How can I get a token for the Drive API? - node.js

Question

I want to implement the Google Drive API to my web application using NodeJS and I'm struggling when I try to get a token via OAuth.
I've copied the code from this guide and run the script using Node and it returns an error in this line:
var redirectUrl = credentials.installed.redirect_uris[0];
Googling around I found that I can set that variable as http://localhost:8080 and set the same value in the Authorized redirect URIs configuration in the Google Developers Console and that error goes away, fine, it works. Now it asks for a code that I should get by using an URL.
https://accounts.google.com/o/oauth2/auth?access_type=offline&scope=https%3A%2F%2Fwww.googleapis.com%2Fauth%2Fdrive.metadata.readonly&response_type=code&client_id=CLIENT_ID&redirect_uri=http%3A%2F%2Flocalhost%3A8080
Then I've added the client id and enter to that URL with Chrome and then returns a connection refused error. No clue what to do in here, I searched about my problem and I can't found an answer. By looking at the direction bar in Chrome I see that there's a parameter called code and after it, there's random numbers and letters. Like this:
http://localhost:8080/?code=#/r6ntY87F8DAfhsdfadf78F7D765lJu_Vk-5qhc#
If I add any of these values it returns this error...
Error while trying to retrieve access token { [Error: invalid_request] code: 400 }
Any ideas on what should I do? Thanks.

Answer 1

Did you follow all the directions on the page you indicated, including all of those in Step 1 where you create the credentials in the console and download the JSON for it? There are a few things to note about creating those credentials and the JSON that you get from it:
The steps they give are a little different from what I went through. They're essentially correct, but the "Go to credentials" didn't put me on the page that has the "OAuth Consent Screen" and "Credentials" tabs on the top. I had to click on the "Credentials" left navigation for the project first.
Similarly, on the "Credentials" page, my button was labeled "Create Credentials", not "Add Credentials". But it was a blue button on the top of the page either way.
It is very important that you select "OAuth Client ID" and then Application Type of "Other". This will let you create an OAuth token that runs through an application and not through a server.
Take a look at the client_secret.json file it tells you to download. In there, you should see an entry that looks something like "redirect_uris":["urn:ietf:wg:oauth:2.0:oob","http://localhost"] which is the JSON entry that the line you reported having problems with was looking for.
That "urn:ietf:wg:oauth:2.0:oob" is a magic string that says that you're not going to redirect anywhere as part of the auth stage in your browser, but instead you're going to get back a code on the page that you will enter into the application.
I suspect that the "connection refused" error you're talking about is that you used "http://localhost:8080/" for that value, so it was trying to redirect your browser to an application running on localhost... and I suspect you didn't have anything running there.
The application will prompt you to enter the code, will convert the code into the tokens it needs, and then save the tokens for future use. See the getNewToken() function in the sample code for where and how it does all this.

Answer 2

You need to use this code to exchange for a token. I'm not sure with nodejs how to go about this but in PHP I would post the details to the token exchange url. In javascript you post array would look similar to this ....
var query = {'code': 'the code sent',
'client_id': 'your client id',
'client_secret': 'your client secret',
'redirect_uri': 'your redirect',
'grant_type': 'code' };
Hope this helps

Answer 3

Change redirect uri from http://localhost:8080 to https://localhost:8080.
For this add SSL certificates to your server.