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REQUIREMENT

engine.qos.subscribe.initialUpdate

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Type NEW
Priority LOW
Status CLOSED
Topic On subscribe you can prevent the initial message update for existing messages.
Des
cription

Imagine a message exists already in xmlBlaster. If you subscribe for this message you will receive an initial update for this existing message (default behavior). In some cases you want to prevent this to only receive an update when a new message is published after subscription.

If you set the subscribe QoS to 

<qos> 
   ...
   <initialUpdate>false</initialUpdate>
</qos>

you won't receive the initial update triggered by the subscription.

Example
Java 
      
import org.xmlBlaster.client.qos.SubscribeQos;

...

try {
   SubscribeQos sq = new SubscribeQos(glob);

   sq.setWantInitialUpdate(false);

   String subId = con.subscribe("<key oid='NOTAM'/>, sq.toXml());
}
catch (Exception e) {
   ...
}
...
Configure

NOTE: Configuration parameters are specified on command line (-someValue 17) or in the xmlBlaster.properties file (someValue=17). See requirement "util.property" for details.
Columns named Impl tells you if the feature is implemented.
Columns named Hot tells you if the configuration is changeable in hot operation.

See API org.xmlBlaster.client.qos.SubscribeQos
See TEST org.xmlBlaster.test.qos.TestSubNoInitial

This page is generated from the requirement XML file xmlBlaster/doc/requirements/engine.qos.subscribe.initialUpdate.xml

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