Pascal (Lazarus/Delphi)

curl with Variable Substitution in an XML Request Body

See more CURL Examples

This example shows how to use variables inside an XML request body using the {{variable_name}} syntax. When the HTTP request’s Content-Type indicates XML, Chilkat automatically applies proper XML entity encoding to each substituted value, ensuring the resulting XML remains valid. Pascal (Lazarus/Delphi)

program ChilkatDemo;

// Demonstrates using the Chilkat Pascal wrapper via the C bridge DLL.
// Builds as a console application under Lazarus (FPC) or Delphi.

{$IFDEF FPC}
  {$MODE DELPHI}
{$ENDIF}
{$APPTYPE CONSOLE}

uses
  {$IFDEF UNIX}
  cthreads,
  {$ENDIF}
  SysUtils,
  CkDllLoader,
  Chilkat.HttpCurl,
  Chilkat.StringBuilder;

// ---------------------------------------------------------------------------

procedure RunDemo;
var
  success: Boolean;
  sbCurl: TStringBuilder;
  curl: THttpCurl;
  sbRawRequest: TStringBuilder;

begin
  success := False;

  //  Variable names are enclosed between {{ and }}

  //  curl -X POST https://api.example.com/api/orders \
  //    -H "Content-Type: application/xml; charset=utf-8" \
  //    -H "Accept: application/xml" \
  //    -d '<order>
  //    <customerName>{{customer_name}}</customerName>
  //    <note>{{note}}</note>
  //    <address>{{address}}</address>
  //    <instructions>{{instructions}}</instructions>
  //  </order>'

  sbCurl := TStringBuilder.Create;
  sbCurl.AppendLn('curl -X POST https://api.example.com/api/orders \");
  sbCurl.AppendLn('  -H "Content-Type: application/xml; charset=utf-8" \");
  sbCurl.AppendLn('  -H "Accept: application/xml" \");
  sbCurl.AppendLn('  -d ''<order>');
  sbCurl.AppendLn('  <customerName>{{customer_name}}</customerName>');
  sbCurl.AppendLn('  <note>{{note}}</note>');
  sbCurl.AppendLn('  <address>{{address}}</address>');
  sbCurl.AppendLn('  <instructions>{{instructions}}</instructions>');
  sbCurl.AppendLn('</order>''');

  curl := THttpCurl.Create;

  //  The values below contain chars that will require XML entity encoding.  
  //  Chilkat will automatically do the encoding because the Content-Type of this request is "application/xml"
  curl.SetVar('customer_name','John & Sons');
  curl.SetVar('note','He said "Ship it ASAP!"');
  curl.SetVar('address','123 <Main> Street');
  curl.SetVar('instructions','Use door #2 & call upon arrival');

  //  To demonstrate how the variables are replaced, this example does not execute the curl command. 
  //  Instead, it generates the raw HTTP request that would be sent if the curl command were run.
  sbRawRequest := TStringBuilder.Create;
  success := curl.ToRawRequest(sbCurl.GetAsString(),sbRawRequest);
  if (success = False) then
    begin
      WriteLn(curl.LastErrorText);
      Exit;
    end;

  WriteLn(sbRawRequest.GetAsString());

  //  The output is shown below.
  //  Notice the chars that were XML entity encoded.

  //  POST /api/orders HTTP/1.1
  //  Accept: application/xml
  //  Host: api.example.com
  //  Content-Type: application/xml; charset=utf-8
  //  Content-Length: 229
  //  
  //  <order>
  //    <customerName>John &amp; Sons</customerName>
  //    <note>He said &quot;Ship it ASAP!&quot;</note>
  //    <address>123 &lt;Main&gt; Street</address>
  //    <instructions>Use door #2 &amp; call upon arrival</instructions>
  //  </order>


  sbCurl.Free;
  curl.Free;
  sbRawRequest.Free;

end;

// ---------------------------------------------------------------------------

begin

  try
    RunDemo;
  except
    on E: Exception do
      WriteLn('Unhandled exception: ', E.ClassName, ': ', E.Message);
  end;

  WriteLn;
  {$IFDEF MSWINDOWS}
  WriteLn('Press Enter to exit...');
  ReadLn;
  {$ENDIF}
end.