Import RoundTo into Report Builder

rbuser

Hi Guys,
i try to import the function RoundTo via RAP into Report Builder, but it
does not work.

When I have compiled my program and open the Report, I chance into the
calculation tab and open the tab Language and got an error.

Error Code: "Cannot compile Signature for Zeichenkette function: RoundTo"

Here my Source Code for the import:
unit Import;

interface

uses
SysUtils, Windows, Messages, Classes, Graphics, Controls,
Forms, Dialogs, Math, raFunc, ppRTTI, raIDE, DateUtils;

type
TmyRoundToFunction = class (TraStringFunction)
public
procedure ExecuteFunction(aParams: TraParamList); override;
class function GetSignature: String; override;
end;

implementation

{------------------------------------------------------------------------------}
{ TmyRoundToFunction.GetSignature }

class function TmyRoundToFunction.GetSignature: String;
begin
Result := 'function RoundTo(const AValue: Extended; const ADigit:
TRoundToEXRangeExtended): Extended;';
end;

{------------------------------------------------------------------------------}
{ TmyRoundToFunction.ExecuteFunction }

procedure TmyRoundToFunction.ExecuteFunction(aParams: TraParamList);
var
AValue, varRueckgabe: Extended;
ADigit: TRoundToEXRangeExtended;
begin
GetParamValue(0, AValue);
GetParamValue(1, ADigit);

varRueckgabe := RoundTo(AValue, ADigit);

SetParamValue(2, varRueckgabe);

end;

initialization
raRegisterFunction('RoundTo', TmyRoundToFunction);

finalization
raUnRegisterFunction('RoundTo');

end.

Are there any problems with the data typs (TRoundToEXRangeExtended) or
where is the problem?




Another question: How can I use functions from delphi in designtime mode.

nicocizik

Hi David,

You are correct, RAP is not going to be able to resolve the
TRoundToEXRangeExtended type. Perhaps try using a simpler type (String
or Integer) and convert to the TRoundToEXRangeExtended type inside the
Execute routine.


Regards,

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

rbuser

Hi Nico,
can you please give me some source code, because I don't know how to do
this.

Regards, David
Am 11.04.2011 15:16, schrieb Nico Cizik (Digital Metaphors):

rbuser

Here my solution:

Uses
SysUtils, raFunc, ppRTTI, Math;

type
TmyRoundToFunction = class(TraSystemFunction)
public
class function Category: string; override;
procedure ExecuteFunction(AParams: TraParamList); override;
class function GetSignature: string; override;
end;

implementation

class function TmyRoundToFunction.Category: string;
begin
Result := 'Crystal Reports';
end;

procedure TmyRoundToFunction.ExecuteFunction(AParams: TraParamList);
var
AValue: Extended;
AResult: Extended;
ATempDigit: Integer;
ADigit: TRoundToEXRangeExtended; // [-20 .. 20]
begin
GetParamValue(0, AValue);
GetParamValue(1, ATempDigit);
try
ADigit := ATempDigit; // prüfen auf TRoundToEXRangeExtended
AResult := RoundTo(AValue, ADigit);
SetParamValue(2, AResult);
except
raise Exception.Create('ADigit ist kein TRoundToEXRangeExtended');
end;
end;

class function TmyRoundToFunction.GetSignature: string;
begin
Result := 'function RoundTo(const AValue: Extended; const ADigit:
Integer): Extended;';
end;

initialization
raRegisterFunction('RoundTo', TmyRoundToFunction);

finalization
raUnRegisterFunction('RoundTo');

end.