(PowerBuilder) Dropbox: OAuth2 Authorization to Obtain an Access Token

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.

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

integer li_rc
oleobject loo_Oauth2
integer li_Success
string ls_Url
integer li_NumMsWaited
oleobject loo_Json

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

// Note: This example requires Chilkat v9.5.0.66 or greater to work properly.

loo_Oauth2 = create oleobject
// Use "Chilkat_9_5_0.OAuth2" for versions of Chilkat < 10.0.0
li_rc = loo_Oauth2.ConnectToNewObject("Chilkat.OAuth2")
if li_rc < 0 then
    destroy loo_Oauth2
    MessageBox("Error","Connecting to COM object failed")
    return
end if

// The port should match the Authorized Redirect URL in your Dropbox app, 
// which would look like "http://localhost:3017/"
loo_Oauth2.ListenPort = 3017

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

loo_Oauth2.AuthorizationEndpoint = "https://www.dropbox.com/oauth2/authorize"
loo_Oauth2.TokenEndpoint = "https://api.dropboxapi.com/oauth2/token"

// Replace these with actual values.
loo_Oauth2.ClientId = "DROPBOX_APP_KEY"
loo_Oauth2.ClientSecret = "DROPBOX_APP_SECRET"
loo_Oauth2.CodeChallenge = 0

// Add token_access_type=offline to also get a refresh token in the response
loo_Oauth2.AddAuthQueryParam("token_access_type","offline")

// Begin the OAuth2 three-legged flow.  This returns a URL that should be loaded in a browser.
ls_Url = loo_Oauth2.StartAuth()
if loo_Oauth2.LastMethodSuccess <> 1 then
    Write-Debug loo_Oauth2.LastErrorText
    destroy loo_Oauth2
    return
end if

// At this point, your application should load the URL in a browser.
// For example, 
// in C#: System.Diagnostics.Process.Start(url);
// in Java: Desktop.getDesktop().browse(new URI(url));
// in VBScript: Set wsh=WScript.CreateObject("WScript.Shell")
//              wsh.Run url
// in Xojo: ShowURL(url)  (see http://docs.xojo.com/index.php/ShowURL)
// in Dataflex: Runprogram Background "c:\Program Files\Internet Explorer\iexplore.exe" sUrl        
// The Microsoft account owner would interactively accept or deny the authorization request.

// Add the code to load the url in a web browser here...
// Add the code to load the url in a web browser here...
// Add the code to load the url in a web browser here...

// Now wait for the authorization.
// We'll wait for a max of 30 seconds.
li_NumMsWaited = 0
do while (li_NumMsWaited < 30000) AND (loo_Oauth2.AuthFlowState < 3)
    loo_Oauth2.SleepMs(100)
    li_NumMsWaited = li_NumMsWaited + 100
loop

// 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 loo_Oauth2.AuthFlowState < 3 then
    loo_Oauth2.Cancel()
    Write-Debug "No response from the browser!"
    destroy loo_Oauth2
    return
end if

// 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 loo_Oauth2.AuthFlowState = 5 then
    Write-Debug "OAuth2 failed to complete."
    Write-Debug loo_Oauth2.FailureInfo
    destroy loo_Oauth2
    return
end if

if loo_Oauth2.AuthFlowState = 4 then
    Write-Debug "OAuth2 authorization was denied."
    Write-Debug loo_Oauth2.AccessTokenResponse
    destroy loo_Oauth2
    return
end if

if loo_Oauth2.AuthFlowState <> 3 then
    Write-Debug "Unexpected AuthFlowState:" + string(loo_Oauth2.AuthFlowState)
    destroy loo_Oauth2
    return
end if

Write-Debug "OAuth2 authorization granted!"

loo_Json = create oleobject
// Use "Chilkat_9_5_0.JsonObject" for versions of Chilkat < 10.0.0
li_rc = loo_Json.ConnectToNewObject("Chilkat.JsonObject")

loo_Json.Load(loo_Oauth2.AccessTokenResponse)
loo_Json.EmitCompact = 0

Write-Debug "Access Token Response = " + loo_Json.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"
// }

Write-Debug "Access Token = " + loo_Oauth2.AccessToken

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


destroy loo_Oauth2
destroy loo_Json