Pascal (Lazarus/Delphi)

PayPal -- Get an OAuth 2.0 Access Token

See more PayPal Examples

Demonstrates how to send a request to get a PayPal OAuth2 access token. Sends an HTTP request equivalent to the following:

curl https://api.sandbox.paypal.com/v1/oauth2/token \
  -H "Accept: application/json" \
  -H "Accept-Language: en_US" \
  -u "Client-Id:Secret" \
  -d "grant_type=client_credentials"

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.StringBuilder,
  Chilkat.Rest,
  Chilkat.JsonObject,
  Chilkat.CkDateTime;

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

procedure RunDemo;
var
  success: Boolean;
  rest: TRest;
  bAutoReconnect: Boolean;
  responseStr: string;
  json: TJsonObject;
  dateTime: TCkDateTime;
  bLocalTime: Boolean;
  dtNow: Integer;
  sbResponse: TStringBuilder;
  bEmitBom: Boolean;

begin
  success := False;

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

  rest := TRest.Create;

  //  Make the initial connection.
  //  A single REST object, once connected, can be used for many PayPal REST API calls.
  //  The auto-reconnect indicates that if the already-established HTTPS connection is closed,
  //  then it will be automatically re-established as needed.
  bAutoReconnect := True;
  success := rest.Connect('api.sandbox.paypal.com',443,True,bAutoReconnect);
  if (success <> True) then
    begin
      WriteLn(rest.LastErrorText);
      Exit;
    end;

  //  Duplicate this request:

  //  	curl https://api.sandbox.paypal.com/v1/oauth2/token \
  //  	  -H "Accept: application/json" \
  //  	  -H "Accept-Language: en_US" \
  //  	  -u "Client-Id:Secret" \
  //  	  -d "grant_type=client_credentials"

  rest.AddHeader('Accept','application/json');
  rest.AddHeader('Accept-Language','en_US');

  //  For additional help on where to find  your client ID and API secret, see PayPal Client_ID and API_Secret
  rest.SetAuthBasic('PAYPAL_REST_API_CLIENT_ID','PAYPAL_REST_API_SECRET');

  rest.AddQueryParam('grant_type','client_credentials');

  responseStr := rest.FullRequestFormUrlEncoded('POST','/v1/oauth2/token');
  if (rest.LastMethodSuccess <> True) then
    begin
      WriteLn(rest.LastErrorText);
      Exit;
    end;

  WriteLn(rest.LastRequestHeader);

  //  A sample response:

  //  	{
  //  	  "scope": "https://api.paypal.com/v1/payments/.* https://api.paypal.com/v1/vault/credit-card https://api.paypal.com/v1/vault/credit-card/.*",
  //  	  "access_token": "EEwJ6tF9x5WCIZDYzyZGaz6Khbw7raYRIBV_WxVvgmsG",
  //  	  "token_type": "Bearer",
  //  	  "app_id": "APP-6XR95014BA15863X",
  //  	  "expires_in": 28800
  //  	}

  json := TJsonObject.Create;
  json.Load(responseStr);
  json.EmitCompact := False;

  //  Check the response status code.  A 200 indicates success..
  if (rest.ResponseStatusCode <> 200) then
    begin
      WriteLn(json.Emit());
      WriteLn('Failed.');
      Exit;
    end;

  //  Given that the access token expires in approx 8 hours,
  //  let's record the date/time this token was created.
  //  This will allow us to know beforehand if the token
  //  is expired (and we can then fetch a new token).
  dateTime := TCkDateTime.Create;
  bLocalTime := False;
  dtNow := dateTime.GetAsUnixTime(bLocalTime);
  json.AppendInt('tokenCreateTimeUtc',dtNow);

  //  Examine the access token and save to a file.
  WriteLn('Access Token: ' + json.StringOf('access_token'));
  WriteLn('Full JSON Response:');
  WriteLn(json.Emit());

  sbResponse := TStringBuilder.Create;
  sbResponse.Append(json.Emit());
  bEmitBom := False;
  sbResponse.WriteFile('qa_data/tokens/paypal.json','utf-8',bEmitBom);


  rest.Free;
  json.Free;
  dateTime.Free;
  sbResponse.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.