How to save report template into database via LoadFromStream and SavetoStream?

rbuser

Hi dear,

How i will use stream to save report template. Actually I have created my
own application interface and not using the explorer component because of
the company requirement. So please let me know the way to save report via
streaming.


regards,
Nasir Mahmood Butt

rbuser

Hi Nasir,

load a stream from the record, the stream loading from a table's field is
database (component depending) depending (check the documentation), then you
can load the template from that stream.

regards,
Chris Ueberall;

rbuser

Hi Chris,

I have used LoadFromStream and SaveToStream Methods of Template Object but
it does not load the Report information through LoadFromStream method and
returns me an error 'Reading Stream Error'. What the method i did to
implement this streaming technique is paste the Memo control on the form and
called the method to save Stream information into Memo Control when clicked
the save menu opiton from the designer and it is successful but it does not
load the report information from the Memo Control at the time of opening. So
please let me know why it is happening.


regards,
Nasir Mahmood Butt

rbuser

Hi Nasir,

Sorry, but I'm a little bit puzzled about your 'Memo Control'.
Can you show us some code of your doing.
What do you want to achieve?

regards,
Chris Ueberall;

but
and
clicked
not
So
is

rbuser

Hi Chris,


This code saves report information into stream and then i load memo control
with that stream but when i load report from saved information into memo
control, it does not load and give me an error 'Stream Read Error'. I could
not find out the problem.

Added Controls on a Form are as listed below:

1. Memo1

2. ppReport1

3. ppDesigner1

4. Button1 - Caption := Save to Stream

5. Button2 - Caption := Load From Stream


Private

MyMenue: TMainMenu;
SubMenu: TMenuItem;
ReportStream : TMemoryStream;

Procedure ReportSave(Sender : TObject);


procedure TStreamForm.Button1Click(Sender: TObject);
begin

MyMenue:= ppDesigner1.Menu;
SubMenu:= MyMenue.Items [0];

if (SubMenu.Items[5].Name = 'mniFileSave') then
begin
SubMenu.Items[5].OnClick := ReportSave;
end;

ppReport1.Template.New;

ppDesigner1.Show;

end;


procedure TStreamForm.ReportSave(Sender : TObject);
begin

ReportStream:= TMemoryStream.Create;
ppReport1.template.SaveToStream(ReportStream);

ReportStream.Position := 0;

Memo1.Clear;
Memo1.Lines.LoadFromStream(ReportStream);

ReportStream.Free;

ShowMessage('Save Report');

end;


procedure TStreamForm.Button2Click(Sender: TObject);
begin

ppReport1.Template.New;

ReportStream:= TmemoryStream.Create;
Memo1.Lines.SaveToStream (ReportStream);

ReportStream.Position := 0;

ppReport1.template.LoadFromStream(ReportStream);

ppDesigner1.Show;

ReportStream.Free;

end;



regards,

Nasir Mahmood Butt

rbuser

Nasir,

is the template format of type 'ftASCII', otherwise the TMemo wouldn't be
the right container.
I would use a file (or any other object ready for storing BLOBs) as
storage, not a TMemo.
You can load it into the TMemo for visualizing.

regards,
Chris Ueberall;

control
could
Object
form
does
field

rbuser

Hi Chris,

After changing report format to 'ftASCII', now the report is successfully
saved from stream to database and loaded back properly as well. But is it a
limitation that we can't perform these steps with report format of
'ftBinary'? If we can do with this format then please let me know also and
what are the limitation which must be kept in mind during saving report into
database from stream and as well as back to loading from database to stream.

Code example would be higly appreciated.

regards,
Nasir Mahmood Butt

rbuser

Hi Nasir,

Sorry, this isn't a limitation of ReportBuilder, this is a limitation of
TMemo.
When loading a TMemo, a container for TEXT, the binary will be scrampled,
that's by design.
(You may load any executable in notepad and save it to file, good luck).
There is no need to store a binary report in a TMemo.
You can use any container designed for binary data as storage, TStream and
descendants, database BLOB fields, ...
To load and save from a table's BLOB field, usually you have to create a
TBlobStream (some databases uses their own BlobStream components, see your
database documentation).
There are no other requirements or knowledge necessary, standard stream
handling, no secrets.

regards,
Chris Ueberall;

a
into
stream.