raRegisterFunction

rbuser · June 2006

Hi,

I have made sevaral procedures and function wich are added tot the calc tree
in reportbuilder using raRegistering function.

When i add a parameter of type tchart to the signature i get a acces
violation when opening the tree:
result := 'function fillchart(graf:tchart): string;';

do i have to add some other units to the program?

Ruud

nardmoseley · June 2006

I tried a simple example here. At first I received an AV and after some
trial and error was able to get it to work by adding some code to the
Initialization section to register the TChart class.

uses
Chart;

Initialization
RegisterClass(TChart);
raRegisterFunction('fillchart', TmyTestChartFunction);

rbuser · June 2006

Hi Nard,

i tried the same here but it did not make a difference,
any other suggestions?

kind regards,

Ruud

r.bernards@meurs-software.nl

nardmoseley · June 2006

- Here is a copy teh myChartFunc.pas unit that I created and used for
testing. Try a test using this same code.

unit myChartFuncs;

interface

uses
Sysutils, classes,
raFunc,
ppRTTI,
ppChrt,
Chart;

type

TmyChartFunction = class(TraSystemFunction)
public
class function Category: String; override;
end;

TmyFillChartFunction = class(TmyChartFunction)
public
procedure ExecuteFunction(aParams: TraParamList); override;
class function GetSignature: String; override;
end;

implementation

{******************************************************************************
*
** C H A R T F U N C T I O N S
*
{******************************************************************************}

{------------------------------------------------------------------------------}
{ TmyChartFunction.Category }

class function TmyChartFunction.Category: String;
begin
Result := 'Chart';
end;

{------------------------------------------------------------------------------}
{ TmyFillChartFunction.GetSignature }

class function TmyFillChartFunction.GetSignature: String;
begin
Result := 'function FillChart(aChart: TCustomChart): string;';
end;

{------------------------------------------------------------------------------}
{ TmyFillChartFunction.ExecuteFunction }

procedure TmyFillChartFunction.ExecuteFunction(aParams: TraParamList);
var
lChart: TCustomChart;
lsResult: String;
begin

// simple test function, that returns the Name of the chart control
GetParamValue(0, lChart);

lsResult := lChart.Name;

SetParamValue(1, lsResult);

end;

initialization
registerClass(TChart);
raRegisterFunction('FillChart', TmyFillChartFunction);

end.

rbuser · July 2006

The problem stays if i change the type of the parameter in the signature to
something else (integer)then i don't get the error

class function TmyFillChartFunction.GetSignature: String;
begin
Result := 'function FillChart(aChart:TCustomChart): string;';
end;

rbuser · July 2006

I tried this in an other application and there it works.
My own procedure works there as wel.

the settings for search/lib path etc. are the same.

if i use a chart in the report it works so the tchart or tcustomschart are
known to the program.

i don't understand....

nardmoseley · July 2006

That is a mystery indeed, there must a difference between the two somewhere.
I canoot think of anything that would cause it to not work in another
application, except that perhaps theTChart or TCustomChart class is not
registered with Delphi (i.e. with the Delphi RegisterClass call).

raRegisterFunction

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