Added cleaner parent factory interface

Can now just specify an entire factory and not just its new function

Author: AndrewBurian

README.md

@@ -45,7 +45,7 @@ lotteryStream.Broadcast(everyoneLosesEvent)
 ```
 
 ### Auto subscribe certain routes to topics
-`Stream` implements an `http.Handler` but by default just registers clients for broadcasts. 
+`Stream` implements an `http.Handler` but by default just registers clients for broadcasts.
 
 Use `TopicHandler` to create another handler for that stream that will subscribe clients to topics as well as broadcasts.
 ```go
@@ -94,7 +94,7 @@ func ServeHTTP(w http.ResponseWriter, r *http.Request) {
     http.Error(...)
     return
   }
-  
+
   client.Wait()
 }
 ```
@@ -149,7 +149,7 @@ typeFact := &eventsource.EventTypeFactory{
 // then with incrementing ID's
 idFact := &eventsource.EventIdFactory{
   Next:    0,
-  NewFunc: typeFact.New,
+  NewFact: typeFact,
 }
 
 // then generate as many events as you want with

event_factory.go

@@ -14,7 +14,10 @@ type EventFactory interface {
 // sequential ID fields.
 // If NewFunc is set, the factory uses it to create events before setting
 // their IDs
+// If NewFunc is not set, NewFact will be used. If neither is set, a new
+// event is created from scratch
 type EventIdFactory struct {
+	NewFact EventFactory
 	NewFunc func() *Event
 	Next    uint64
 }
@@ -24,6 +27,8 @@ func (f *EventIdFactory) New() *Event {
 	var e *Event
 	if f.NewFunc != nil {
 		e = f.NewFunc()
+	} else if f.NewFact != nil {
+		e = f.NewFact.New()
 	} else {
 		e = &Event{}
 	}
@@ -35,17 +40,22 @@ func (f *EventIdFactory) New() *Event {
 
 // EventTypeFactory creates events of a specific type
 type EventTypeFactory struct {
+	NewFact EventFactory
 	NewFunc func() *Event
 	Type    string
 }
 
 // New creates an event with the event type set
 // If NewFunc is set, the factory uses it to create events before setting
 // their event types
+// If NewFunc is not set, NewFact will be used. If neither is set, a new
+// event is created from scratch
 func (f *EventTypeFactory) New() *Event {
 	var e *Event
 	if f.NewFunc != nil {
 		e = f.NewFunc()
+	} else if f.NewFact != nil {
+		e = f.NewFact.New()
 	} else {
 		e = &Event{}
 	}