Fill parameters in LCDS Assembler methods

Last few days we spent debugging some nasty bug in the code that uses LiveCycle managed collections. We were adding/removing items to/from collections on the server side. We saw that server sent a message to the client, client did receive the message, but then it ignored it and didn't update the collection (data grid). After digging into the client side logs we found the reason of such a misbehaviour.

If you have two destinations that share the same channel

<service id="data-service" class="flex.data.DataService">
   <destination id="MyFirstDestination">
       <channels>
           <channel ref="my-rtmp-channel"/>
       </channels>
       <properties>
           <source>example.MyFirstAssembler</source>
       </properties>
   </destination>
   <destination id="MySecondDestination">
       <channels>
           <channel ref="my-rtmp-channel"/>
       </channels>
       <properties>
           <source>example.MySecondAssembler</source>
       </properties>
   </destination>
</service>

LCDS uses fillParameters as a key in the managed collections cache. That means fillParameters must be immutable.

public class MyFirstAssembler extends flex.data.assemblers.AbstractAssembler {

  @Override
  public int refreshFill(List fillParameters, Object newItem, boolean isCreate, Object oldItem, List changes) {
    // Never change fillParameters!
  }

  @Override
  public Collection fill(List fillParameters) {
    // Never change fillParameters!
  }
}

Adobe documentation says nothing about this, so keep this rule in mind when working with LCDS managed collections.

Resources

• Flex log viewer