(Swift 3,4,5...) Google People API Refresh Access Token

Demonstrates how to refresh a Google Access Token for the Google People API.

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.

    // It is assumed we previously obtained an OAuth2 access token.
    // This example loads the JSON access token file 
    // saved by this example: Get Google People API OAuth2 Access Token

    let jsonToken = CkoJsonObject()!
    var success: Bool = jsonToken.loadFile("qa_data/tokens/googlePeople.json")
    if success != true {
        print("Failed to load googlePeople.json")
        return
    }

    // The access token JSON looks like this:

    // {
    //   "access_token": "ya29.a0AfH6S ... LAZYFUkf0",
    //   "expires_in": 3599,
    //   "refresh_token": "1//0fL_Ov ... ee0",
    //   "scope": "https://www.googleapis.com/auth/contacts",
    //   "token_type": "Bearer"
    // }

    let oauth2 = CkoOAuth2()!

    oauth2.tokenEndpoint = "https://www.googleapis.com/oauth2/v4/token"

    // Replace these with actual values.
    oauth2.clientId = "GOOGLE-CLIENT-ID"
    oauth2.clientSecret = "GOOGLE-CLIENT-SECRET"

    // Get the "refresh_token"
    oauth2.refreshToken = jsonToken.string(of: "refresh_token")

    // Send the HTTP POST to refresh the access token..
    success = oauth2.refreshAccessToken()
    if success != true {
        print("\(oauth2.lastErrorText!)")
        return
    }

    // The response contains a new access token, but we must keep
    // our existing refresh token for when we need to refresh again in the future.
    jsonToken.update("access_token", value: oauth2.accessToken)

    // Save the new JSON access token response to a file.
    let sbJson = CkoStringBuilder()!
    jsonToken.emitCompact = false
    jsonToken.emitSb(sbJson)
    sbJson.writeFile("qa_data/tokens/googlePeople.json", charset: "utf-8", emitBom: false)

    print("OAuth2 authorization granted!")
    print("New Access Token = \(oauth2.accessToken!)")

}