Re: [wsbpel] Issue 229 - compensate activity naming

[Rania Khalaf <rkhalaf@watson.ibm.com>]

Hi guys,

I just saw that issue 217 is actually exactly about the naming of 
<compensate/> vs <compensate scope=""/> so we can move that discussion 
there (and get some more context from it's email thread) and close on 
229  ?

regards,
rania


Alex Yiu wrote:
> 
> Hi Alexandre,
> 
> *[A]*
> For an XML-savy person or BPEL-savy person, it would not be too 
> difficult to distinguish between <compensate/> and <compensate 
> scope="X"/>. 
> 
> But, if one tries to talk about the difference to a customer or a 
> consultant over the phone, then one may find it difficult. For example, 
> I need to say "...  _a compensate activity without any scope attribute_ 
> ..." to orally describe <compensate/>.   ;-)
> 
> And, yes, compensation in BPEL is not a trvial concept to explain. But, 
> let us have a different element name. So, it would be easier for us to 
> explain to our audience. :-)
> 
> *[B]*
> More unfortunately, even our current spec is also messed up. When we use 
> <compensate/> ambigously, we sometimes mean "_a compensate activity 
> without any scope attribute_" sometimes just a general compensate activity.
> 
> E.g.:
> *13.5. Event Handlers*
> 
>     "... invocation of compensation handlers using the <compensate/>
>     activity is not permitted. As stated earlier, the <compensate/>
>     activity can only be used in fault and compensation handlers. ... "
> 
> 
> That actually refers to a general compensate activity.
> 
> To avoid further confusion / mistake in our spec editing or spec 
> reading, I really still think we should move to another activity name 
> for <compensate/> for default compensation.
> 
> 
> *[C]*
> Another example of these naming pattern is <throw> vs <rethrow>.  The 
> syntax of the original proposal for "rethrow" is: <throw /> without any 
> attribute. I made an amendment to rename it to <rethrow>. I think that 
> really helps us in our spec text to describe the difference between 
> throw and rethrow. If we had collapsed both features under the same 
> element name, we would have a similar problem in spec text.
> 
> *[D]*
> I do agree with your concern about "inner" may imply existence of 
> "outer". So I would prefer "compensateChildScopes" or "compensateChildren".
> 
> *[E]
> *Assume we are going for the renaming. We really should use it as an 
> opportunity to clean the spec text at the same time. That is:
> 
> "a compensate activity" means both variants of compensation <compensate 
> scope="X" /> and <compensateChildScopes/>.
> "a <compensate> activity" means <compensate scope="X" />
> "a <compensateChildScopes> activity" means of course 
> <compensateChildScopes/>.
> 
> 
> I really hope the current spec text in Section 13.5 convinces people 
> that current activity naming could cause some confusion.
> 
> 
> Thanks!
> 
> 
> Regards,
> Alex Yiu
> 
> 
> 
> aalves@bea.com wrote:
> 
>>Hi,  
>>
>>This is a minor observation, but I don't find it that confusing to differentiate between <compensate/> and <compensate scope="X"/>.   
>>
>>I actually think it makes sense to have the same Xml element relate to both forms of compensation, as, after-all, both do deal with compensation of their inner scopes, the latter selectively.  
>>
>>Compensation is a tricky feature to explain nonetheless, it seems to me that having a more descriptive name won't help that much, hence I am in favor of keeping the simplicity of the single compensate name.  
>>
>>For example, we don't have a <receiveInOnly/>, <receiveInOut/> instead of just <receive/>. Also <compensateInner/> seems to indicate that there is a <compensateOuter/>.  
>>
>>Anyway, just my opinion, either way we go is fine with me.  
>>
>>Sincerely, 
>>
>