[SOLVED] onDataChange Event when Datasource.dataset reloads
lazarus / 16-Databases

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Lostisimus · 2021-02-07 22:50

I hope you can make sense of my attempt to verbalize my problem, sorry
for that.

I Have two SqlQuery dataset components set up as Master/Detail in
datamodule (connected with a DataSource).
Using a dbGrid for detail data, I can confirm that the setup is
correct, the data changes when i scroll the master.
On a form I am trying to use the onDataChange eventhandler to do stuf
after the detail SqlQuery is reloaded, I think this is also what is
causing the problem (the DataSet reloading in stead of a "regular"
dataChange).
When in the onDataChange eventhandler i try to access the detail
SqlQuery dataset itself I get access violations, because it (the
detail SqlQuery dataset) does not seem to be ready (i guess).
I also tried to use the onDataChange event using a DataSource on the
master SqlQuery dataset, with same result.

Is there a way to catch the right moment after the detail SqlQuery
dataset is reloaded, to program stuf, for instance load non data aware
components?



Thanks in advance.

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Lostisimus · 2021-02-08 13:21

Problem solved, i was really goofing up here.
If you read carefully i am creating an endless loop in the
onDataChange.
This was hidden by trying to address a non assigned dataModule
variable  .
I tryed to remove this post but for some reason i am not able to.

It is now working by using onStateChange in stead of onDataChange
event of the DataSource.

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i procedure
TfrmReadForm.dsVertalingenStateChange(Sender: TObject);begin  with
MainDataMod do  begin    try      /// This check is important, because
also goes through state inactive      if SQLQryVertalingen.State in
[dsBrowse] then      begin        SQLQryVertalingen.First;       
While not SQLQryVertalingen.Eof do        begin          {Bla bla}   
     SQLQryVertalingen.Next;        end;      end;    finally    end; 
end;end;