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Login with Google using OAuth2 for client-side web app
branch: master


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Login with Google using OAuth2 for client-side web app, completes login flow discribed in Using OAuth 2.0 for Client-side Applications.

This library is a spin-off project from HTML5 Word Cloud. The original commits can be found in here.

Simple usage

  1. Load the script with <script> or as an AMD module.
  2. Create an instance of the library with var go2 = GO2.init(options), where options should contain at least the clientId you got from the Google API Console.
  3. Attach your callbacks to go2.onlogin and go2.onlogout. You will be able to get the accessToken from onlogin callback or from the GO2.getAccessToken() method.
  4. (Immediate mode) At this point, you may call go2.login(false, true) and to silently test and regain the previous approvial. If it's approved, onlogin callback will fire.
  5. Call go2.login() to start an interactive login process, with a popup. The call must be a result of a user action, such as a click, to prevent popup blocker.

Check out comments in the script source code for detail.


Why not use library supplied by Google and reinvent the wheel?

Because I can; also because the library is light-weighted and transparent to me. For some reason, I cannot get auth library to load without getting the entire client library; onload callback never fires.

You are very welcome to use the library from Google since it will be better supported.

What can I do with the accessToken I got once the login is completed?

You can

  • Use the token to request data from Google's server directly from the client-side web app in the browser (with JSON-P or CORS), for example, this is how HTML5 Word Cloud does it.
  • Send the token to your own server, verify it with Google to associate a Google account with a user session on your site. Documentation here.


To run tests, first you would need to pull the required QUnit and Sinon.JS library by running

git submodule init
git submodule update

Then, start a localhost HTTP server, for example,

python -m SimpleHTTPServer 8009

Test with local fake OAuth endpoint

Point your browser to http://localhost:8009/test/?localtest=true to start testing. You will need to disable popup blocker to properly run the interactive testcases.

Test with the real Google OAuth endpoint

Point your browser to to start testing. You will need to disable popup blocker to properly run the interactive testcases.

Writing tests

You will find all the information you need to write testcases on the QUnit and Sinon.JS website. All code submission are expected to accompany with testcases.

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