See also: OATC Wiki Home

Date: April 21.4 - 23.4, 2009
Venue:DHI, Hørsholm, Agern Allé 5, Denmark

Participants:

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

3. OpenMI 2.0 Issues

3.2 Pending Remarks on Standard as result of Java review

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. # Question: what does isAvailable() mean in case of multiple consumers. Do all consumers need to have the same time(s)?
   1. Leave in for now, review after more implementation, one suggestion of modification bool isAvailable(whosAsking);
2. Question: Collection or Set instead of List for (In|Out)putExchangeItems in LC?
   1. Gena: I will check if changing it to ICollection<> works fine.
3. 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. Unresolved at this time, if Rob can convinve Gena then we can . The suggestion is the following: Suggestion about changed to state management
4. To be discussed: Introduce generics in IOutputItem.Values()? i.e. weakly typed via <T>
   1. Gena will implement examples in the SDK, but not, for now, in the standard
5. 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

   • Point noted, no aggreement as to solution

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.

3.4 More suggestions on v2.0 changes

• Move IsAvailable to IExchangeItem. Is it only for a thread-safety? If yes than see also ICollection.IsSynchronized

  Stef: The question is confusing, the actual issue is that we should distinguish between IsAvailable and IsValid.
  We are now realized that there is a difference between IsAvailable (only for output item, means it is for consumers) IsValid (probably for IExchangeItem, meaning if item is valid in the context of current component, maybe updated during Validate() call)?

• Move Values { get; set; } to IExchangeItem

  Stef: alternative would be to add get to the IInputExchangeItem

  • get accepted,
  • set review later
• Change ID to Id - .NET Style Guidelines, FxCop

• Add params keyword to IArguments[] args parameter in Initialize(IArgument[] args).

  •  Adrian review, if happy then ...
• Change "string Validate()" to "bool IsValid(IExchangeItem item)"

  Gena: probably the second one is not needed if we will have IsValid in IExchangeItem.
  string return type in the Validate() has to be changed to void.

  • Requires review after more experiance with implementing standard

• Add "params IExchangeItem[] items" argument to Update() in order to specify explicitly what should be updated.

  • as IOutputItem, maybe later generalise to IExchangeItem i.e. allow IInputItem
• Remove AddConsumer/RemoveConsumer and use BindingList in the implementation instead to listen to IOutputItem.Consumer.Add() / Remove()
  • Not critical yet, so leave for now, review again later
• Temporal ==(rename)==> TimeSet and add Durations, TimeZone properties to it (see also changes from Rob in Java version)
  • Rename
  • Requires discussion in lator meetings
• When we get loops in the compositions - we have to tell which component will be first! (WHAT SHOULD WE DO IN THIS SITUATAION?) Relevant when implementing the Runner process in GUI
• Replace all ITime, ITimeStamp, ITimeSpan by: System.DateTime, System.TimeSpan. Should be straightforward. For components working in Julian only time in FORTRAN CalendarConverter can be used. But for .NET all nice features of the .NET date time, time span will be available, e.g. DateTime.AddDays(int), DateTime.AddHours(int), time1 > time2, time1.AddDays(1) > DateTime.Now, and so on.
  Seems to be very straightforward and simple to implement.**
  •  
• Change XYPoint+XYZPoint, ZYPolyline+XYZPolyline => Point, Polyline (make it look more like OGC entities)
  • Review OGC methods to see how we know when a Z coordinate exists?
• Split IIdentity into class IIdentifiable { long Id { get; set; } } and class IDescribable { string Caption { get; set; } string Description { get; set; } }
  • Splitting interfaces
  • Make various interfaces derive from IIdentifiable, to review
• Do we need a TimeHorizon in the ILinkableComponent ? Seems to be useless since we have ITemporal
• IArgument needs a mechanism for identifying the type of argument e.g. File, Path, int double etc Very usful for providing customised GUI functionality
  • Adrian to come up with proposal for next meeting
• (Using empty Temporal and ElementSet in the Input items
• Changing of the ElementSet during the time and different Times (steps) for different Elements
  • For the Time can be probably solved by missing values

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

• Make IOutputDecorator to be:

interface IDecorator : IOutputItem, IInputItem
{
   IArgument[] Arguments { get; }
}

5. OATC Procedures

6. www.OpenMI.org and wiki.OpenMI.org

7. Miscellaneous issues

8. Tasks and unresolved issues

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

9. Any other business

• Check ideas mentioned in the poster of Jon Goodall - see meeting 22