(PureBasic) 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.

For more information, see https://www.dropbox.com/developers/documentation/http/documentation

Chilkat PureBasic Module Download Chilkat PureBasic Module

IncludeFile "CkHttpResponse.pb"
IncludeFile "CkHttp.pb"
IncludeFile "CkStringBuilder.pb"
IncludeFile "CkJsonObject.pb"
IncludeFile "CkHttpRequest.pb"

Procedure ChilkatExample()

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

    http.i = CkHttp::ckCreate()
    If http.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success.i

    ; 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

    CkHttp::setCkLogin(http, "DROPBOX_APP_KEY")
    CkHttp::setCkPassword(http, "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
    json.i = CkJsonObject::ckCreate()
    If json.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success = CkJsonObject::ckLoadFile(json,"qa_data/tokens/dropbox.json")
    If success = 0
        Debug CkJsonObject::ckLastErrorText(json)
        CkHttp::ckDispose(http)
        CkJsonObject::ckDispose(json)
        ProcedureReturn
    EndIf

    req.i = CkHttpRequest::ckCreate()
    If req.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkHttpRequest::ckAddParam(req,"grant_type","refresh_token")
    CkHttpRequest::ckAddParam(req,"refresh_token",CkJsonObject::ckStringOf(json,"refresh_token"))

    resp.i = CkHttp::ckPostUrlEncoded(http,"https://api.dropbox.com/oauth2/token",req)
    If CkHttp::ckLastMethodSuccess(http) = 0
        Debug CkHttp::ckLastErrorText(http)
        CkHttp::ckDispose(http)
        CkJsonObject::ckDispose(json)
        CkHttpRequest::ckDispose(req)
        ProcedureReturn
    EndIf

    sbResponseBody.i = CkStringBuilder::ckCreate()
    If sbResponseBody.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkHttpResponse::ckGetBodySb(resp,sbResponseBody)

    jResp.i = CkJsonObject::ckCreate()
    If jResp.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkJsonObject::ckLoadSb(jResp,sbResponseBody)
    CkJsonObject::setCkEmitCompact(jResp, 0)

    Debug "Response Body:"
    Debug CkJsonObject::ckEmit(jResp)

    respStatusCode.i = CkHttpResponse::ckStatusCode(resp)
    Debug "Response Status Code = " + Str(respStatusCode)
    If respStatusCode >= 400
        Debug "Response Header:"
        Debug CkHttpResponse::ckHeader(resp)
        Debug "Failed."
        CkHttpResponse::ckDispose(resp)

        CkHttp::ckDispose(http)
        CkJsonObject::ckDispose(json)
        CkHttpRequest::ckDispose(req)
        CkStringBuilder::ckDispose(sbResponseBody)
        CkJsonObject::ckDispose(jResp)
        ProcedureReturn
    EndIf

    CkHttpResponse::ckDispose(resp)

    ; 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
    ; }

    access_token.s = CkJsonObject::ckStringOf(jResp,"access_token")
    Debug "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.)
    CkJsonObject::ckUpdateString(json,"access_token",access_token)

    CkJsonObject::ckWriteFile(json,"qa_data/tokens/dropbox.json")


    CkHttp::ckDispose(http)
    CkJsonObject::ckDispose(json)
    CkHttpRequest::ckDispose(req)
    CkStringBuilder::ckDispose(sbResponseBody)
    CkJsonObject::ckDispose(jResp)


    ProcedureReturn
EndProcedure