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My helper removes original helpers

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Artur2024:
This work

--- Code: Pascal  [+][-]window.onload = function(){var x1 = document.getElementById("main_content_section"); if (x1) { var x = document.getElementsByClassName("geshi");for (var i = 0; i < x.length; i++) { x[i].style.maxHeight='none'; x[i].style.height = Math.min(x[i].clientHeight+15,306)+'px'; x[i].style.resize = "vertical";}};} ---unit Unit1; {$mode objfpc}{$H+}{$modeswitch TypeHelpers} interface uses  Classes, SysUtils, Forms, Controls, Graphics, Dialogs; type  //HString = type helper for string  //  function MyClear(): String;  //end;   { TForm1 }   TForm1 = class(TForm)    procedure FormClick(Sender: TObject);  private   public   end; var  Form1: TForm1; implementation {$R *.lfm} //function HString.MyClear(): String;//begin//  Result := '';//end;  { TForm1 } procedure TForm1.FormClick(Sender: TObject);var  s: string;begin  s := 'aaa';  ShowMessage(s.Replace('a', 'A'));end; end. 
When I add my helpers, this code not work :(
"Replace" is: unit1.pas(46,17) Error: Illegal qualifier


--- Code: Pascal  [+][-]window.onload = function(){var x1 = document.getElementById("main_content_section"); if (x1) { var x = document.getElementsByClassName("geshi");for (var i = 0; i < x.length; i++) { x[i].style.maxHeight='none'; x[i].style.height = Math.min(x[i].clientHeight+15,306)+'px'; x[i].style.resize = "vertical";}};} ---unit Unit1; {$mode objfpc}{$H+}{$modeswitch TypeHelpers} interface uses  Classes, SysUtils, Forms, Controls, Graphics, Dialogs; type  HString = type helper for string    function MyClear(): String;  end;   { TForm1 }   TForm1 = class(TForm)    procedure FormClick(Sender: TObject);  private   public   end; var  Form1: TForm1; implementation {$R *.lfm} function HString.MyClear(): String;begin  Result := '';end;  { TForm1 } procedure TForm1.FormClick(Sender: TObject);var  s: string;begin  s := 'aaa';  ShowMessage(s.Replace('a', 'A'));end; end. 
How can I add my own helpers?

jamie:
you can inherit from TStringHelper.

If memory serves, I think you specify TStringHelper instead of string.


I would need to look that up.

Blaazen:
https://wiki.freepascal.org/Helper_types


--- Quote ---By default, only one helper type can be active for a type at the same time. This helper is always the last one that is in scope (which follows the usual rules of Pascal).

--- End quote ---

jamie:

--- Code: Pascal  [+][-]window.onload = function(){var x1 = document.getElementById("main_content_section"); if (x1) { var x = document.getElementsByClassName("geshi");for (var i = 0; i < x.length; i++) { x[i].style.maxHeight='none'; x[i].style.height = Math.min(x[i].clientHeight+15,306)+'px'; x[i].style.resize = "vertical";}};} --- TMyStringHelper = type helper(TStringHelper) for Ansistring   //  end;                                                            

Artur2024:
Thank you, now the code works  :D

--- Code: Pascal  [+][-]window.onload = function(){var x1 = document.getElementById("main_content_section"); if (x1) { var x = document.getElementsByClassName("geshi");for (var i = 0; i < x.length; i++) { x[i].style.maxHeight='none'; x[i].style.height = Math.min(x[i].clientHeight+15,306)+'px'; x[i].style.resize = "vertical";}};} ---unit Unit1; {$mode objfpc}{$H+}{$modeswitch TypeHelpers} interface uses  Classes, SysUtils, Forms, Controls, Graphics, Dialogs; type  TMyStringHelper = type helper(TStringHelper) for Ansistring    function MyClear(): String;  end;   { TForm1 }   TForm1 = class(TForm)    procedure FormClick(Sender: TObject);  private   public   end; var  Form1: TForm1; implementation {$R *.lfm} function TMyStringHelper.MyClear(): String;begin  Result := '';end;  { TForm1 } procedure TForm1.FormClick(Sender: TObject);var  s: string;begin  s := 'aaa';  ShowMessage(s.Replace('a', 'A'));  s := s.MyClear();end; end.  

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