(Node.js) Automatically Refresh Token for 401 Unauthorized

Demonstrates how to automatically refresh an access token (without user interaction) when the token expires and a 401 Unauthorized response is received.

Install Chilkat for Node.js and Electron using npm at Chilkat npm packages for Node.js Chilkat npm packages for Electron on Windows, Linux, MacOSX, and ARM

var os = require('os');
if (os.platform() == 'win32') {  
    if (os.arch() == 'ia32') {
        var chilkat = require('@chilkat/ck-node21-win-ia32');
    } else {
        var chilkat = require('@chilkat/ck-node21-win64'); 
    }
} else if (os.platform() == 'linux') {
    if (os.arch() == 'arm') {
        var chilkat = require('@chilkat/ck-node21-arm');
    } else if (os.arch() == 'x86') {
        var chilkat = require('@chilkat/ck-node21-linux32');
    } else {
        var chilkat = require('@chilkat/ck-node21-linux64');
    }
} else if (os.platform() == 'darwin') {
    if (os.arch() == 'arm64') {
        var chilkat = require('@chilkat/ck-node21-mac-m1');
    } else {
        var chilkat = require('@chilkat/ck-node21-macosx');
    }
}

function chilkatExample() {

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

    var tokenFilePath = "qa_data/tokens/googleCalendar.json";

    // Get our current access token.
    var jsonToken = new chilkat.JsonObject();
    var success = jsonToken.LoadFile(tokenFilePath);
    if (jsonToken.HasMember("access_token") == false) {
        console.log("No access token found.");
        return;
    }

    var http = new chilkat.Http();
    http.AuthToken = jsonToken.StringOf("access_token");

    var jsonResponse = http.QuickGetStr("https://www.googleapis.com/calendar/v3/users/me/calendarList");
    if (http.LastMethodSuccess !== true) {

        if (http.LastStatus !== 401) {
            console.log(http.LastErrorText);
            console.log("----");
            console.log(http.LastResponseBody);
            return;
        }

        // The access token must've expired. 
        // Refresh the access token and then retry the request.
        var oauth2 = new chilkat.OAuth2();

        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.StringOf("refresh_token");

        // Send the HTTP POST to refresh the access token..
        success = oauth2.RefreshAccessToken();
        if (success !== true) {
            console.log(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.UpdateString("access_token",oauth2.AccessToken);

        // Save the new JSON access token response to a file.
        var sbJson = new chilkat.StringBuilder();
        jsonToken.EmitCompact = false;
        jsonToken.EmitSb(sbJson);
        sbJson.WriteFile(tokenFilePath,"utf-8",false);

        console.log("OAuth2 authorization granted!");
        console.log("New Access Token = " + oauth2.AccessToken);

        // re-try the original request.
        http.AuthToken = oauth2.AccessToken;
        jsonResponse = http.QuickGetStr("https://www.googleapis.com/calendar/v3/users/me/calendarList");
        if (http.LastMethodSuccess !== true) {
            console.log(http.LastErrorText);
            return;
        }

    }

    console.log(jsonResponse);
    console.log("-----------------------------");

}

chilkatExample();