3.2 KiB
auth_oauth2
package:angel_auth
strategy for OAuth2 login, i.e. Facebook or Github.
Usage
First, create an options object:
configureServer(Angel app) async {
// Load from a Map, i.e. app config:
var opts = new AngelOAuth2Options.fromJson(map);
// Create in-place:
const AngelAuthOAuth2Options OAUTH2_CONFIG = const AngelAuthOAuth2Options(
callback: '<callback-url>',
key: '<client-id>',
secret: '<client-secret>',
authorizationEndpoint: '<authorization-endpoint>',
tokenEndpoint: '<access-token-endpoint>');
}
After getting authenticated against the remote server, we need to be able to identify
users within our own application. Use an OAuth2Verifier
to associate remote users
with local users.
/// You might use a pure function to create a verifier that queries a
/// given service.
OAuth2Verifier oauth2verifier(Service userService) {
return (oauth2.Client client) async {
var response = await client.get('https://api.github.com/user');
var ghUser = JSON.decode(response.body);
var id = ghUser['id'];
Iterable<Map> matchingUsers = await userService.index({
'query': {'githubId': id}
});
if (matchingUsers.isNotEmpty) {
// Return the corresponding user, if it exists
return User.parse(matchingUsers.firstWhere((u) => u['githubId'] == id));
} else {
// Otherwise,create a user
return await userService.create({'githubId': id}).then(User.parse);
}
};
}
Now, initialize an OAuth2Strategy
, using the options and verifier.
You'll also need to provide a name for this instance of the strategy.
Consider using the name of the remote authentication provider (ex. facebook
).
configureServer(Angel app) {
// ...
var oauthStrategy =
new OAuth2Strategy('github', OAUTH2_CONFIG, oauth2Verifier(app.service('users')));
}
Lastly, connect it to an AngelAuth
instance, and wire it up to an Angel
server.
Set up two routes:
- Redirect users to the external provider
- Acts as a callback and handles an access code
In the case of the callback route, you may want to display an HTML page that closes
a popup window. In this case, use confirmPopupAuthentication
, which is bundled with
package:angel_auth
, as a callback
function:
configureServer(Angel app) async {
// ...
var auth = new AngelAuth();
auth.strategies.add(oauth2Strategy);
// Redirect
app.get('/auth/github', auth.authenticate('github'));
// Callback
app.get('/auth/github/callback', auth.authenticate(
'github',
new AngelAuthOptions(callback: confirmPopupAuthentication())
));
// Connect the plug-in!!!
await app.configure(auth);
}
Custom Scope Delimiter
This package should work out-of-the-box for most OAuth2 providers, such as Github or Dropbox.
However, if your OAuth2 scopes are separated by a delimiter other than the default (' '
),
you can add it in the AngelOAuth2Options
constructor:
configureServer(Angel app) async {
const AngelOAuth2Options OPTS = const AngelOAuth2Options(
// ...
delimiter: ','
);
}