RE: [xmlblaster] Demo: Adding client specific properties to the QoS on publishing

["David Hooker" <dhooker at btrade.com>]

Sorry, one last question.... are these properties available in the
UpdateQoS?  The REQ doesn't mention UpdateQoS.  If it's not in there, it
should be.

-----Original Message-----
From: owner-xmlblaster at server.xmlBlaster.org
[mailto:owner-xmlblaster at server.xmlBlaster.org] On Behalf Of Michele
Laghi
Sent: Monday, October 13, 2003 2:57 PM
To: xmlblaster at server.xmlblaster.org
Subject: Re: [xmlblaster] Demo: Adding client specific properties to the
QoS on publishing


Hi David,
technically speaking there is little difference. However sending it in 
the key is a hack which of course works fine in the most of the cases 
but it is uggly since the key:

- is supposed to be invariant and
- is put in the big dom tree when the topic is created.

One potentially dangerous side effect could be the following. Suppose 
you were putting this information into the key:

Client A sends its first message to the 'flowers' topic:
<key oid='flowers'>
   ...
   <clientProperty name='color'>red</clientProperty>
   ...
</key>

Client B sends its first one *without* a 'color' specification:

<key oid='flowers'>
   ...
   <!-- *no color specified in this entry* -->
   ...
</key>

Client C subscribes with the following xpath query:
//clientProperty[ at name='color']

If A published before B the result would be that C would become *all* 
updates, not only the ones with the color specified. If B would publish 
before A, C would *never* become an update.

Regards
Michele


David Hooker wrote:
> What's the benefit of using these properties instead of the clientTags
> in the UpdateKey?
> 
> -----Original Message-----
> From: owner-xmlblaster at server.xmlBlaster.org
> [mailto:owner-xmlblaster at server.xmlBlaster.org] On Behalf Of Michele
> Laghi
> Sent: Monday, October 13, 2003 11:51 AM
> To: xmlblaster at server.xmlblaster.org
> Subject: Re: [xmlblaster] Demo: Adding client specific properties to
the
> QoS on publishing
> 
> 
> Hi David,
> The requirement specifying this is
>
http://www.xmlBlaster.org/xmlBlaster/doc/requirements/engine.qos.clientP
> roperty.html
> 
> Michele
> 
> 
> David Hooker wrote:
> 
>>Is there a REQ I can look at for this?
>>
>>-----Original Message-----
>>From: owner-xmlblaster at server.xmlBlaster.org
>>[mailto:owner-xmlblaster at server.xmlBlaster.org] On Behalf Of Marcel
> 
> Ruff
> 
>>Sent: Sunday, October 12, 2003 3:25 PM
>>To: xmlblaster
>>Subject: [xmlblaster] Demo: Adding client specific properties to the
> 
> QoS
> 
>>on publishing
>>
>>
>>Hi,
>>
>>Michele has added support to add client specific properties
>>to the publish QoS, these properties will be delivered
>>to subscribers in the QoS, to play with it you can use our
>>Java demo publisher like this:
>>
>>  java javaclients.HelloWorldPublish -numPublish 50
>>                       -clientProperty[transactionId] 0x23345
>>                       -clientProperty[myName] jack
>>
>>would add the properties to the publish QoS like this:
>>
>>  <clientProperty name='transactionId'>0x23345</clientProperty>
>>  <clientProperty name='myName'>jack</clientProperty>
>>
>>
>>You can look at the received QoS with a subscriber:
>>
>>  java javaclients.HelloWorldSubscribe
>>
>>enjoy
>>
>>Marcel
>>
> 
> 
> 


-- 
Michele Laghi
mailto:laghi at swissinfo.org
tel. +46 8 7492952 / mob. +46 70 4103964
http://eclettic.tripod.com
http://www.xmlBlaster.org