eventbus: refactoring; add unsubscribe_method and unsubscribe_receiver (#9443)

vlib/eventbus/eventbus.v

@@ -18,10 +18,10 @@ mut:
 }
 
 struct EventHandler {
-	name string
-	handler EventHandlerFn
+	name     string
+	handler  EventHandlerFn
 	receiver voidptr = voidptr(0)
-	once bool
+	once     bool
 }
 
 pub struct EventBus {
@@ -35,11 +35,7 @@ pub fn new() &EventBus {
 	registry := &Registry{
 		events: []
 	}
-	return &EventBus{
-		registry,&Publisher{
-			registry},&Subscriber{
-			registry}
-	}
+	return &EventBus{registry, &Publisher{registry}, &Subscriber{registry}}
 }
 
 // EventBus Methods
@@ -59,43 +55,46 @@ pub fn (eb &EventBus) has_subscriber(name string) bool {
 
 // Publisher Methods
 fn (mut pb Publisher) publish(name string, sender voidptr, args voidptr) {
-	for i, event in pb.registry.events {
+	for event in pb.registry.events {
 		if event.name == name {
-			if event.once {
-				pb.registry.events.delete(i)
-			}
 			event.handler(event.receiver, args, sender)
 		}
 	}
+	pb.registry.events = pb.registry.events.filter(!(it.name == name && it.once))
 }
 
 fn (mut p Publisher) clear_all() {
-	if p.registry.events.len == 0 {
-		return
-	}
-	for i := p.registry.events.len - 1; i >= 0; i-- {
-		p.registry.events.delete(i)
-	}
+	p.registry.events.clear()
 }
 
 // Subscriber Methods
 pub fn (mut s Subscriber) subscribe(name string, handler EventHandlerFn) {
-	s.registry.events << EventHandler {
+	s.registry.events << EventHandler{
 		name: name
 		handler: handler
 	}
 }
 
 pub fn (mut s Subscriber) subscribe_method(name string, handler EventHandlerFn, receiver voidptr) {
-	s.registry.events << EventHandler {
+	s.registry.events << EventHandler{
 		name: name
 		handler: handler
 		receiver: receiver
 	}
 }
 
+// unsubscribe_method unsubscribe a receiver for only one method 
+pub fn (mut s Subscriber) unsubscribe_method(name string, receiver voidptr) {
+	s.registry.events = s.registry.events.filter(!(it.name == name && it.receiver == receiver))
+}
+
+// unsubscribe_receiver unsubscribes a receiver from all events
+pub fn (mut s Subscriber) unsubscribe_receiver(receiver voidptr) {
+	s.registry.events = s.registry.events.filter(it.receiver != receiver)
+}
+
 pub fn (mut s Subscriber) subscribe_once(name string, handler EventHandlerFn) {
-	s.registry.events << EventHandler {
+	s.registry.events << EventHandler{
 		name: name
 		handler: handler
 		once: true
@@ -106,23 +105,19 @@ pub fn (s &Subscriber) is_subscribed(name string) bool {
 	return s.registry.check_subscriber(name)
 }
 
+
+
+// is_subscribed_method checks whether a receiver was already subscribed for any events
+pub fn (s &Subscriber) is_subscribed_method(name string, receiver voidptr) bool {
+	return s.registry.events.any(it.name == name && it.receiver == receiver)
+}
+
 pub fn (mut s Subscriber) unsubscribe(name string, handler EventHandlerFn) {
 	// v := voidptr(handler)
-	for i, event in s.registry.events {
-		if event.name == name {
-			if event.handler == handler {
-				s.registry.events.delete(i)
-			}
-		}
-	}
+	s.registry.events = s.registry.events.filter(!(it.name == name && it.handler == handler))
 }
 
 // Registry Methods
 fn (r &Registry) check_subscriber(name string) bool {
-	for event in r.events {
-		if event.name == name {
-			return true
-		}
-	}
-	return false
+	return r.events.any(it.name == name)
 }

vlib/eventbus/eventbus_test.v

@@ -4,6 +4,10 @@ struct EventData {
 	data string
 }
 
+struct FakeReceiver {
+	ok bool
+}
+
 fn test_eventbus() {
 	ev_data := &EventData{'hello'}
 	mut eb := eventbus.new()
@@ -21,8 +25,85 @@ fn test_eventbus() {
 	assert !eb.subscriber.is_subscribed('on_test')
 }
 
+fn test_subscribe_method() {
+	// Does not really test subscribe_method idinvidually though
+	// given
+	mut eb := eventbus.new()
+	r := FakeReceiver{}
+
+	assert !eb.subscriber.is_subscribed_method('on_test_with_receiver', r)
+	// when
+	eb.subscriber.subscribe_method('on_test_with_receiver', on_test_with_receiver, r)
+
+	// then
+	assert eb.subscriber.is_subscribed_method('on_test_with_receiver', r)
+}
+
+fn test_unsubscribe_method() {
+	// given
+	mut eb := eventbus.new()
+	r := FakeReceiver{}
+	r2 := FakeReceiver{}
+
+	// when
+	eb.subscriber.subscribe_method('on_test_with_receiver', on_test_with_receiver, r)
+	eb.subscriber.subscribe_method('on_test_with_receiver', on_test_with_receiver, r2)
+	eb.subscriber.unsubscribe_method('on_test_with_receiver', r)
+
+	// then
+	assert !eb.subscriber.is_subscribed_method('on_test_with_receiver', r)
+	assert eb.subscriber.is_subscribed_method('on_test_with_receiver', r2)
+}
+
+fn test_publish() {
+	// given
+	ev_data := &EventData{'hello'}
+	mut eb := eventbus.new()
+
+	// when
+	eb.subscriber.subscribe_once('on_test', on_test)
+	eb.subscriber.subscribe_once('on_test', on_test)
+	eb.publish('on_test', eb, ev_data)
+
+	// then
+	assert !eb.subscriber.is_subscribed('on_test')
+}
+
+fn test_publish_with_receiver() {
+	// given
+	mut eb := eventbus.new()
+	ev_data := &EventData{'hello'}
+	r := FakeReceiver{}
+
+	// when
+	eb.subscriber.subscribe_method('on_test_with_receiver', on_test_with_receiver, r)
+	eb.publish('on_test_with_receiver', eb, ev_data)
+
+	// then asserts are in on_test_with_receiver, don't know how to be sure
+	// that it has been properly called...
+}
+
+fn test_unsubscribe_reveiver() {
+	// given
+	mut eb := eventbus.new()
+	r := &FakeReceiver{}
+
+	// when
+	eb.subscriber.subscribe_method('on_test_with_receiver', on_test_with_receiver, r)
+	eb.subscriber.subscribe_method('on_test', on_test, r)
+	eb.subscriber.unsubscribe_receiver(r)
+	assert !eb.subscriber.is_subscribed_method('on_test_with_receiver', r)
+	assert !eb.subscriber.is_subscribed_method('on_test', r)
+}
+
 fn on_test(receiver voidptr, ev &EventData, sender voidptr) {
 	assert receiver == 0
 	assert sender != 0
 	assert ev.data == 'hello'
 }
+
+fn on_test_with_receiver(receiver &FakeReceiver, ev &EventData, sender voidptr) {
+	assert receiver.ok == false
+	assert sender != 0
+	assert ev.data == 'hello'
+}