RE: [flexcoders] Flex 2 DS shared Managed Objects question

[Jeff Vroom]

Answers inline:   From: flexcoders@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of thunderstumpgesatwork Sent: Friday, August 04, 2006 8:04 AM To: flexcoders@yahoogroups.com Subject: [flexcoders] Flex 2 DS shared Managed Objects question   I'm using Data Services with Managed Objects and the Hibernate Assembler. I have a question regarding updating a shared managed object through one managed object, and having that update be reflected in another managed object. Should this work? I the most simple case, lets say I have a managed object A, that when fetched has a collection of other managed objects B. If I add a new managed object B, and save it directly through it's DataService, shouldn't A refresh its collection of B objects? When you are using an association property, you need to explicitly modify that property for it to change.  The “auto refresh” behavior of collections only works for collections which you populate using the DataService.fill method.  So in this case, you would have to both create a new B and add it to A’s collection of B’s for the A.Bcollection property to update.  This could be done on the client, or you could do it in on the server using the DataServiceTransaction api.  It might look at the newly created B and issue updateItem calls for the A destination updating the collection property to include the new B.   Assuming “autoSyncEnabled” was true for the fill/getItem that created A, this would then push out the changes to A’s collection of Bs so it shows up. I suppose that if adding B has a side effect of updating the state of a property of A because of a relationship in the database, simply refreshing A would also get the new version of the data (i.e. call fill or getItem again) In a more complex sense, I have managed objects that are shared components of several other managed objects. (A's contain a collection of B's)... when I update a B, do I need to keep track of every A that has that particular B? Yes, if you are using association properties this is by manually updating association properties.  Another approach is to use fills instead of associations.  In this case, you can pass in the id of item “A” as a fill parameter to retrieve a list of Bs instead of storing the collection of B’s as a property of A.   In this case, after each change to a B, we will go through all fills which have auto-refresh enabled and re-execute them to see if their contents have changed.  If so, we push out the changes to the clients that have those fills.  This can be slow as the number of fills changes so there are ways to optimize that process. I hope this helps.  Does this work for you if you are using hibernate without FDMS?   I guess it might if you are not caching instances and refetch them from the database each time you create a new B…  I think that usually you implement this type of thing with a bi-directional relationship where B also has a reference to one or more As.  In this case, the hibernate docs recommend that you update both sides of the relationship though only one of the properties needs to be changed to persist the state in the database. Jeff __._,_.___ -- Flexcoders Mailing List FAQ: http://groups.yahoo.com/group/flexcoders/files/flexcodersFAQ.txt Search Archives: http://www.mail-archive.com/flexcoders%40yahoogroups.com SPONSORED LINKS Web site design development Computer software development Software design and development Macromedia flex Software development best practice YAHOO! GROUPS LINKS  Visit your group "flexcoders" on the web.    To unsubscribe from this group, send an email to:  [EMAIL PROTECTED]    Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service. __,_._,___