Pascal (Lazarus/Delphi)

Use Socket Object for the Connection

See more REST Examples

The Chilkat Socket API provides many features for establishing connections, which includes the following:

• Connect through an HTTP proxy
• Connect through a SOCKS proxy
• Connect through an SSH tunnel
• Binding to a local IP address
• Client-side Certificates (two-way SSL/TLS)
• Public Key Pinning for TLS connections
• Controlling TLS ciphers

Rather than reproducing all of the properties and methods required for these features, the REST object can use a Socket object's connection by calling the UseConnection method. This allows for an application to use the features of the Socket API to establish the connection, and then use it from the REST API.

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.Rest,
  Chilkat.Socket;

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

procedure RunDemo;
var
  success: Boolean;
  rest: TRest;
  socket: TSocket;
  bTls: Boolean;
  port: Integer;
  maxWaitMs: Integer;
  bAutoReconnect: Boolean;
  responseJson: string;

begin
  success := False;

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

  //  This example shows how to use the Chilkat socket object's connection.
  rest := TRest.Create;
  socket := TSocket.Create;

  //  Establish the connection using the socket object:
  bTls := True;
  port := 443;
  maxWaitMs := 5000;
  success := socket.Connect('www.alphavantage.co',port,bTls,maxWaitMs);
  if (success <> True) then
    begin
      WriteLn('Connect Failure Error Code: ' + socket.ConnectFailReason);
      WriteLn(socket.LastErrorText);
      Exit;
    end;

  bAutoReconnect := True;

  //  Use the connection:
  success := rest.UseConnection(socket,bAutoReconnect);
  if (success <> True) then
    begin
      WriteLn(rest.LastErrorText);
      Exit;
    end;

  //  Get a stock quote:
  //  Sending GET request to https://www.alphavantage.co/query?function=TIME_SERIES_DAILY&symbol=MSFT&apikey=my_api_key
  success := rest.AddQueryParam('function','TIME_SERIES_DAILY');
  success := rest.AddQueryParam('symbol','AAPL');
  success := rest.AddQueryParam('apikey','my_api_key');
  responseJson := rest.FullRequestNoBody('GET','/query');
  if (rest.LastMethodSuccess <> True) then
    begin
      WriteLn(rest.LastErrorText);
      Exit;
    end;

  WriteLn(responseJson);

  //  Sample response:
  //  {
  //      "Meta Data": {
  //          "1. Information": "Daily Prices (open, high, low, close) and Volumes",
  //          "2. Symbol": "AAPL",
  //          "3. Last Refreshed": "2019-12-06",
  //          "4. Output Size": "Compact",
  //          "5. Time Zone": "US/Eastern"
  //      },
  //      "Time Series (Daily)": {
  //          "2019-12-06": {
  //              "1. open": "267.4800",
  //              "2. high": "271.0000",
  //              "3. low": "267.3000",
  //              "4. close": "270.7100",
  //              "5. volume": "25447644"
  //          },
  //          "2019-12-05": {
  //              "1. open": "263.7900",
  //              "2. high": "265.8900",
  //              "3. low": "262.7300",
  //              "4. close": "265.5800",
  //              "5. volume": "18661343"
  //          },
  //          "2019-12-04": {
  //              "1. open": "261.0700",
  //              "2. high": "263.3100",
  //              "3. low": "260.6800",
  //              "4. close": "261.7400",
  //              "5. volume": "16810388"
  //          },
  //  ...
  //          "2019-07-18": {
  //              "1. open": "204.0000",
  //              "2. high": "205.8800",
  //              "3. low": "203.7000",
  //              "4. close": "205.6600",
  //              "5. volume": "18582161"
  //          }
  //      }
  //  }


  rest.Free;
  socket.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.