<html>
<head>
<meta content="text/html; charset=windows-1252"
http-equiv="Content-Type">
</head>
<body text="#000000" bgcolor="#FFFFFF">
<br>
<div class="moz-cite-prefix">On 12/17/2014 05:49 PM, Antoine
Sabot-Durand wrote:<br>
</div>
<blockquote
cite="mid:1EFACDFC-267C-4F36-8B0D-22B44FF43B6A@sabot-durand.net"
type="cite">
<meta http-equiv="Content-Type" content="text/html;
charset=windows-1252">
<div class="">Ok guys,</div>
<div class=""><br class="">
</div>
<div class="">Let’s do it again. I didn’t say we have to forbid
the mutability I said we have at least to explicitly write that
it’s mutable</div>
</blockquote>
Agreed.<br>
<blockquote
cite="mid:1EFACDFC-267C-4F36-8B0D-22B44FF43B6A@sabot-durand.net"
type="cite">
<div class=""> and seriously think of having it immutable for
event fired asynchronously.</div>
</blockquote>
I agree that we should have a discussion about pros/cons. From what
I saw working on a fireAsync prototype to me the possible benefits
of allowing immutable events only are not worth the limitations.<br>
<blockquote
cite="mid:1EFACDFC-267C-4F36-8B0D-22B44FF43B6A@sabot-durand.net"
type="cite">
<div class=""><br class="">
</div>
<div class="">
<blockquote type="cite" class="">(Pete) I don’t think it’s
specified. As objects are, by default in Java, mutable, I
would assume that payloads are implicitly mutable.</blockquote>
</div>
<div class=""><br class="">
</div>
<div class="">Sorry @Pete I don’t agree with your point. Yes, in
Java object are mutable but firing an event is not a standard
Java feature : you send your object to a black box and let this
box dispatch your object to listeners transforming one call to
multiple call : it’s far from standard Java rules. Even if it’s
not written it’s an observer pattern and there are people out
there thinking that introducing mutability in observer is an
anti-pattern since some listener will receive a different
payload than the one that was sent to them. </div>
<div class="">It’s like making a method call and having no
guarantee that the parameter received in the callee has the same
value that in the caller...</div>
<div class="">I won’t start discussion on bad practice or anti
pattern as I also use mutability in event but there as much
reason for user to assume their payload will be mutable than the
other way around.</div>
<div class="">I can assure you that when I give a talk on CDI,
this payload mutability is often a surprise for attendees...</div>
<div class=""><br class="">
</div>
<div class="">
<blockquote type="cite" class=""><span style="font-family:
Menlo-Regular; font-size: 11px;" class="">(Romain) why isn't
it portable?</span></blockquote>
</div>
<div class=""><br class="">
</div>
<div class="">So yes @Romain it’s not portable (in theory of
course, since both implementations support mutability). Someone
could write a CDI implementation with event payload immutability
without any issue with the spec and TCK.</div>
<div class=""><br class="">
</div>
<div class="">Most of you are so dependent of this feature that
you only reacted to the idea or forbidding it (which wasn’t the
content of my mail) ;). So we all agree that it’s an important
feature. Therefore what’s the issue to specify this mutability
and add TCK test for it ?</div>
<div class=""><br class="">
</div>
<div class="">Now I don’t deal with that subject for nothing, we
are planning to introduce Async events. I think that it’ll bring
extra complexity if we support mutability in async events. And
even if I’m wrong and we finally go for mutability in async
events, this will lead to possible side effect (lock) that could
have impact on perf, so it should be explicitly written IMO.</div>
<div class=""><br class="">
</div>
<div class="">Antoine</div>
<div class=""><br class="">
</div>
<div class=""><br class="">
</div>
<div class=""><br class="">
</div>
<div class=""><br class="">
</div>
<div class=""><br class="">
</div>
<div class=""><br class="">
</div>
<div class=""><br class="">
</div>
<br>
<fieldset class="mimeAttachmentHeader"></fieldset>
<br>
<pre wrap="">_______________________________________________
cdi-dev mailing list
<a class="moz-txt-link-abbreviated" href="mailto:cdi-dev@lists.jboss.org">cdi-dev@lists.jboss.org</a>
<a class="moz-txt-link-freetext" href="https://lists.jboss.org/mailman/listinfo/cdi-dev">https://lists.jboss.org/mailman/listinfo/cdi-dev</a>
Note that for all code provided on this list, the provider licenses the code under the Apache License, Version 2 (<a class="moz-txt-link-freetext" href="http://www.apache.org/licenses/LICENSE-2.0.html">http://www.apache.org/licenses/LICENSE-2.0.html</a>). For all other ideas provided on this list, the provider waives all patent and other intellectual property rights inherent in such information.</pre>
</blockquote>
<br>
</body>
</html>