Xbase++ Requires Chilkat v10.1.2+

Dropbox: OAuth2 Authorization to Obtain an Access Token

See more Dropbox Examples

Demonstrates how to get a Dropbox OAuth2 access token from a desktop application or script.

This example runs the OAuth 2.0 authorization flow that lets the user sign in to Dropbox and authorize your app.

Xbase++

LOCAL nSuccess
LOCAL oOauth2
LOCAL cUrl
LOCAL nNumMsWaited
LOCAL oJson

nSuccess := 0

//  For more information about the OAuth2, see OAuth 2.0 Authorization Flow

oOauth2 := CreateObject("Chilkat.OAuth2")

//  The port should match the Authorized Redirect URL in your Dropbox app, 
//  which would look like "http://localhost:3017/"
oOauth2:ListenPort := 3017

//  IMPORTANT: One of the OAuth2 redirect URIs for your Dropbox app must be
//  exactly this string:  http://localhost:3017/

oOauth2:AuthorizationEndpoint := "https://www.dropbox.com/oauth2/authorize"
oOauth2:TokenEndpoint := "https://api.dropboxapi.com/oauth2/token"

//  Replace this with your actual Dropbox App Key
oOauth2:ClientId := "DROPBOX_APP_KEY"

//  This is for Require Proof Key for Code Exchange (PKCE)
//  See OAuth2 PKCE Explained
oOauth2:CodeChallenge := 1
oOauth2:CodeChallengeMethod := "S256"

//  Add token_access_type=offline to also get a refresh token in the response
oOauth2:AddAuthQueryParam("token_access_type", "offline")

//  Begin the OAuth2 Authorization code flow.  This returns a URL that should be loaded in a browser.
cUrl := oOauth2:StartAuth()
IF (oOauth2:LastMethodSuccess == 0)
    ? oOauth2:LastErrorText
    oOauth2:destroy()
    RETURN
ENDIF

? "url = " + cUrl

//  Launch the default browser on the system and navigate to the url.
//  The LaunchBrowser method was added in Chilkat v10.1.2.
nSuccess := oOauth2:LaunchBrowser(cUrl)
IF (nSuccess == 0)
    ? oOauth2:LastErrorText
    oOauth2:destroy()
    RETURN
ENDIF

//  Wait for the user to approve or deny authorization in the browser.
nNumMsWaited := 0
DO WHILE (nNumMsWaited < 90000) .AND. (oOauth2:AuthFlowState < 3)
    oOauth2:SleepMs(100)
    nNumMsWaited := nNumMsWaited + 100
ENDDO

//  If the browser does not respond within the specified time, AuthFlowState will be:
//  
//  1: Waiting for Redirect - The OAuth2 background thread is waiting for the browser's redirect request.
//  2: Waiting for Final Response - The thread is awaiting the final access token response.
//  In either case, cancel the background task initiated by StartAuth.

IF (oOauth2:AuthFlowState < 3)
    oOauth2:Cancel()
    ? "No response from the browser!"
    oOauth2:destroy()
    RETURN
ENDIF

//  Check AuthFlowState to determine if authorization was granted, denied, or failed:
//  
//  3: Success - OAuth2 flow completed, the background thread exited, and the successful response is in AccessTokenResponse.
//  4: Access Denied - OAuth2 flow completed, the background thread exited, and the error response is in AccessTokenResponse.
//  5: Failure - OAuth2 flow failed before completion, the background thread exited, and error details are in FailureInfo.

IF (oOauth2:AuthFlowState == 5)
    ? "OAuth2 failed to complete."
    ? oOauth2:FailureInfo
    oOauth2:destroy()
    RETURN
ENDIF

IF (oOauth2:AuthFlowState == 4)
    ? "OAuth2 authorization was denied."
    ? oOauth2:AccessTokenResponse
    oOauth2:destroy()
    RETURN
ENDIF

IF (oOauth2:AuthFlowState != 3)
    ? "Unexpected AuthFlowState:" + Str(oOauth2:AuthFlowState)
    oOauth2:destroy()
    RETURN
ENDIF

? "OAuth2 authorization granted!"

oJson := CreateObject("Chilkat.JsonObject")
oJson:Load(oOauth2:AccessTokenResponse)
oJson:EmitCompact := 0

? "Access Token Response = " + oJson:Emit()

//  A sample access token response:

//  {
//    "access_token": "...",
//    "token_type": "bearer",
//    "expires_in": 14399,
//    "refresh_token": "...",
//    "scope": "account_info.read",
//    "uid": "562542581",
//    "account_id": "dbid:AACQhDS0E3_Vb72Ynd0F-GxGWdTI2qcTHzA"
//  }

? "Access Token = " + oOauth2:AccessToken

//  Save the JSON access token response to a file for subsequent use..
oJson:WriteFile("qa_data/tokens/dropbox.json")

oOauth2:destroy()
oJson:destroy()