(Swift 2) 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 Downloads for the Swift Programming Language MAC OS X (Cocoa) Objective-C/Swift Libs iOS Objective-C/Swift Libs

func chilkatTest() {
    // 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.
    let fac = CkoFileAccess()
    var jsonKey: String? = fac.ReadEntireTextFile("qa_data/googleSvcAccountKeys/ChilkatCloud-48f7737c7505.json", charset: "utf-8")
    if fac.LastMethodSuccess != true {
        print("\(fac.LastErrorText)")
        return
    }

    // 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"
    // }

    let gAuth = CkoAuthGoogle()
    gAuth.JsonKey = jsonKey

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

    // Request an access token that is valid for this many seconds.
    gAuth.ExpireNumSeconds = 3600

    gAuth.SubEmailAddress = ""

    // Connect to www.googleapis.com using TLS
    let tlsSock = CkoSocket()
    var success: Bool = tlsSock.Connect("www.googleapis.com", port: 443, ssl: true, maxWaitMs: 5000)
    if success != true {
        print("\(tlsSock.LastErrorText)")
        return
    }

    // Send the request to obtain the access token.
    success = gAuth.ObtainAccessToken(tlsSock)
    if success != true {
        print("\(gAuth.LastErrorText)")
        return
    }

    // Examine the access token:
    print("Access Token: \(gAuth.AccessToken)")

    // Save our access token to a file.
    success = fac.WriteEntireTextFile("qa_data/tokens/googleTasks.txt", fileData: gAuth.AccessToken, charset: "utf-8", includePreamble: false)

}