Change DataSet of each objects on sheet

xychu

I have saved report in file (or database). There are on it barcode (dataset DBDane, datafield ean13 ), text (dataset DBDane, datafield tekst) etc. Everything is from dataset. Dataset is named DBDane.
I want to write multithreaded service. And if one thread makes object of class TfrxDBDataset named DBDane, another can't (I've got exception "A component named DBDane already exists") .
How can I change properties of every elements of my report to change dataset for another name?

my code:

    mDBDane[miejsce]=new TfrxDBDataset(XSVSQLResp);
    mDBDane[miejsce]->DataSet=zapytania[miejsce];
    mDBDane[miejsce]->UserName="DBDane";
    mDBDane[miejsce]->Name="DBDane";// If I change this name report doesn't prepare
    mDBDane[miejsce]->Enabled=true;
    zapytania[miejsce]->Active=true;
    (...)
    raporty[miejsce]=new TfrxReport(XSVSQLResp);
    raporty[miejsce]->EngineOptions->EnableThreadSafe=true;
    raporty[miejsce]->EngineOptions->DestroyForms=false;
    raporty[miejsce]->EngineOptions->ReportThread=this;
    raporty[miejsce]->EngineOptions->SilentMode=true;
    raporty[miejsce]->EngineOptions->UseFileCache=false;

    raporty[miejsce]->EngineOptions->UseGlobalDataSetList = false;
    raporty[miejsce]->EnabledDataSets->Clear();
    raporty[miejsce]->EnabledDataSets->Add(mDBDane[miejsce]);
    (...)
    ms[miejsce]=new TMemoryStream();
    Dekoder[miejsce]=new TIdDecoderMIME(XSVSQLResp);
    Dekoder[miejsce]->DecodeToStream(zapytania2[miejsce]->FieldByName("raport")->AsString,ms[miejsce]);
    ms[miejsce]->Position=0;
    raporty[miejsce]->LoadFromStream(ms[miejsce]);

    raporty[miejsce]->DataSets->Clear();
    raporty[miejsce]->DataSets->Add(mDBDane[miejsce]);
    raporty[miejsce]->DataSets->BeginUpdate();
    raporty[miejsce]->DataSet=mDBDane[miejsce];
    raporty[miejsce]->DataSetName="DBDane";

        raporty[miejsce]->PrepareReport(true)

(...)

Please help!

Anu de Deus

You can change the dataset, but do more things than you did.
The secret is to keep the dataset name stored in a variable (string), so you can replace it everywhere, in every component if necessary.

I have a code that loops through several datasets, creating them on then fly, take a look at this:

fDBDataSetName := 'ffrDBDataset' + inttostr(pIdx); <<--- this is what you are missing mainly

ffrDBDataset := TfrxDBDataset.Create(nil);
ffrDBDataset.Name := fDBDataSetName; //'frxDBDataset1'; << see the name being replaced here?
ffrDBDataset.UserName := fDBDataSetName; //'frxDBDataset1'; << see the name being replaced here?
ffrDBDataset.CloseDataSource := False; << probably not necessary for you
ffrDBDataset.BCDToCurrency := False; << probably not necessary for you
ffrDBDataset.DataSet := fADODataSet; << you can change the dataset source too, with or without changing the name, if you want

pParentReport.DataSets.Add(ffrDBDataset); << this was also missing in your code, I think, so the prepare doesn't fail.

I hope this gives you some ideas. After this, you may need to change the individual Dataset properties of all tfrxMemoView components etc in the report, if it's changed.

Cheers

xychu

Thank for reply.
I know how I can change name of my dataset.
But when I load raport from file I don't know what kind of elements and how named they are loaded.
My question is:
Ist there any solution to write some kind of loop to change DataSet in every element of loaded from file (stream) report?

Anu de Deus

Sure, list all the objects belonging to the report, if they are of a type that uses a dataset (or have it populated) then you change it.
Something like:

<!--fonto:Courier New--><span style="font-family:Courier New"><!--/fonto-->var lC : tfrxComponent;

for i := 0 to fReport.PagesCount - 1 do
begin
for c := 0 to fReport.Pages.Objects.Count - 1 do
begin
lC := tfrxComponent(fReport.Pages.Objects[c]);
if lC is tfrxMemoView then begin
if tfrxMemoView(lC).Dataset <> '' then // maybe <> nil, I didn't try compiling this code, I'm just posting it in the forum.
tfrxMemoView(lC).Dataset := your new dataset.
// maybe you need this too, test it:
tfrxMemoView(lC).text := '';
end;
//repeat situation for bands, or any other db type :
if lC is tfrxMasterData then begin
tfrxMasterData (lC).Dataset := your new dataset.
end;<!--fontc--></span><!--/fontc-->

and so on.

Also, you may need to extend the loop to include all children of the objects you just did

xychu

Hey. Thanks for reply!
I already did it using TList of objects fastReport->AllObjects.
But thanks anyway!