10 Nov
2010
10 Nov
'10
9:57 a.m.
Hi Stefan,
On Nov 10, 2010, at 9:08 AM, Stefan abageru wrote:
Hi devs !
I thought about adding some changes in Events and Activity Stream.
First of all, I want to remove all the listeners from Activity Stream
and make this class listen to AllEvent, making it capable of cathcing
all events that occur in the wiki (and this way, when adding a new
event, you wouldn't need any modifications to this class in order to
catch it).
How do you filter events to process? If you don't how would you display for example
view events or internal events such as component manager descriptor added/removed event,
or the new event being added by Anca for the XAR import?
Secondly, I would like to modify onEvent function in
the class so that
it uses the simpleClassName of the event occurred in order to log the
event (the eventType would be this simpleClassName...for example
DocumentSavedEvent, AnnotationAddedEvent and so on).
I don't agree with this, or I don't understand it. You get the Event object so you
can easily get the simple class name by calling event.getClass().getSimpleClassName().
And thirdly i thought about adding one field in
AbstractFilterableEvent
called /identifier/ and make all events extend directly this class.
Again I don't agree. A notion of event identifier is not linked to a Filterable event
IMO but to the Event class itself.
And
that /identifier/ would be used in a different way by the events
themselves. But it would be used to retrieve infos about that events.
And so, when logging an event, we could use classname + identifier.
For example
AnnotationAddedEvent + "This is my annotation" .
CommentAddedEvent + "This is my comment" or the number of the comment.
I don't quite agree. If it's supposed to be an identifier it must be unique and
leaving the unicity to the user will not guarantee it's unique. I'm not sure what
you want to do:
1) Be able to differentiate 2 events. For what reason?
2) Be able to have some description of the events. Again for what reason?
Now if you need extra data, this is already taken into account in the onEvent method:
void onEvent(Event event, Object source, Object data);
The data parameter is there to pass extra data.
The way to use it is to create compound objects if you need to pass several data.
However for easiness of use, I'd agree to transform the signature into:
void onEvent(Event event, Object source, Object... data);
All that said, we have a small issue in that the listener of events need to know what type
of data get passed and thus emitter and listeners must be in sync. Thus a generic listener
will always have a problem since it won't know the type of objects it receives (since
they're different for each event). Thus for me, when you have a generic listener you
also need an EventActionHandler that needs to be registered against the generic listener
so that it know what to do with the extra data passed.
How would you handle anonymous events in the Activity Stream (AS) listener? BTW what
actions do you need to do with received events in the AS?
Thanks
-Vincent