dart - Making Private Route in Flutter

Question

How can I make a wrapper over my private routes, which navigate to screen only when user is authorized, otherwise redirect to login and get back to the original screen after login. How can make this in a generalized way, so that I just reuse it on my other Private future screens?

Answer 1

If you are using routes parameter in your MaterialApp, you can replace it with following implementation

import 'dart:collection';

import 'package:flutter/widgets.dart';

class ConditionalRouter extends MapMixin<String, WidgetBuilder> {
  final Map<String, WidgetBuilder> public;
  final Map<String, WidgetBuilder> private;

  ConditionalRouter({this.public, this.private});

  @override
  WidgetBuilder operator [](Object key) {
    if (public.containsKey(key))
      return public[key];
    if (private.containsKey(key)) {
      if (MyAuth.isUserLoggedIn)
        return private[key];
      // Adding next page parameter to your Login page
      // will allow you to go back to page, that user were going to
      return (context) => LoginPage(nextPage: key);
    }
    return null;
  }

  @override
  void operator []=(key, value) {}

  @override
  void clear() {}

  @override
  Iterable<String> get keys {
    final set = Set<String>();
    set.addAll(public.keys);
    set.addAll(private.keys);
    return set;
  }

  @override
  WidgetBuilder remove(Object key) {
    return public[key] ?? private[key];
  }
}

And use it like that:

MaterialApp(
  // ...
  routes: ConditionalRouter(
    public: {
      '/start_page': (context) => StartPage()
    },
    private: {
      '/user_profile': (context) => UserProfilePage()
    }
  )
)