(Visual FoxPro) Get Access Token for Google Tasks using Service Account JSON Key

Demonstrates how to get an access token for the Google Tasks API using a Service Account JSON key.

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

LOCAL loFac
LOCAL lcJsonKey
LOCAL loGAuth
LOCAL loTlsSock
LOCAL lnSuccess

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

* First load the JSON key into a string.
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.FileAccess')
loFac = CreateObject('Chilkat.FileAccess')
lcJsonKey = loFac.ReadEntireTextFile("qa_data/googleSvcAccountKeys/ChilkatCloud-48f7737c7505.json","utf-8")
IF (loFac.LastMethodSuccess <> 1) THEN
    ? loFac.LastErrorText
    RELEASE loFac
    CANCEL
ENDIF

* A JSON private key should look like this:

* {
*   "type": "service_account",
*   "project_id": "chilkatcloud",
*   "private_key_id": "48f7737c7505bb88eee6a20d09993e10605d466e",
*   "private_key": "-----BEGIN PRIVATE KEY----- ... -----END PRIVATE KEY-----\n",
*   "client_email": "pip-564@chilkatcloud.iam.gserviceaccount.com",
*   "client_id": "109982228323456925225",
*   "auth_uri": "https://accounts.google.com/o/oauth2/auth",
*   "token_uri": "https://oauth2.googleapis.com/token",
*   "auth_provider_x509_cert_url": "https://www.googleapis.com/oauth2/v1/certs",
*   "client_x509_cert_url": "https://www.googleapis.com/robot/v1/metadata/x509/pip-564%40chilkatcloud.iam.gserviceaccount.com"
* }

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.AuthGoogle')
loGAuth = CreateObject('Chilkat.AuthGoogle')
loGAuth.JsonKey = lcJsonKey

* Choose the scope for read/write access.
loGAuth.Scope = "https://www.googleapis.com/auth/tasks"

* Request an access token that is valid for this many seconds.
loGAuth.ExpireNumSeconds = 3600

loGAuth.SubEmailAddress = ""

* Connect to www.googleapis.com using TLS
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.Socket')
loTlsSock = CreateObject('Chilkat.Socket')
lnSuccess = loTlsSock.Connect("www.googleapis.com",443,1,5000)
IF (lnSuccess <> 1) THEN
    ? loTlsSock.LastErrorText
    RELEASE loFac
    RELEASE loGAuth
    RELEASE loTlsSock
    CANCEL
ENDIF

* Send the request to obtain the access token.
lnSuccess = loGAuth.ObtainAccessToken(loTlsSock)
IF (lnSuccess <> 1) THEN
    ? loGAuth.LastErrorText
    RELEASE loFac
    RELEASE loGAuth
    RELEASE loTlsSock
    CANCEL
ENDIF

* Examine the access token:
? "Access Token: " + loGAuth.AccessToken

* Save our access token to a file.
lnSuccess = loFac.WriteEntireTextFile("qa_data/tokens/googleTasks.txt",loGAuth.AccessToken,"utf-8",0)

RELEASE loFac
RELEASE loGAuth
RELEASE loTlsSock