(Delphi ActiveX) URL Encoding Charset in POST Query Params

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

Note: This example requires Chilkat v11.0.0 or greater.

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
success: Integer;
nameWin1252Encoded: WideString;
sb: TChilkatStringBuilder;
http: TChilkatHttp;
req: TChilkatHttpRequest;
resp: TChilkatHttpResponse;

begin
success := 0;

// 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';

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());

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

resp := TChilkatHttpResponse.Create(Self);
success := http.HttpReq('https://www.chilkatsoft.com/something',req.ControlInterface,resp.ControlInterface);
if (success = 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';
req.HttpVerb := 'POST';
req.ContentType := 'application/x-www-form-urlencoded';

success := http.HttpReq('https://www.chilkatsoft.com/something',req.ControlInterface,resp.ControlInterface);
if (success = 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 HttpSReq, switching back to utf-8

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

req.Charset := 'utf-8';
success := http.HttpSReq('www.chilkatsoft.com',443,1,req.ControlInterface,resp.ControlInterface);
if (success = 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 POST with XML body 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.
success := http.HttpSReq('www.chilkatsoft.com',443,1,req.ControlInterface,resp.ControlInterface);
if (success = 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;