See also: OATC Wiki Home





Date: March 9-12, 2009




Venue:Wallingford Software, Howbery Park, Wallingford, Oxfordshire, OX10 8BA, United Kingdom,




Participants:



Standa Vanecek, (chair), DHI (s.vanecek@dhi.cz)

Unknown User (jnh@dhigroup.com) Johan Hartnack , DHI

Adrian Harper, Wallingford Software (adrian.harper@wallingfordsoftware.com)

Stef Hummel, Deltares (stef.hummel@deltares.nl)

Unknown User (don) (Gena), Deltares (gennadii.donchyts@deltares.nl)



Apologies:



Jan Gregersen, LicTek (gregersen@lictek.dk)

Andrea Antonello, Universita` di Trento, (andrea.antonello@gmail.com)

Unknown User (onnoroos), Alterra (Onno.Roosenschoon@wur.nl)

Peter Schade, Bundesanstalt fuer Wasserbau, Germany (Peter.Schade@BAW.DE)

Jon Goodall, Univ South Carolina (goodall@engr.sc.edu)

Rob Knapen, Alterra (Rob.Knapen@wur.nl)

Peter Gijsbers, Deltares (Peter.Gijsbers@deltares.nl)




Documents:



http://www.openmi.org/

http://sourceforge.net/projects/openmi

wiki.openmi.org



Table of contents




Minutes




1. Minutes from previous OATC meeting



2. Maintenance and support



2.1 OpenMI 1.4.1 release



Two new issues have come to light

1) GetHashCode

2) Event check boxes (worked in 1.2, broken 1.4 onwards)

adrian will review these and decide whether to include in 1.4.1 release, delay to 1.4.2 or 2.0.0

Then do whatever required to release 1.4.1 ASAP




3. OpenMI 2.0 Issues



3.1 Oatc.OpenMI.Sdk.ModelWrapper





3.2 Remarks on Standard as result of Java review



From the Trento C# version I (Stef) created a java version, code only, no comments, which was reviewed by Rob. See trunk/OpenMI.Standard/src/javaFor2.0.

This led to some remarks, of which a few were "java only", but some of them reflected on the Standard in general. Items to be addressed at the next meeting:



    
	
  1. IDimension.equals() should be been renamed to IDimension.describesSameAs(), to be constistent with IValueDefinition.describesSameAs(), and to put emphasis on the fact the we are comparing dimensions from a "content point of view", and not implementing the language's Object.equals() function
	
      
		
    1. (thumbs up)
      2. 
	
    
	
    2. 
	
  2. Question: do we still want to have the hardcoded integer enumeration values in ElementType, DimensionBase, etc.? I think they originated from the time that we also wanted to describe these possible values in c and/or Fortran.
	
      
		
    1. (thumbs up)
      2. 
	
    
	
    3. 
	
  3. Question: what does isAvailable() mean in case of multiple consumers. Do all consumers need to have the same time(s)?
	
      
		
    1. (question) Leave in for now, review after more implementation, one suggestion of modification bool isAvailable(whosAsking);
      2. 
	
    
	
    4. 
	
  4. Question: Collection or Set instead of List for (In|Out)putExchangeItems in LC?
	
      
		
    1. (thumbs down) Leave as is, as definatly cannot use set as unimplemented in .NET currently.
      2. 
		
    2. (question) Gena: I will check if changing it to ICollection<> works fine.
      3. 
	
    
	
    5. 
	
  5. Question: Introduce IState instead of Object? This will emphasize the relation between IManageState and IPersistentState. Additional suggestion: IPersistentState extends IState.
    
(b.t.w: makePersistent / readPersistentState are wrong names, should be something like getAsByteStream)

    Gena will discuss with Rob
    
	
      
		
    1. (question) Unresolved at this time, if Rob can convinve Gena then we can (thumbs up). The suggestion is the following: Suggestion about changed to state management
      2. 
	
    
	
    6. 
	
  6. To be discussed: Introduce generics in IOutputItem.Values()? i.e. weakly typed via <T>
	
      
		
    1. (question) Gena will implement examples in the SDK, but not, for now, in the standard
      2. 
	
    
	
    7. 
	
  7. Remark: Working with providers/consumers, we should take care that such a circularity might give garbage collection problems

    Implementing IDisposable and removing item from Provider/Consumers there might solve the problem
    
	
	
    8. 
	
  8. Question: for Java, shall we use Observer/Observable for events? We then have to offer a base implementation comparable with the current IListener/IProvider.
	
      
		
    1. (thumbs up) accepted, Rob and Gina to investigation a suitable solution. The suggestion is the following: Suggestion about Java observer based event handling
      2. 
	
    
	
    9. 
	
  9. To be discussed: what exactly is returned by IOutputDecorater.Arguments()?

    Adrian suggested to have Provider there in the interface, then we can step to the previous decorators (if there are any) and get their arguments, and show them nicely grouped in the GUI.
    
	
      
		
    1. (thumbs up) resolved by other item on agenda
      2. 
	
    
	
    10. 





3.3 Suggestions for the states and possible transitions between the states of the ILinkableComponent






If component has Invalid status and we call Validate() - it may even call Update() on another components in order to validate itself.



New things:

(thumbs up) WaitingForData status

(thumbs up) Loop around Validate after each Update()

(thumbs up) Invalid status



Action Stef: will add these changes to the v2 Trunk




3.4 More suggestions on v2.0 changes






How IOutputItem.Values can be used, one possible way:






Please put comments here: Discussion on the possible use of IOutputItem.Values






We should have way in the decorator to trace it in the debugger, gui.






interface IOutputItemDecorator : IOutputItem
{
   IArgument[] Arguments { get; }
   IOutputItem DecoratedOutputItem { get; set; }
}







Internally decorator may connect output item which is being decorated to internal IInputItem which has exactly the same structure as output item being decorated. Then it can transform values into required output structure, which can be determined by the Arguments or consuming input item(s).



Decorator of the IOutputItem, current version introduced before meeting 22



Note, that current implementation actually does not include IInputItem inside decorator implementation, so, the question arises: where output exchange item being decorated is connected to?. It should be something compatible with it (the same element set, time set, value definition).





Decorator as a component embedded into linkable component


It can be implemented in this way using current standard, however those internal decorating components are not visible using current standard. It would be possible to access them if the following property will be added:


public interface ILinkableComponent
{
    IList<ILinkableComponent> Components { get; } 
}







Empty Sets in Input items / ElementSet changing in time


Using empty ElementSet or TimeSet in the InputItem were discussed. This discussion open problems in using of the ElementSets changing in time. See Empty Sets in the Input Items - Element set changing in time





Use Case: analytical function



See Implementation of the AnalyticalFunction use case for unit tests showing different ways to implement components



5. OATC Procedures




6. Miscellaneous issues



7. Tasks and unresolved issues



All tasks are handled by sourceForge. GOTO: OpenMI Tasks on source forge



8. Any other business









See goodall_poster.pdf







Discussions about Times in OpenMI



Please put comments here: Discussion on times, to use or not to use standard .NET times