今天我们来看一下EventProcessor的实现。
/**
* Handle event register
* @return bool
*/
public function handle(): bool
{
if (!$this->application->beforeEvent()) {
CLog::warning('Stop event processor by beforeEvent return false');
return false;
}
/** @var EventManager $eventManager */
$eventManager = bean('eventManager');
[$count1, $count2] = ListenerRegister::register($eventManager);
CLog::info('Event manager initialized(%d listener, %d subscriber)', $count1, $count2);
// Trigger a app init event
Swoft::trigger(SwoftEvent::APP_INIT_COMPLETE);
return $this->application->afterEvent();
}
获取eventManager的Bean实例，对应为Swoft\Event\Manager\EventManager类。
[$count1, $count2] = ListenerRegister::register($eventManager);
调用ListenerRegister类的register方法。
/**
* @param EventManager $em
*
* @return array
*/
public static function register(EventManager $em): array
{
foreach (self::$listeners as $className => $eventInfo) {
$listener = Swoft::getSingleton($className);
if (!$listener instanceof EventHandlerInterface) {
throw new RuntimeException("The event listener class '{$className}' must be instanceof EventHandlerInterface");
}
$em->addListener($listener, $eventInfo);
}
foreach (self::$subscribers as $className) {
$subscriber = Swoft::getSingleton($className);
if (!$subscriber instanceof EventSubscriberInterface) {
throw new RuntimeException("The event subscriber class '{$className}' must be instanceof EventSubscriberInterface");
}
$em->addSubscriber($subscriber);
}
$count1 = count(self::$listeners);
$count2 = count(self::$subscribers);
// Clear data
self::$listeners = self::$subscribers = [];
return [$count1, $count2];
}
遍历ListenerRegister类下的$listeners和$subscribers属性，绑定事件到eventManager的Bean实例上。
这里的$listeners和$subscribers是从哪里来的呢？
这里以http-server为例。
在swoft-component-2.0.5\src\http-server\src\Listener目录下，存在下面三个文件。
AfterRequestListener.php
AppInitCompleteListener.php
BeforeRequestListener.php
这里我们以AppInitCompleteListener.php为例。
<?php
namespace Swoft\Http\Server\Listener;
use function bean;
use ReflectionException;
use Swoft\Bean\Exception\ContainerException;
use Swoft\Event\Annotation\Mapping\Listener;
use Swoft\Event\EventHandlerInterface;
use Swoft\Event\EventInterface;
use Swoft\Http\Server\Exception\HttpServerException;
use Swoft\Http\Server\Middleware\MiddlewareRegister;
use Swoft\Http\Server\Router\Router;
use Swoft\Http\Server\Router\RouteRegister;
use Swoft\SwoftEvent;
/**
* Class AppInitCompleteListener
* @since 2.0
*
* @Listener(SwoftEvent::APP_INIT_COMPLETE)
*/
class AppInitCompleteListener implements EventHandlerInterface
{
/**
* @param EventInterface $event
*
* @throws ContainerException
* @throws ReflectionException
* @throws HttpServerException
*/
public function handle(EventInterface $event): void
{
/** @var Router $router Register HTTP routes */
$router = bean('httpRouter');
RouteRegister::registerRoutes($router);
// Register middleware
MiddlewareRegister::register();
}
}
可以看到这里通过@Listener(SwoftEvent::APP_INIT_COMPLETE)，使用了Swoft\Event\Annotation\Mapping\Listener类注解，对应的注解解析类为Swoft\Event\Annotation\Parser\ListenerParser。
<?php declare(strict_types=1);
namespace Swoft\Event\Annotation\Parser;
use Doctrine\Common\Annotations\AnnotationException;
use Swoft\Annotation\Annotation\Mapping\AnnotationParser;
use Swoft\Annotation\Annotation\Parser\Parser;
use Swoft\Bean\Annotation\Mapping\Bean;
use Swoft\Event\Annotation\Mapping\Listener;
use Swoft\Event\ListenerRegister;
/**
* Class ListenerParser
*
* @since 2.0
*
* @AnnotationParser(Listener::class)
*/
class ListenerParser extends Parser
{
/**
* @param int $type
* @param Listener $annotation
*
* @return array
* @throws AnnotationException
*/
public function parse(int $type, $annotation): array
{
if ($type !== self::TYPE_CLASS) {
throw new AnnotationException('`@Listener` must be defined on class!');
}
// collect listeners
ListenerRegister::addListener($this->className, [
// event name => listener priority
$annotation->getEvent() => $annotation->getPriority()
]);
return [$this->className, $this->className, Bean::SINGLETON, ''];
}
}
/**
* @param string $className
* @param array $definition [event name => listener priority]
*/
public static function addListener(string $className, array $definition = []): void
{
// Collect listeners
self::$listeners[$className] = $definition;
}
可以看到这里通过ListenerRegister::addListener方法，往ListenerRegister上注册了$listeners属性。
属性$listeners和$subscribers的值，都是通过注解解析得来。
这里我们回到EventProcessor类的handle方法。
// Trigger a app init event
Swoft::trigger(SwoftEvent::APP_INIT_COMPLETE);
trigger的方法定义如下。
/**
* Trigger an swoft application event
*
* @param string|EventInterface $event eg: 'app.start' 'app.stop'
* @param null|mixed $target
* @param array $params
*
* @return EventInterface
*/
public static function trigger($event, $target = null, ...$params): EventInterface
{
/** @see EventManager::trigger() */
return BeanFactory::getSingleton('eventManager')->trigger($event, $target, $params);
}
这里调用了eventManager这个Bean实例的trigger方法。
/**
* Trigger an event. Can accept an EventInterface or will create one if not passed
*
* @param string|EventInterface $event 'app.start' 'app.stop'
* @param mixed|string $target It is object or string.
