StrataFrame Forum

ListView Requery After Delete Operation

http://forum.strataframe.net/Topic14543.aspx

By Bill Cunnien - 2/25/2008

I have a ListView that is getting populated on a requery.  I am passing in the ListPopulating method (as recommended) one of the business objects on the form along with the BusinessCloneDataType.  This is working great.  Whereever I need to call the requery method of the ListView, I no longer care about parameters...I just call it.

After a user deletes a record successfully, I thought it would be a good idea to call that requery method.  So, after checking success on the delete and the save events, I call the requery method of the ListView.  The resulting list is wrong.  An entirely different customer is being displayed in the list (the customer comes from a call (PopulatedThroughEvent) in the RowPopulating event).  If I navigate away from the main BO and come back, the ListView shows the correct customer.  If I add a new record and call the requery method, the ListView show the proper customer.  Only the delete is doing this.  So, what am I doing wrong?

Thanks!
Bill

By Trent L. Taylor - 2/25/2008

If I navigate away from the main BO and come back, the ListView shows the correct customer.  If I add a new record and call the requery method, the ListView show the proper customer.  Only the delete is doing this.  So, what am I doing wrong?

I assume that you are deleting the parent record.  The BOs do not cascade the deletions to the child (by default).  You need to clear out the child BO records that are no longer valid by either repopulating the BO, or clearing it out via the Clear method.  Or...delete each of the records that are no longer valid.  More than likely the cascading deletes have taken place on the server, so you just need to clear out the child BO to match the parent.  I recommend doing this manually instead of allowing the deletions or child records to be automatically filtered (other issues that arise from there Smile )

MyBo.Clear()

or


'-- Delete all of the records that need to be deleted (this code would only delete a single record)
MyBo.DeleteCurrentRow(True)


'-- Update the BO so that it doesn't reflect any dirty changes.  By doing this, you can make a change
'   to the BO data and prevent it from trying to persist back to the server.  Once called, the BO will no longer be in a
'   dirty state.
MyBo.CurrentDataTable.AcceptChanges()
By Bill Cunnien - 2/25/2008

Nope...not deleting the parent, just a child.  What I did to get around the problem was to explicitly refill the child BO.  That seems to have done the trick.  Thanks for the help!

Bill

By Trent L. Taylor - 2/25/2008

Nope...not deleting the parent, just a child.  What I did to get around the problem was to explicitly refill the child BO.  That seems to have done the trick. 

That would work, but it is requireing another trip to the server.  I think that you probably called the DeletePrimarykey method instead of the DeleteCurrentRow.  The DeletePrimarykey method just "smokes" it from the server and doesn't update the BO.  However, the DeleteCurrentRow updates the internal data as well as the server, if you call it with a False, otherwise a Save must happen to commit the deleted record.

By Bill Cunnien - 2/26/2008

I was calling DeleteCurrentRow() without a parameter.  I was forced to add the Save() function to get things going, so I used your tactic, instead.  I am now calling DeleteCurrentRow(false).  No need to call Save(), anymore.  Also, in order to get around another issue that I was having I added another temporary BO into the mix so that the ListView would populate properly.  In the RowPopulating event I setup a new BO to reference the BO of the ListView, then I grabbed the foreign key index from the BO and retrieved the field I needed from the customer BO to fill in the name.

It is all quite simple after I worked it all out.  Took a little while.  The goal was to be able to see a list of items, select one, and provide add/edit/delete capabilities in the same window.  I attached an example of what I did.

Thanks for your help!  Have a great day!!
Bill

By Trent L. Taylor - 2/26/2008

Looks good, Bill! Smile