Default ADO connection

rbuser

Dear all,
I have gone through the tech tips and other posts and still can't
work this out.

I have an application where the user can design reports and store them in th
database.

Within the same app the user can select reports using
ppreport3.Template.LoadFromDatabase and all is well.

Now I want to access the same reports from another app.

I am using the same code, however when I go to print the report up pops the
DefaultADO login box.

I know that the database settings from the report creation in the first app
is ADOconnection1. I added a connection with this name to my new form.
I changed the ppReport component to point ot this database property.

I left the LoginPrompt for the connection set to true.

Now when I print the report, it brings up the login box for adoconnection1.
I press OK and then the DefaultADO login box appears.

So it wants to connect to 2 connections.

What am I doing wrong?

thanks

John

nicocizik

Hi John,

The database connection information is stored inside the template so once
you load the template, the connection setting you gave the report object is
overwritten. Try using the template event OnLoadEnd to assign the database
connection. See the article below on using template events.

----------------------------------------------
Tech Tip: Using Template Events
----------------------------------------------

The Report.Template object has several events that can be used for
customizing what happens when a report is loaded or saved:

- OnLoadStart
- OnLoadEnd
- OnNew
- OnSaveStart
- OnSaveEnd


The OnLoadEnd and OnNew events are often used to perform actions related
to report and data initialization.

The OnSaveEnd event is often used to save additional descriptive
("meta") data to the database each time the report is saved.

Example:

The Report.Template events are public and therefore must be assigned at
run-time.


1. In the private section of your form declaration you can declare an
event-handler method:

TForm = class(TForm)
private
procedure myTemplateOnLoadEndEvent(Sender: TObject);

public

end;


2. In the Form.OnCreate event, you can assign the event-handler to the
event:

procedure TForm1.FormCreate(Sender: TObject);
begin

ppReport1.Template.OnLoadEnd := myTemplateOnLoadEndEvent;

end;


3. Implement the event-handler method:

procedure TForm1.myTemplateOnLoadEndEvent(Sender: TObject);
begin

{add code here to initial the report or data, etc. }
ppReport1.PrinterSetup.MarginTop := 0.5;

end;


--
Regards,

Nico Cizik
Digital Metaphors
http://www.digital-metaphors.com

rbuser

Dear Nico,
I have done that and no joy. Are there other database settings I
need to look at?

My code is shown below. It steps through the reportonload event ok.

thanks

John

main proc
...
ppreport3.Template.DatabaseSettings.Name :=
dmprintorders.qlulabelsnewitemname.AsString;
if
ReportLocateRecordEvent(sender,dmprintorders.qlulabelsnewitemname.AsString)
then
ppreport3.Template.LoadFromDatabase;

ppreport3.PrinterSetup.PrinterName:=rbitemtable.fieldbyname('printer').asstr
ing;
ppreport3.DeviceType:='screen';
ppreport3.ShowPrintDialog:=false;
ppreport3.DataPipeline:=ppDBPipeline1;
ppreport3.Print;
...

function TfrmPrintDialog1.ReportLocateRecordEvent(Sender: TObject; const
aReportName:String): Boolean;
begin
result:=false;
rbitemtable.Open;
if rbitemtable.Locate('folderid;itemname', vararrayof([0,
aReportName]),[])
then
Result :=true;
end;

procedure TfrmPrintDialog1.ReportOnloadEnd(Sender: TObject);
begin
ppreport3.Template.DatabaseSettings.DataPipeline:=pipedb;
// the pipe component on the form, links to rbItemtable component.
ppreport3.Template.DatabaseSettings.TemplateField:='template';
ppreport3.Template.DatabaseSettings.NameField:='itemname';
end;




I have sterpped through and it is loading the correct template. I then

nicocizik

Sorry John, perhaps I wasn't clear. The reason you would be getting the
default ADO connection would be that DADE cannot find the connection defined
when the templates were created. This is the equivalent of going to the
Data tab and selecting Data Settings from the file menu. These are the data
settings I was referring to when the OnLoadEnd event is fired. Setting the
Template.DatabaseSettings will most likely not have any effect as the
template has already been loaded.

-------------------------------------------------
Tech Tip: How to modify the DatabaseName stored
with a DADE Query
-------------------------------------------------

Currently when DADE is used to create dataviews,
the DatabaseName is stored as part of the query
definition. (This is consistent with Delphi's
approach to specifying a database connection for
a Query object).

In some cases, you may decide that the
DatabaseName needs to be modified at a later date.

We recommend that the DatabaseName
refer to a TDatabase connection component or to
a FieldAlias to provide flexibility for changing
the connection parameters.

A second way to handle this issue is to implement
some code that specifies a DatabaseName
whenever a template is loaded. This can be accomplished
by using the Report.Template.OnLoadEnd event.


1. Declare an event-handler procedure in the private
section of your form declaration.

type
myForm = class(TForm)
private
procedure ReportTemplateLoadEndEvent(Sender: TObject);
public
end;


2. Use the FormCreate event to assign the event-handler to
the event property.

procedure myForm.FormCreate(Sender: TObject)
begin
Report1.Template.OnLoadEnd := ReportTemplateLoadEndEvent;

end;

3. Add code to the event-handler to specify the database name.


procedure myForm.ReportTemplateLoadEndEvent(Sender: TObject)
var
lSQL: TdaSQL;

begin
if GetSQLObject(Report1, lSQL) then
lSQL.DatabaseName := Designer.DataSettings.DatabaseName;

end;


4. Below is a tech tip for extracting the SQL object
from a report. TdaSQL is a class defined in daQClass.pas.

-------------------------------------------------
Tech Tip: How to access the SQL object associated
with a Report created using DADE
-------------------------------------------------

uses
daDatMod;


function GetSQLObject(aReport: TppReport; var aSQL: TdaSQL): Boolean;
var
lDataModule: TdaDataModule;
lDataView: TdaDataView;
begin

aSQL := nil;

{get the datamodule}
lDataModule := daGetDataModule(aReport);

if (lDataModule <> nil) then
begin
lDataView := lDataModule.DataViews[0];

if (lDataView <> nil) and (lDataView is TdaQueryDataView) then
aSQL := TdaQueryDataView(lDataView).SQL;

end;

Result := (aSQL <> nil);

end;


--
Regards,

Nico Cizik
Digital Metaphors
http://www.digital-metaphors.com

rbuser

Dear Nico,
where do I find 'GetSQLObject'

I have added units daQclass, daDatMod, daSQL, daDataView, daQueryDataView,
daADO, daDataModule, daDatamanager

and still no joy!

regards

John

rbuser

Dear Nico,
forget last email, I get it that I have to include the GetSQLObject
function myself.
I have done this, and now I am stuck on the line
lSQL.DatabaseName := Designer.DataSettings.DatabaseName;

'Designer' is not declared. What is it referring to?

regards

John

nicocizik

Hi John,

This is simply referring to the database name used by the TppDesigner
object. You can manually set this as well to the name of the connection on
your form.

--
Regards,

Nico Cizik
Digital Metaphors
http://www.digital-metaphors.com

rbuser

Dear Nico,
great, it now works fine.

Many thanks

John