How to automatically handle expired access tokens ?

[janvda]

I am just wondering how to automatically handle expired access tokens.

I gradually understand how I can use google.auth.OAuth2() so that it will automatically request a new access token (using the refresh token) when it becomes expired but it is not clear how I should integrate this with this library ?

Should I call again new Photos(...) but this time with the new access token ?

kr
Jan.

[roopakv]

interesting and good case. If I add a setNewToken to the photos object, you could call it after refresh? would that work?

[janvda]

Sorry for the delay I had another issue that blocked me.

Your proposal would be great.

I would call the method rather setNewAccessToken to make clear that it is the access token and not the refresh token that must be passed as argument.

[skybldev]

I had the same problem. Google tokens automatically expire in ~1hr, so one must reload it in advance, to avoid any HTTP - Unauthorized errors. Here is how I did it:

/*
	This doesn't need to be a global var, but it makes things much easier if
	you plan to use it in other parts of the code.
*/
var photos;

main();

async function main() {
	/*
		authorizeGAPI() follows ideal procedure with reading a credentials file,
		initializing google.auth.OAuth2 with those credentials, and calling
		.setCredentials() on it using a local token file. It also returns a JSON
		object representing the token (exact contents of the token file)
	*/
	let [OA2Client, token] = await authorizeGAPI();

	// We only need the access token for this
	photos = new Photos(token.access_token);

	/*
		This is the important part; it will automatically refresh the token and
		Photos object every 45 minutes (2,700,000ms).
	*/
	setInterval(() => refreshGAPIToken(OA2Client), 2700000);
}

async function refreshGAPIToken(OA2Client) {
	console.log("Refreshing GAPI token...");


	// You probably already know about this procedure as you said.
	let token = await OA2Client.refreshAccessToken().catch((err) => {
		console.log(`!! Error refreshing GAPI token: ${err}`);
	});

	/*
		We need to await the whole JSON data to complete for some reason.
		Also the "token" returned is the token JSON plus some stuff we don't need.
	*/
	token = await token.credentials;

	// Delete the old Photos instance just to be sure
	delete photos;

	// Initialize it just like at the start.
	photos = new Photos(token.access_token);

	// Verify that the token has been updated properly
	if (photos.transport.authToken != token.access_token) {
		console.log("!! Error refreshing GAPI token: Unable to update GPhotos token.");

		/*
			For the sake of simplicity, I'm leaving this empty. You can implement
			your own retry mechanics.
		*/
	}
	
	// Write the token to a file for later use.
	await fs.promises.writeFile("./token.json", JSON.stringify(token))
		.catch(err => {
			m.exitErr(`!! Error saving token file, you must fix this first: ${err}`);
		});

	return;
}

In summary: Yes, you do need to initialize a new Photos() object, after making sure you delete the old one.

I have had the code running an evening, overnight, and a morning, (~16hrs) and it has uploaded without fail.

[roopakv]

hmmm maybe we should just build in a way into the photos client to do the refresh with the refresh token so that this is handled for the users.

[skybldev]

I agree, this 'replacing the photos object' thing might lead to memory leaks and is a little bit janky. There should be a way to replace the token like @janvda suggested.

[individual8]

Any changes on this matter in the meantime?

[skybldev]

Update on my implementation: I've been running it for two months without user intervention and can report no memory leaks. Its memory usage has stayed at a constant 177K during that whole time. For now I am confident in saying that this is a reliable way to go about this while such a feature is not yet implemented.

[roopakv]

@skybldev I have support for this here: #47

Curious what you think