(Perl) 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.

Chilkat Perl Downloads Perl Module for Windows, MacOS, Linux, Alpine Linux

use chilkat();

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

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

# Get our current access token.
$jsonToken = chilkat::CkJsonObject->new();
$success = $jsonToken->LoadFile($tokenFilePath);
if ($jsonToken->HasMember("access_token") == 0) {
    print "No access token found." . "\r\n";
    exit;
}

$http = chilkat::CkHttp->new();
$http->put_AuthToken($jsonToken->stringOf("access_token"));

$jsonResponse = $http->quickGetStr("https://www.googleapis.com/calendar/v3/users/me/calendarList");
if ($http->get_LastMethodSuccess() != 1) {

    if ($http->get_LastStatus() != 401) {
        print $http->lastErrorText() . "\r\n";
        print "----" . "\r\n";
        print $http->lastResponseBody() . "\r\n";
        exit;
    }

    # The access token must've expired. 
    # Refresh the access token and then retry the request.
    $oauth2 = chilkat::CkOAuth2->new();

    $oauth2->put_TokenEndpoint("https://www.googleapis.com/oauth2/v4/token");

    # Replace these with actual values.
    $oauth2->put_ClientId("GOOGLE-CLIENT-ID");
    $oauth2->put_ClientSecret("GOOGLE-CLIENT-SECRET");

    # Get the "refresh_token"
    $oauth2->put_RefreshToken($jsonToken->stringOf("refresh_token"));

    # Send the HTTP POST to refresh the access token..
    $success = $oauth2->RefreshAccessToken();
    if ($success != 1) {
        print $oauth2->lastErrorText() . "\r\n";
        exit;
    }

    # 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.
    $sbJson = chilkat::CkStringBuilder->new();
    $jsonToken->put_EmitCompact(0);
    $jsonToken->EmitSb($sbJson);
    $sbJson->WriteFile($tokenFilePath,"utf-8",0);

    print "OAuth2 authorization granted!" . "\r\n";
    print "New Access Token = " . $oauth2->accessToken() . "\r\n";

    # re-try the original request.
    $http->put_AuthToken($oauth2->accessToken());
    $jsonResponse = $http->quickGetStr("https://www.googleapis.com/calendar/v3/users/me/calendarList");
    if ($http->get_LastMethodSuccess() != 1) {
        print $http->lastErrorText() . "\r\n";
        exit;
    }

}

print $jsonResponse . "\r\n";
print "-----------------------------" . "\r\n";