Zend SharedEventManager attaching custom target - events

Question

I'm playing with SharedEventManager
here is a working portion of code :
public function init(ModuleManager $moduleManager) {
echo("<H1>LISTENER</H1>");
$eventManager = $moduleManager->getEventManager();
$sharedEventManager=$eventManager->getSharedManager();
// attach a listener
$sharedEventManager->attach('*','do', function ($e) {
echo("<H4>Message receveid</H4>");
echo("<p>name={$e->getName()}<p>");
echo("<p>Target {$e->getTarget()}</p>");
echo("<p>param1={$e->getParams()['param1']}</p>");
});
// sending event
// set params
$params = ['param1' => 'value of param1'];
// way 1 : works...
$eventManager->trigger('do', 'CUSTOM_IDENTIFIER', $params);
// way 2 : works too
$event1=new \Zend\EventManager\Event('do', 'CUSTOM_IDENTIFIER', $params);
$eventManager->triggerEvent($event1);
}
and the output is ok :
LISTENER
Message receveid
name=do
Target CUSTOM_IDENTIFIER
param1=value of param1
Message receveid
name=do
Target CUSTOM_IDENTIFIER
param1=value of param1
so...
$sharedEventManager->attach('*','do', function ($e) ...
attach all targets *, for 'do' event name
it works...
A)
$sharedEventManager->attach('CUSTOM_IDENTIFIER','do', function ($e) ...
it doesn't work. ...i mean : no output , the message is not handled,
why ??
B)
$sharedEventManager->attach('CUSTOM_IDENTIFIER','*', function ($e) ...
it doesn't work. ...i mean : no output , the message is not handled,
why ??
Question : it is possible to attach events but only for CUSTOM_IDENTIFIER target without using * ?

Answer 1

Looking at your code, you are mixing Event's target and SharedEventManager's identifiers.
The correct version of your code, with correct names, is:
public function init(ModuleManager $moduleManager) {
echo("<H1>LISTENER</H1>");
$eventManager = $moduleManager->getEventManager();
$sharedEventManager = $eventManager->getSharedManager();
// attach a listener
$identifier = '*'; // Use all identifiers
$eventName = 'do';
$sharedEventManager->attach($identifier, $eventName, function ($e) {
echo '<p>Event received, <b>name:</b> "'.$e->getName().'", <b>Target:</b> '.$e->getTarget().'</p>';
});
// Sending event
$eventManager->trigger('do', 'CUSTOM_TARGET');
$eventManager->triggerEvent(new \Zend\EventManager\Event('do', 'CUSTOM_TARGET_NEW_EVENT'));
}
Which gives the following result:
LISTENER
Event received, name: "do", Target: CUSTOM_TARGET
Event received, name: "do", Target: CUSTOM_TARGET_NEW_EVENT
You must set the identifier to the EventManager, otherwise your CUSTOM_IDENTIFIER won't be used when the event will be triggered.
public function init(ModuleManager $moduleManager) {
echo("<H1>LISTENER</H1>");
$eventManager = $moduleManager->getEventManager();
$sharedEventManager = $eventManager->getSharedManager();
// Attach listener to all identifiers
$identifier = '*'; // Use all identifiers
$eventName = 'do';
$sharedEventManager->attach($identifier, $eventName, function ($e) {
echo '<p>ALL identifier, Event received, <b>name:</b> "'.$e->getName().'", <b>Target:</b> '.$e->getTarget().'</p>';
});
// Attach listener to custom identifier
$customIdentifier = 'MY_CUSTOM_IDENTIFIER'; // Use all identifiers
$sharedEventManager->attach($customIdentifier, $eventName, function ($e) {
echo '<p>Custom identifier, Event received, <b>name:</b> "'.$e->getName().'", <b>Target:</b> '.$e->getTarget().'</p>';
});
// Sending event
$eventManager->trigger('do', 'CUSTOM_TARGET');
$eventManager->triggerEvent(new \Zend\EventManager\Event('do', 'CUSTOM_TARGET_NEW_EVENT'));
$eventManager->addIdentifiers(['MY_CUSTOM_IDENTIFIER']);
$eventManager->trigger('do', 'CUSTOM_TARGET_CUSTOM_IDENTIFIER');
$eventManager->triggerEvent(new \Zend\EventManager\Event('do', 'CUSTOM_TARGET_CUSTOM_IDENTIFIER_NEW_EVENT'));
}
The result is:
LISTENER
ALL identifier, Event received, name: "do", Target: CUSTOM_TARGET
ALL identifier, Event received, name: "do", Target: CUSTOM_TARGET_NEW_EVENT
Custom identifier, Event received, name: "do", Target: CUSTOM_TARGET_CUSTOM_IDENTIFIER
ALL identifier, Event received, name: "do", Target: CUSTOM_TARGET_CUSTOM_IDENTIFIER
Custom identifier, Event received, name: "do", Target: CUSTOM_TARGET_CUSTOM_IDENTIFIER_NEW_EVENT
ALL identifier, Event received, name: "do", Target: CUSTOM_TARGET_CUSTOM_IDENTIFIER_NEW_EVENT
As you can see, the identifier * catches all events (therefore, the 4 lines of ALL identifier), whilst there are only 2 lines for the custom identifier.
Obviously, it'd be better to use a better (and more comprehensible) custom identifier, such as a class name, or an interface.
Hope this will help you