(PHP Extension) Get a Google Contacts OAuth2 Access Token

Demonstrates how to get a Google Contacts OAuth2 access token from a desktop application or script.

Chilkat PHP Downloads PHP Extension for Windows, Linux, MacOS, Alpine Linux, Solaris

<?php

// The version number (9_5_0) should match version of the Chilkat extension used, omitting the micro-version number.
// For example, if using Chilkat v9.5.0.48, then include as shown here:
include("chilkat_9_5_0.php");

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

$oauth2 = new CkOAuth2();

// For Google OAuth2, set the ListenPort equal to the port specified in the authorized callback URI for the ClientID.
// See http://cknotes.com/setup-google-account-for-google-drive-api-walkthrough/
$oauth2->put_ListenPort(55568);

$oauth2->put_AuthorizationEndpoint('https://accounts.google.com/o/oauth2/v2/auth');
$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');

$oauth2->put_CodeChallenge(true);
$oauth2->put_CodeChallengeMethod('S256');

// These are the scopes for Google Contacts:
// https://www.google.com/m8/feeds/ 	read/write access to Contacts and Contact Groups
// https://www.googleapis.com/auth/contacts.readonly 	read-only access to Contacts and Contact Groups
$oauth2->put_Scope('https://www.google.com/m8/feeds/');

// Begin the OAuth2 three-legged flow.  This returns a URL that should be loaded in a browser.
$url = $oauth2->startAuth();
if ($oauth2->get_LastMethodSuccess() != true) {
    print $oauth2->lastErrorText() . "\n";
    exit;
}

// At this point, your application should load the URL in a browser.
// For example, 
// in C#: System.Diagnostics.Process.Start(url);
// in Java: Desktop.getDesktop().browse(new URI(url));
// in VBScript: Set wsh=WScript.CreateObject("WScript.Shell")
//              wsh.Run url
// in Xojo: ShowURL(url)  (see http://docs.xojo.com/index.php/ShowURL)
// in Dataflex: Runprogram Background "c:\Program Files\Internet Explorer\iexplore.exe" sUrl        
// The QuickBooks account owner would interactively accept or deny the authorization request.

// Add the code to load the url in a web browser here...
// Add the code to load the url in a web browser here...
// Add the code to load the url in a web browser here...

// Now wait for the authorization.
// We'll wait for a max of 30 seconds.
$numMsWaited = 0;
while (($numMsWaited < 30000) and ($oauth2->get_AuthFlowState() < 3)) {
    $oauth2->SleepMs(100);
    $numMsWaited = $numMsWaited + 100;
}

// If there was no response from the browser within 30 seconds, then 
// the AuthFlowState will be equal to 1 or 2.
// 1: Waiting for Redirect. The OAuth2 background thread is waiting to receive the redirect HTTP request from the browser.
// 2: Waiting for Final Response. The OAuth2 background thread is waiting for the final access token response.
// In that case, cancel the background task started in the call to StartAuth.
if ($oauth2->get_AuthFlowState() < 3) {
    $oauth2->Cancel();
    print 'No response from the browser!' . "\n";
    exit;
}

// Check the AuthFlowState to see if authorization was granted, denied, or if some error occurred
// The possible AuthFlowState values are:
// 3: Completed with Success. The OAuth2 flow has completed, the background thread exited, and the successful JSON response is available in AccessTokenResponse property.
// 4: Completed with Access Denied. The OAuth2 flow has completed, the background thread exited, and the error JSON is available in AccessTokenResponse property.
// 5: Failed Prior to Completion. The OAuth2 flow failed to complete, the background thread exited, and the error information is available in the FailureInfo property.
if ($oauth2->get_AuthFlowState() == 5) {
    print 'OAuth2 failed to complete.' . "\n";
    print $oauth2->failureInfo() . "\n";
    exit;
}

if ($oauth2->get_AuthFlowState() == 4) {
    print 'OAuth2 authorization was denied.' . "\n";
    print $oauth2->accessTokenResponse() . "\n";
    exit;
}

if ($oauth2->get_AuthFlowState() != 3) {
    print 'Unexpected AuthFlowState:' . $oauth2->get_AuthFlowState() . "\n";
    exit;
}

// Save the full JSON access token response to a file.
$sbJson = new CkStringBuilder();
$sbJson->Append($oauth2->accessTokenResponse());
$sbJson->WriteFile('qa_data/tokens/googleContacts.json','utf-8',false);

// The saved JSON response looks like this:

// 	{
// 	 "access_token": "ya39.Ci-XA_C5bGgRDC3UaD-h0_NeL-DVIQnI2gHtBBBHkZzrwlARkwX6R3O0PCDEzRlfaQ",
// 	 "token_type": "Bearer",
// 	 "expires_in": 3600,
// 	 "refresh_token": "1/r_2c_7jddspcdfesrrfKqfXtqo08D6Q-gUU0DsdfVMsx0c"
// 	}
// 
print 'OAuth2 authorization granted!' . "\n";
print 'Access Token = ' . $oauth2->accessToken() . "\n";

?>