Adding Custom Info to Templates

rbuser

Hi, there was a TechTip called 'Adding Custom Info to Templates' in the tech
tips newsgroup that appears to no longer be there. I was wondering if it
would be possible to view what was written in that file please.

The reason being is that we're saving additional information into the
database and was wondering the correct procedure for doing it.

Thanks!

rbuser

Hi Nigel Huband,

reset your newsgroup reader for that group! The tech-tip you mentioned is still available there!



-----------------------------------------------------
Tech Tip: Storing Custom Information with Templates
-----------------------------------------------------

Question:
---------

How can I store descriptive information with my report template?


Solution:
---------

1. If you are storing the templates to a database, then you can use the
Report.Template.OnSaveEnd and OnLoadEnd events to store and load the
custom information to appropriate data fields for the record. (This is
the technique used by the ReportExplorer.)

2. If you are storing templates to .rtm files, then you will need to
store the custom information in an Offset area of the template file. The
Report.Template object enables you do this by utilizing the
Template.Offset property and the Template.OnLoadStart and OnLoadEnd
events. Below is a detailed example.



Example:
--------
- Create a new application.
- Add to the main form one TButton, one TppReport and one TppDesigner.

- Set the Designer's Report property to ppReport1.
- Add ppTypes to the uses clause.


type
TForm1 = class(TForm)
Button1: TButton;
ppReport1: TppReport;
ppDesigner1: TppDesigner;
procedure FormCreate(Sender: TObject);
procedure Button1Click(Sender: TObject);
private
procedure LoadReportStreamEvent(Sender: TObject; Stream: TStream);
procedure SaveReportStreamEvent(Sender: TObject; Stream: TStream);

public

end; { class TForm1 }


{note: use compiler directive to declare strings as 'ShortStrings'
this is required for record structures}

{$H-}

{record structure used to store information inside report template }
TmyTemplateInfo = record
HeaderID: Integer;
Comments: String;
DateTime: TDateTime;

end; {record, TppTemplateRec}

{$H+}


const
cHeaderID = 12345;

implementation


{-------------------------------------------------}
{ TForm1.FormCreate }

procedure TForm1.FormCreate(Sender: TObject);
begin

{setup Template events }
ppReport1.Template.Format := ftASCII;
ppReport1.Template.Offset := SizeOf(TmyTemplateInfo);
ppReport1.Template.OnLoadStart := LoadReportStreamEvent;
ppReport1.Template.OnSaveEnd := SaveReportStreamEvent;

end; {procedure, FormCreate}

{-------------------------------------------------}
{ TForm1.Button1Click }

procedure TForm1.Button1Click(Sender: TObject);
begin

ppDesigner1.Show;

end; {procedure, Button1Click}

{--------------------------------------------------}
{ TForm1.LoadReportStreamEvent }

procedure TForm1.LoadReportStreamEvent(Sender: TObject; Stream:
TStream);
var
lTemplateInfo: TmyTemplateInfo;
lsMessage: String;

begin

{read string stored in template header }
Stream.Seek(0, soFromBeginning);
Stream.Read(lTemplateInfo, SizeOf(TmyTemplateInfo));

{note: if not one of the templates with our header info, then set
Offset to 0 }
if lTemplateInfo.HeaderID = cHeaderID then
begin
lsMessage := 'Reading data from template file: ' + #13#10 + #13#10
+
lTemplateInfo.Comments + ' (' +
DateTimeToStr(lTemplateInfo.DateTime) + ')';

MessageDlg(lsMessage, mtInformation, [mbOK],0);
ppReport1.Template.Offset := SizeOf(TmyTemplateInfo);
end
else
ppReport1.Template.Offset := 0;

end; {procedure, LoadReportStreamEvent}


{-----------------------------------------------------------------------
-------}
{ TForm1.SaveReportStreamEvent }

procedure TForm1.SaveReportStreamEvent(Sender: TObject; Stream:
TStream);
var
lTemplateInfo: TmyTemplateInfo;
lsMessage: String;

begin

lTemplateInfo.HeaderID := cHeaderID;
lTemplateInfo.Comments := 'This comment is being stored inside the
report template, ' + #13#10 +
'along with the date and time written. ';
lTemplateInfo.DateTime := Now;

{write info to template header}
Stream.Seek(0, soFromBeginning);
Stream.Write(lTemplateInfo, SizeOf(TmyTemplateInfo));

lsMessage := 'Writing data to template file: ' + #13#10 + #13#10 +
lTemplateInfo.Comments + ' (' +
DateTimeToStr(lTemplateInfo.DateTime) + ')';
MessageDlg(lsMessage, mtInformation, [mbOK],0);

end; {procedure, SaveReportStreamEvent}



regards,
Chris Ueberall;