B4X

Dropbox Refresh OAuth2 Access Token

See more Dropbox Examples

Demonstrates how to mint a new access token using the refresh token obtained when originally getting the OAuth2 access token. B4X

Dim success As Boolean = False

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

Dim http As ChilkatHttp
http.Initialize("http")

'  Implements the following CURL command:

'  curl -X GET https://api.dropbox.com/oauth2/token \
'      -d grant_type=refresh_token \
'      -d refresh_token=<YOUR_REFRESH_TOKEN> \
'      -u <YOUR_APP_KEY>:<YOUR_APP_SECRET>

'  Use the following online tool to generate HTTP code from a CURL command
'  Convert a cURL Command to HTTP Source Code

http.Login = "DROPBOX_APP_KEY"
http.Password = "DROPBOX_APP_SECRET"

'  Get the refresh token from the JSON we saved when originally getting the access token.
'  (See Get Dropbox OAuth2 Access Token w/ Refresh Token
Dim json As ChilkatJsonObject
json.Initialize
success = json.LoadFile("qa_data/tokens/dropbox.json")
If success = False Then
    Log(json.LastErrorText)
    Return
End If


Dim req As ChilkatHttpRequest
req.Initialize
req.AddParam("grant_type", "refresh_token")
req.AddParam("refresh_token", json.StringOf("refresh_token"))

req.HttpVerb = "POST"
req.ContentType = "application/x-www-form-urlencoded"

Dim resp As ChilkatHttpResponse
resp.Initialize
success = http.HttpReq("https://api.dropbox.com/oauth2/token", req, resp)
If success = False Then
    Log(http.LastErrorText)
    Return
End If


Dim sbResponseBody As ChilkatStringBuilder
sbResponseBody.Initialize
resp.GetBodySb(sbResponseBody)

Dim jResp As ChilkatJsonObject
jResp.Initialize
jResp.LoadSb(sbResponseBody)
jResp.EmitCompact = False

Log("Response Body:")
Log(jResp.Emit)

Dim respStatusCode As Int = resp.StatusCode
Log("Response Status Code = " & respStatusCode)
If respStatusCode >= 400 Then
    Log("Response Header:")
    Log(resp.Header)
    Log("Failed.")
    Return
End If


'  Sample JSON response:
'  (Sample code for parsing the JSON response is shown below)

'  {
'    "access_token": "sl.AC75WPYRqOi0mxcRqlimbV9FKHu04biz5qHwatG3MTgzFK7kLrGVlM9EgP4603tE7bWw0s1rMbTKiHsf37TUshPYvq-3r0qeBr_PrZIAibN8XOQicvboiOnqx6JrDekq-w8D-tE",
'    "token_type": "bearer",
'    "expires_in": 14400
'  }

Dim access_token As String = jResp.StringOf("access_token")
Log("New Access Token: " & access_token)

'  Perhaps update our Dropbox JSON file with the new access token.
'  (The existing refresh token does not change, and can be used over and over to mint new access tokens.)
json.UpdateString("access_token", access_token)

json.WriteFile("qa_data/tokens/dropbox.json")