:

$api = $this->app->makeWith('HelpSpot\API', ['id' => 1]);

更新

在尝试 Laravel 6 之后，我设法让它工作了，尽管与文档中描述的不完全一样：

app()->bind('TrackerServiceOne', function () {
  return new TrackerServiceOne();
});

app()->bind('TrackerServiceTwo', function () {
  return new TrackerServiceTwo();
});

app()->tag([
  'TrackerServiceOne', 
  'TrackerServiceTwo'
], 'trackers');

app()->bind(EventSubscriber::class, function () {
  $trackers = [];

  foreach (app()->tagged('trackers') as $tracker) {
    $trackers[] = $tracker;
  }

  return new EventSubscriber($trackers);
});

$subscriber = resolve(EventSubscriber::class);

dd($subscriber->getTrackers());

Laravel Playground Example

Laravel 6 - 在构造函数中绑定实现数组

Laravel 6 - Bind array of implementations in constructor

php

laravel

dependency-injection

laravel-6