* @param array|mixed $args
*
* @return EventInterface
* @throws InvalidArgumentException
*/
public function trigger($event, $target = null, array $args = []): EventInterface
{
if ($isString = is_string($event)) {
$name = trim($event);
} elseif ($event instanceof EventInterface) {
$name = trim($event->getName());
} else {
throw new InvalidArgumentException('Invalid event params for trigger event handler');
}
$shouldCall = [];
// Have matched listener
if (isset($this->listenedEvents[$name])) {
$shouldCall[$name] = '';
}
// Like 'app.db.query' => prefix: 'app.db'
if ($pos = strrpos($name, '.')) {
$prefix = substr($name, 0, $pos);
// Have a wildcards listener. eg 'app.db.*'
$wildcardEvent = $prefix . '.*';
if (isset($this->listenedEvents[$wildcardEvent])) {
$shouldCall[$wildcardEvent] = substr($name, $pos + 1);
}
}
// Not found listeners
if (!$shouldCall) {
return $isString ? $this->basicEvent : $event;
}
/** @var EventInterface $event */
if ($isString) {
$event = $this->events[$name] ?? $this->basicEvent;
}
// Initial value
$event->setName($name);
$event->setParams($args);
$event->setTarget($target);
$event->stopPropagation(false);
// Notify event listeners
foreach ($shouldCall as $name => $method) {
$this->triggerListeners($this->listeners[$name], $event, $method);
if ($event->isPropagationStopped()) {
return $event;
}
}
// Have global wildcards '*' listener.
if (isset($this->listenedEvents['*'])) {
$this->triggerListeners($this->listeners['*'], $event);
}
return $event;
}
如果存在对应的事件，调用triggerListeners方法。
/**
* @param array|ListenerQueue $listeners
* @param EventInterface $event
* @param string $method
*/
protected function triggerListeners($listeners, EventInterface $event, string $method = ''): void
{
// $handled = false;
$name = $event->getName();
$callable = false === strpos($name, '.');
// 循环调用监听器，处理事件
foreach ($listeners as $listener) {
if ($event->isPropagationStopped()) {
break;
}
if (is_object($listener)) {
if ($listener instanceof EventHandlerInterface) {
$listener->handle($event);
} elseif ($method && method_exists($listener, $method)) {
$listener->$method($event);
} elseif ($callable && method_exists($listener, $name)) {
$listener->$name($event);
} elseif (method_exists($listener, '__invoke')) {
$listener($event);
}
} elseif (is_callable($listener)) {
$listener($event);
}
}
}
遍历事件回调，执行对应方法。
回到EventProcessor类的handle方法。
// Trigger a app init event
Swoft::trigger(SwoftEvent::APP_INIT_COMPLETE);
这里的事件为SwoftEvent::APP_INIT_COMPLETE，所以这里会执行这个事件下的所有回调。
这里以Swoft\Http\Server\Listener\AppInitCompleteListener为例。
<?php
namespace Swoft\Http\Server\Listener;
use function bean;
use ReflectionException;
use Swoft\Bean\Exception\ContainerException;
use Swoft\Event\Annotation\Mapping\Listener;
use Swoft\Event\EventHandlerInterface;
use Swoft\Event\EventInterface;
use Swoft\Http\Server\Exception\HttpServerException;
use Swoft\Http\Server\Middleware\MiddlewareRegister;
use Swoft\Http\Server\Router\Router;
use Swoft\Http\Server\Router\RouteRegister;
use Swoft\SwoftEvent;
/**
* Class AppInitCompleteListener
* @since 2.0
*
* @Listener(SwoftEvent::APP_INIT_COMPLETE)
*/
class AppInitCompleteListener implements EventHandlerInterface
{
/**
* @param EventInterface $event
*
* @throws ContainerException
* @throws ReflectionException
* @throws HttpServerException
*/
public function handle(EventInterface $event): void
{
/** @var Router $router Register HTTP routes */
$router = bean('httpRouter');
RouteRegister::registerRoutes($router);
// Register middleware
MiddlewareRegister::register();
}
}
这里使用了Swoft\Event\Annotation\Mapping\Listener注解，对应的事件为SwoftEvent::APP_INIT_COMPLETE。
按照上面的分析，这里会调用到AppInitCompleteListener的handle方法，获取httpRouter的Bean实例，注册http服务的路由信息和中间件。
到这里，我们大概清楚了EventProcessor这个模块的作用，注册了所有事件的回调。
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