Simple_auth: The Simplest way to Authenticate in F...

Most apps need to make API calls. Every API needs authentication, yet no developer wants to deal with authentication. Simple Auth embeds authentication into the API so you dont need to deal with it.

This is a port of Clancey.SimpleAuth for Dart and Flutter

The network/api part including the generator was based off of Chopper by Hadrien Lejard

iOS:

Android:

Providers

Current Built in Providers

Azure Active Directory
Amazon
Dropbox
Facebook
Github
Google
Linked In
Microsoft Live Connect
Keycloak
And of course any standard OAuth2/Basic Auth server.

var api = new simpleAuth.GoogleApi(
      "google", "client_id",clientSecret: "clientSecret",
      scopes: [
        "https://www.googleapis.com/auth/userinfo.email",
        "https://www.googleapis.com/auth/userinfo.profile"
      ]);
var request = new Request(HttpMethod.Get, "https://www.googleapis.com/oauth2/v1/userinfo?alt=json");
var userInfo = await api.send<UserInfo, UserInfo>(request);

That's it! If the user is not logged in, they will automatically be prompted. If their credentials are cached from a previous session, the api call proceeds! Expired tokens even automatically refresh.

Call SimpleAuthFlutter.init(); in your Main.Dart. Now Simple Auth can automatically present your login UI

Google requires the following redirect: com.googleusercontent.apps.YOUR_CLIENT_ID

Simple Auth by default uses SFSafari on iOS and Chrome Tabs on Android.

This means normal http redirects cannot work. You will need to register a custom scheme for your app as a redirect. For most providers, you can create whatever you want. i.e. com.myapp.foo:/redirct

Android Manifest

you would then add the following to your Android manifest

<activity android:name="clancey.simpleauth.simpleauthflutter.SimpleAuthCallbackActivity" >
    <intent-filter android:label="simple_auth">
        <action android:name="android.intent.action.VIEW" />
        <category android:name="android.intent.category.DEFAULT" />
        <category android:name="android.intent.category.BROWSABLE" />
        <data android:scheme="com.myapp.foo" />
    </intent-filter>
</activity>

For instagram, the above won't work, as it will only accept redirect URIs that start with https. Add the following instead:

    <activity android:name="clancey.simpleauth.simpleauthflutter.SimpleAuthCallbackActivity">

      <intent-filter>
        <action android:name="android.intent.action.VIEW" />

        <category android:name="android.intent.category.DEFAULT" />
        <category android:name="android.intent.category.BROWSABLE" />

        <data android:scheme="http" />
        <data android:scheme="https" />
        <data android:host="myflutterapp.com" />
      </intent-filter>
    </activity>

iOS & macOS

on iOS you need something like the following as your AppDelegate.m file under the Runner folder

#include "AppDelegate.h"
#include "GeneratedPluginRegistrant.h"
#import <Flutter/Flutter.h>
#import <simple_auth_flutter/SimpleAuthFlutterPlugin.h>

@implementation AppDelegate

- (BOOL)application:(UIApplication *)application
    didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
  [GeneratedPluginRegistrant registerWithRegistry:self];
  // Override point for customization after application launch.
  return [super application:application didFinishLaunchingWithOptions:launchOptions];
}

- (BOOL)application:(UIApplication *)app openURL:(NSURL *)url options:(NSDictionary<UIApplicationOpenURLOptionsKey,id> *)options{
    return [SimpleAuthFlutterPlugin checkUrl:url];
}

- (BOOL)application:(UIApplication *)application openURL:(NSURL *)url sourceApplication:(NSString *)sourceApplication annotation:(id)annotation{
    return [SimpleAuthFlutterPlugin checkUrl:url];
}

@end

On macOS:

import Cocoa
import FlutterMacOS
import simple_auth_flutter

@NSApplicationMain
class AppDelegate: FlutterAppDelegate {
  override func applicationShouldTerminateAfterLastWindowClosed(_ sender: NSApplication) -> Bool {
    return true
  }

    override func applicationDidFinishLaunching(_ notification: Notification) {
        let appleEventManager:NSAppleEventManager = NSAppleEventManager.shared()
        appleEventManager.setEventHandler(self, andSelector: #selector(AppDelegate.handleGetURLEvent(event:replyEvent:)), forEventClass: AEEventClass(kInternetEventClass), andEventID: AEEventID(kAEGetURL))

    }

    @objc func handleGetURLEvent(event: NSAppleEventDescriptor, replyEvent: NSAppleEventDescriptor) {
        let urlString = event.paramDescriptor(forKeyword: AEKeyword(keyDirectObject))?.stringValue!
        let url = URL(string: urlString!)!
        SimpleAuthFlutterPlugin.check(url);
    }
}

For iOS 11/macOS 10.15 and higher, you don't need to do anything else. On older versions the following is required in the info.plist

    <key>CFBundleURLTypes</key>
    <array>
        <dict>
            <key>CFBundleURLSchemes</key>
            <array>
                <string>com.myapp.foo</string>
            </array>
            <key>CFBundleURLName</key>
            <string>myappredirect</string>
        </dict>
    </array>

Note, if you want to avoid Apples mandatory user consent dialog

"foo" Wants to use "bar.com" to Sign In
This allows the app and website to share information about you.

add the lines above and set FooAuthenticator.useSSO = false; which will not use SFAuthenticationSession on iOS, and ASWebAuthenticationSession on macOS. This is the default behavior for the Keycloak provider.

Json objects will automatically serialize if you conform to JsonSerializable

If you use the generator and you objects have the factory factory JsonSerializable.fromJson(Map<String, dynamic> json) your api calls will automatically Serialize/Deserialize

Or you can pass your own Converter to the api and handle conversion yourself.

Dart

pub run build_runner build

flutter

flutter packages pub run build_runner build

Add the following to your pubspec.yaml

dev_dependencies:
  simple_auth_generator:
  build_runner: ^0.8.0

The Generator is not required, however it will make things magical.

@GoogleApiDeclaration("GoogleTestApi","client_id",clientSecret: "client_secret", scopes: ["TestScope", "Scope2"])
abstract class GoogleTestDefinition {
  @Get(url: "https://www.googleapis.com/oauth2/v1/userinfo?alt=json")
  Future<Response<GoogleUser>> getCurrentUserInfo();
}

will generate a new Api for you that is easy to use!

var api = new GoogleTestApi("google");
var user = await api.getCurrentUserInfo();

For more examples, check out the example project

Thanks for the logo made by @iqbalhood

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