Delphi ActiveX

GetHarvest API V2 OAuth Token

See more GetHarvest Examples

Demonstrates how to get an OAuth2 access token for the GetHarvest v2 API (from a desktop application). Delphi ActiveX

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;
oauth2: TChilkatOAuth2;
url: WideString;
numMsWaited: Integer;
json: TChilkatJsonObject;
fac: TCkFileAccess;

begin
success := 0;

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

oauth2 := TChilkatOAuth2.Create(Self);

// This should be the port in the localhost callback URL for your app.  
// The callback URL would look like "http://localhost:3017/" if the port number is 3017.
oauth2.ListenPort := 3017;

oauth2.AuthorizationEndpoint := 'https://id.getharvest.com/oauth2/authorize';
oauth2.TokenEndpoint := 'https://id.getharvest.com/api/v2/oauth2/token';

// Replace these with actual values.
oauth2.ClientId := 'CLIENT_ID';
oauth2.ClientSecret := 'CLIENT_SECRET';

oauth2.CodeChallenge := 0;

oauth2.Scope := 'all';

// Begin the OAuth2 three-legged flow.  This returns a URL that should be loaded in a browser.
url := oauth2.StartAuth();
if (oauth2.LastMethodSuccess = 0) then
  begin
    Memo1.Lines.Add(oauth2.LastErrorText);
    Exit;
  end;

// Launch the system's default browser navigated to the URL.
success := oauth2.LaunchBrowser(url);
if (success = 0) then
  begin
    Memo1.Lines.Add(oauth2.LastErrorText);
    Exit;
  end;

// Now wait for the authorization.
// We'll wait for a max of 60 seconds.
numMsWaited := 0;
while (numMsWaited < 60000) and (oauth2.AuthFlowState < 3) do
  begin
    oauth2.SleepMs(100);
    numMsWaited := numMsWaited + 100;
  end;

// If there was no response from the browser within 30 seconds, then 
// the AuthFlowState will be equal to 1 or 2.
// 1: Waiting for Redirect. The OAuth2 background thread is waiting to receive the redirect HTTP request from the browser.
// 2: Waiting for Final Response. The OAuth2 background thread is waiting for the final access token response.
// In that case, cancel the background task started in the call to StartAuth.
if (oauth2.AuthFlowState < 3) then
  begin
    oauth2.Cancel();
    Memo1.Lines.Add('No response from the browser!');
    Exit;
  end;

// Check the AuthFlowState to see if authorization was granted, denied, or if some error occurred
// The possible AuthFlowState values are:
// 3: Completed with Success. The OAuth2 flow has completed, the background thread exited, and the successful JSON response is available in AccessTokenResponse property.
// 4: Completed with Access Denied. The OAuth2 flow has completed, the background thread exited, and the error JSON is available in AccessTokenResponse property.
// 5: Failed Prior to Completion. The OAuth2 flow failed to complete, the background thread exited, and the error information is available in the FailureInfo property.
if (oauth2.AuthFlowState = 5) then
  begin
    Memo1.Lines.Add('OAuth2 failed to complete.');
    Memo1.Lines.Add(oauth2.FailureInfo);
    Exit;
  end;

if (oauth2.AuthFlowState = 4) then
  begin
    Memo1.Lines.Add('OAuth2 authorization was denied.');
    Memo1.Lines.Add(oauth2.AccessTokenResponse);
    Exit;
  end;

if (oauth2.AuthFlowState <> 3) then
  begin
    Memo1.Lines.Add('Unexpected AuthFlowState:' + IntToStr(oauth2.AuthFlowState));
    Exit;
  end;

Memo1.Lines.Add('OAuth2 authorization granted!');
Memo1.Lines.Add('Access Token = ' + oauth2.AccessToken);

// Get the full JSON response:
json := TChilkatJsonObject.Create(Self);
json.Load(oauth2.AccessTokenResponse);
json.EmitCompact := 0;
Memo1.Lines.Add(json.Emit());

// The JSON response looks like this:

// Save the JSON to a file for future requests.
fac := TCkFileAccess.Create(Self);
fac.WriteEntireTextFile('qa_data/tokens/getHarvest.json',json.Emit(),'utf-8',0);
end;