(Delphi ActiveX) URL Encoding Charset in POST Query Params

Demonstrates how to control the URL encoding charset in POST query params.

Chilkat for Delphi Downloads Chilkat ActiveX DLL for Delphi Chilkat non-ActiveX DLL for Delphi * The examples here use the ActiveX DLL.

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Chilkat_TLB;

...

procedure TForm1.Button1Click(Sender: TObject);
var
nameWin1252Encoded: WideString;
sb: TChilkatStringBuilder;
success: Integer;
http: TChilkatHttp;
req: TChilkatHttpRequest;
resp: IChilkatHttpResponse;

begin
// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

// We have the string "MÆRSK".
nameWin1252Encoded := 'M%E6RSK';

// Note: The DecodeAndAppend method is newly added in Chilkat v9.5.0.87
sb := TChilkatStringBuilder.Create(Self);
success := sb.DecodeAndAppend(nameWin1252Encoded,'url','windows-1252');

http := TChilkatHttp.Create(Self);

// We're setting the session log filename so we can see the exact request sent.
http.SessionLogFilename := 'qa_output/sessionLog.txt';

// First demonstrate a simple application/x-www-form-urlencoded POST

req := TChilkatHttpRequest.Create(Self);

// Set the Charset = "utf-8" to cause URL encoding to use utf-8.
req.Charset := 'utf-8';

req.AddParam('name',sb.GetAsString());

resp := http.PostUrlEncoded('https://www.chilkatsoft.com/something',req.ControlInterface);
if (http.LastMethodSuccess = 0) then
  begin
    Memo1.Lines.Add(http.LastErrorText);
    Exit;
  end;

// This is the request that is sent:
// Notice that utf-8 is used in the query param (the letter 'Æ' is %C3%A6)

// 	POST /something HTTP/1.1
// 	Host: www.chilkatsoft.com
// 	Content-Type: application/x-www-form-urlencoded
// 	Content-Length: 15
// 
// 	name=M%C3%A6RSK

// ---------------------------------------------------------------
// Switch to windows-1252

req.Charset := 'windows-1252';

resp := http.PostUrlEncoded('https://www.chilkatsoft.com/something',req.ControlInterface);
if (http.LastMethodSuccess = 0) then
  begin
    Memo1.Lines.Add(http.LastErrorText);
    Exit;
  end;

// This is the request that is sent:
// Notice that windows-1252 is used in the query param (the letter 'Æ' is %E6)

// 	POST /something HTTP/1.1
// 	Host: www.chilkatsoft.com
// 	Content-Type: application/x-www-form-urlencoded
// 	Content-Length: 12
// 
// 	name=M%E6RSK

// ---------------------------------------------------------------
// Let's do the same with SynchronousRequest, switching back to utf-8

req.Path := '/something';
req.HttpVerb := 'POST';
req.ContentType := 'application/x-www-form-urlencoded';

req.Charset := 'utf-8';

resp := http.SynchronousRequest('www.chilkatsoft.com',443,1,req.ControlInterface);
if (http.LastMethodSuccess = 0) then
  begin
    Memo1.Lines.Add(http.LastErrorText);
    Exit;
  end;

// This is the request that is sent:
// Notice that utf-8 is used in the query param (the letter 'Æ' is %C3%A6)

// 	POST /something HTTP/1.1
// 	Host: www.chilkatsoft.com
// 	Content-Type: application/x-www-form-urlencoded
// 	Content-Length: 15
// 
// 	name=M%C3%A6RSK

// ---------------------------------------------------------------
// Let's do a PostXml where the query params are in the HTTP request start line, 
// and the Content-Type is text/xml where the body of the request is XML.

req.Path := '/something';
req.HttpVerb := 'POST';
req.ContentType := 'text/xml';
success := req.LoadBodyFromString('<test>123</test>','utf-8');
req.Charset := 'utf-8';

// Remember... our request object still contains the query param added in the above call to AddParam.

resp := http.SynchronousRequest('www.chilkatsoft.com',443,1,req.ControlInterface);
if (http.LastMethodSuccess = 0) then
  begin
    Memo1.Lines.Add(http.LastErrorText);
    Exit;
  end;

// This is the request that is sent:
// Notice that utf-8 is used in the query param (the letter 'Æ' is %C3%A6)

// 	POST /something?name=M%C3%A6RSK HTTP/1.1
// 	Host: www.chilkatsoft.com
// 	Content-Type: text/xml
// 	Content-Length: 16
// 
// 	<test>123</test>
end;