Create Declaration in Code

rbuser

OK. I have managed to create the Event handler now but for some reason it
does not seem associated with the control that I would expect it to be
associated with.
I am creating an onGetMemo handler for a memo control and although the
control appears green in the RAP tab the OnGetMemo handler icon underlying
this appears as if no handler is assigned, and upon clicking it this is
indeed the case.

Upon changing to Module view the item appears under 'Event Handlers'
It appears as procedure IDBMEMO4OnGetMemo; (note the missing brackets and
Tstrings collection, though these are declared in the method itself).

The code is as follows:-


CodeMod:=TraCodeModule.CreateForReport(Report);
EventProg:= CodeMod.CreateEventHandler(Mem,szRoutineName);

if EventProg=nil then
begin
EventProg:=TraProgram.Create();
EventProg.ProgramName:=szFullRoutineName;
EventProg.ChildType:=ctCreateProgram;
EventProg.ProgramType:=ttProcedure;
end;

Populate the Method body here...

CodeMod.DSExclude([pppcEmpty]);

{ Compile the Code }

CodeMod.BuildAll(false);

I have not posted this beneath my other mail, even though it partially
answers it, as I have some questions still outstanding and I would quite
like them answering too.

Can any bright spark see where I am going wrong, any help would be
greatfully appreciated.

--
Regards

Conrad Rowlands
Callards Technology Ltd

digitalmetaphors

I forgot to mention a few things in the first post, so I'll respond here.

This is what you are looking for:


{get the codemodule for the report}
lCodeModule := raGetCodeModule(ppReport1);

if (lCodeModule = nil) then
begin
lCodeModule := TraCodeModule.Create(ppReport1);
lCodeModule.Report := ppReport1;
end;

In the tip project links provided previously, we make the call to pull the
code module out in a button click event handler, because the form has been
instantiated and there is a RAP code module object in existance in the
report. You can also see that in some cases, such as in the the tip which
moves the group header band before print event from one group to another we
perform the above code. I have to say that the MoveGroupHeaderBeforePrint
tip is cool- Another customer needed to swap event handlers because they
shipped a report template with a bug in it as the RAP event handler was
hooked up to the wrong group header band. The end user had already modified
the template. So, to preserve the end user's template and fix the bug they
didn't have the RAP IDE as an end user, I wrote an example that modified the
RAP code behind the scenes to swap the event handlers for two group header
bands and the end user was able to keep using his report.

There is one example that is more important to you than the others- creating
an event handler. In our main RAP demos, we show how to do this:

{---------------------------------------------------------------------------
---}
{TForm1.CreateRAPCode}

procedure Trap0042Form.CreateRAPCode;
var
lCodeModule: TraCodeModule;
lEventHandler: TraEventHandler;
begin

{get the codemodule for the report}
lCodeModule := raGetCodeModule(FReport);

{CreateEventHandler: parameters: Component, EventName
- calling this method will create a RAP event-handler and
generate a program shell containing the program declaration plus begin
end}

lEventHandler := lCodeModule.CreateEventHandler(FReport.DetailBand,
'BeforeGenerate');

{set BodyText to modify the code between the begin..end}
lEventHandler.SourceLines.Text := lEventHandler.Declaration +
'var' + #13#10 +
' lsFirstName: String;' + #13#10 +
' lsLastName: String;' + #13#10 +
'begin' + #13#10 +
' lsFirstName :=
plClient[''FIRST_NAME''];' + #13#10 +
' lsLastName :=
plClient[''LAST_NAME''];' + #13#10 +
' LabelFullName.Caption := lsFirstName
+ '' '' + lsLastName;' + #13#10 +
'end;';

{compile the code}
lCodeModule.BuildAll(True);

{add code to the memo so we can print it}
FMemoRAPCode.Text := lEventHandler.SourceLines.Text;

end; {procedure, CreateRAPCode}

Cheers,

Jim Bennett
Digital Metaphors

rbuser

Thanks Jim, unfortunately I do not feel that the main thrust of my question
is answered. Let us compare the code and I think you will see what I mean

JB- lCodeModule := raGetCodeModule(FReport);
CR- CodeMod:=TraCodeModule.CreateForReport(Report);

JB- lEventHandler :=
lCodeModule.CreateEventHandler(FReport.DetailBand,'BeforeGenerate');
CR- EventProg:= CodeMod.CreateEventHandler(Mem,szRoutineName);

CR - Also Had extraneous code here, that was never called and did not
impact, now removed

JB- lEventHandler.SourceLines.Text := etc...
CR- Use the Add methods instead, should have no impact.

CR- CodeMod.DSExclude([pppcEmpty]); (Not sure why this is neccessary but it
was in a previous DM sample

JB- lCodeModule.BuildAll(True);
CR- CodeMod.BuildAll(false); (We do not wish for the op to fail on the part
of a dodgy function)

After running the designer I have the function in my designer and it appears
that it is assigned to the control due to the GREEN arrows against the
control, however upon selecting the appropriate method the code window does
not show the appropriate code, it behaves as if the control contains no
handlers.

Upon inserting a handler into that control manually and then viewing the
event handlers via the module view the declarations appear thus:-

procedure IDBMemo2OnGetMemo; - My Handler
procedure IDBMemo2OnGetMemo(Lines: Tstrings); - RAP Created Handler


The thrust of my problem is that I wish my handler to be properly assigned.
What, if anything am I doing wrong. Is the Compile without exceptions having
an impact on this.

Looking forward to your response.

digitalmetaphors

Sorry if I was short on the examination of your code and didn't answer your
question. There are small pieces which can make a difference when creating
code at runtime that is going to be interpreted at runtime. I first wanted
to give you some examples which worked for us here and was hoping to lean
our your skills as a developer to compare and contrast the demos to your
code. So, the difference is that you compile false and we compile true. What
happens when you compile true? Does it work?

If that doesn't work, then send me a very simple example project, where
there is a report with a memo and a single RAP event handler that you want
to create and populate the memo contents in the new event handler when it
prints. I'll make the simple demo work and send it back to you. Send it to
support@digital-metaphors.com

Cheers,

Jim Bennett
Digital Metaphors