Не удается связать веб-приложение flutter с проектом firebase / бесконечная загрузка

# #firebase #flutter #dart #google-cloud-firestore #flutter-web

Вопрос:

У меня проблема, когда я пытаюсь связать свой веб-проект Flutter с моей Firebase. Я добавляю элементы, импорт и SDK, и когда я касаюсь main.dart для инициализации функций firebase, даже если код не показывает никаких ошибок, когда я запускаю приложение из своей IDE с помощью Google, я сталкиваюсь с бесконечным экраном загрузки. А иногда даже нет синей панели загрузки. Все SDK, моя IDE и мои фреймворки обновлены в стабильной версии.

Я настроил проект firebase только с этим приложением и инициализировал базу данных firestore, как я видел в CRUD, за которым я следил.

ссылка на CRUD: https://www.youtube.com/watch?v=Ue_dIKOMcb4amp;t=1009s

Но я не думаю, что это происходит из проекта, потому что я даже не могу инициализировать Firebase в новом приложении flutter counter по умолчанию.

И в моем index.HTML , в параграфе конфигурации firebase мой ключ API подчеркнут КРАСНЫМ

Возможно, я использую неправильный метод для инициализации функций Firebase в моем проекте, поэтому, пожалуйста, кто-нибудь может показать мне, как это сделать.

Вот мой pubspec.yaml :

 name: flutter_web_diary
description: A new Flutter project.

version: 1.0.0 1

environment:
  sdk: ">=2.6.0 <3.0.0"

dependencies:
  flutter:
    sdk: flutter
  provider: ^4.0.4
  firebase_core: "^1.7.0"
  cloud_firestore: "^2.5.3"

  cupertino_icons: ^0.1.2

dev_dependencies:
  flutter_test:
    sdk: flutter

flutter:
  uses-material-design: true

 

Мой idex.HTML :

 <!DOCTYPE html>
<html lang="en">
<head>
  <!--
    If you are serving your web app in a path other than the root, change the
    href value below to reflect the base path you are serving from.

    The path provided below has to start and end with a slash "/" in order for
    it to work correctly.

    For more details:
    * https://developer.mozilla.org/en-US/docs/Web/HTML/Element/base

    This is a placeholder for base href that will be replaced by the value of
    the `--base-href` argument provided to `flutter build`.
  -->
  <base href="$FLUTTER_BASE_HREF">

  <meta charset="UTF-8">
  <meta content="IE=Edge" http-equiv="X-UA-Compatible">
  <meta name="description" content="A new Flutter project.">

  <!-- iOS meta tags amp; icons -->
  <meta name="apple-mobile-web-app-capable" content="yes">
  <meta name="apple-mobile-web-app-status-bar-style" content="black">
  <meta name="apple-mobile-web-app-title" content="flutter_application_1">
  <link rel="apple-touch-icon" href="icons/Icon-192.png">

  <title>flutter_application_1</title>
  <link rel="manifest" href="manifest.json">
</head>
<body>
  
  <script>
    import { initializeApp } from "firebase/app";
    import { } from "https://www.gstatic.com/firebasejs/9.1.3/firebase-app.js"
    import { } from "https://www.gstatic.com/firebasejs/9.1.3/firebase-firestore.js"
// TODO: Add SDKs for Firebase products that you want to use
// https://firebase.google.com/docs/web/setup#available-libraries

// Your web app's Firebase configuration
    const firebaseConfig = {
      apiKey: "...",
      authDomain: "...",
      databaseURL: "...",
      projectId: "...",
      storageBucket: "...",
      messagingSenderId: "...",
      appId: "..."
    };

// Initialize Firebase
const app = initializeApp(firebaseConfig);
  // Initialize Firebase
  firebase.initializeApp(firebaseConfig);
    var serviceWorkerVersion = null;
    var scriptLoaded = false;
    function loadMainDartJs() {
      if (scriptLoaded) {
        return;
      }
      scriptLoaded = true;
      var scriptTag = document.createElement('script');
      scriptTag.src = 'main.dart.js';
      scriptTag.type = 'application/javascript';
      document.body.append(scriptTag);
    }

    if ('serviceWorker' in navigator) {
      // Service workers are supported. Use them.
      window.addEventListener('load', function () {
        // Wait for registration to finish before dropping the <script> tag.
        // Otherwise, the browser will load the script multiple times,
        // potentially different versions.
        var serviceWorkerUrl = 'flutter_service_worker.js?v='   serviceWorkerVersion;
        navigator.serviceWorker.register(serviceWorkerUrl)
          .then((reg) => {
            function waitForActivation(serviceWorker) {
              serviceWorker.addEventListener('statechange', () => {
                if (serviceWorker.state == 'activated') {
                  console.log('Installed new service worker.');
                  loadMainDartJs();
                }
              });
            }
            if (!reg.active amp;amp; (reg.installing || reg.waiting)) {
              // No active web worker and we have installed or are installing
              // one for the first time. Simply wait for it to activate.
              waitForActivation(reg.installing || reg.waiting);
            } else if (!reg.active.scriptURL.endsWith(serviceWorkerVersion)) {
              // When the app updates the serviceWorkerVersion changes, so we
              // need to ask the service worker to update.
              console.log('New service worker available.');
              reg.update();
              waitForActivation(reg.installing);
            } else {
              // Existing service worker is still good.
              console.log('Loading app from service worker.');
              loadMainDartJs();
            }
          });

        // If service worker doesn't succeed in a reasonable amount of time,
        // fallback to plaint <script> tag.
        setTimeout(() => {
          if (!scriptLoaded) {
            console.warn(
              'Failed to load app from service worker. Falling back to plain <script> tag.',
            );
            loadMainDartJs();
          }
        }, 4000);
      });
    } else {
      // Service workers not supported. Just drop the <script> tag.
      loadMainDartJs();
    }
  </script>
</body>
</html>
 

и мой main.dart :

 import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:flutter/material.dart';
import 'package:flutter_web_diary/diary_card.dart';
import 'package:flutter_web_diary/diary_entry_model.dart';
import 'package:flutter_web_diary/top_bar_title.dart';
import 'package:provider/provider.dart';

import 'diary_entry_page.dart';

// Import the firebase_core plugin
import 'package:firebase_core/firebase_core.dart';

Future<void> main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await Firebase.initializeApp();
  runApp(MyApp());
}

/// We are using a StatefulWidget such that we only create the [Future] once,
/// no matter how many times our widget rebuild.
/// If we used a [StatelessWidget], in the event where [App] is rebuilt, that
/// would re-initialize FlutterFire and make our application re-enter loading state,
/// which is undesired.
class App extends StatefulWidget {
  // Create the initialization Future outside of `build`:
  @override
  _AppState createState() => _AppState();
}

class _AppState extends State<App> {
  /// The future is part of the state of our widget. We should not call `initializeApp`
  /// directly inside [build].
  final Future<FirebaseApp> _initialization = Firebase.initializeApp();

  @override
  Widget build(BuildContext context) {
    return FutureBuilder(
      // Initialize FlutterFire:
      future: _initialization,
      builder: (context, snapshot) {
        // Check for errors
        if (snapshot.hasError) {
          return Text(snapshot.error.toString());
        }

        // Once complete, show your application
        if (snapshot.connectionState == ConnectionState.done) {
          return MyApp();
        }

        // Otherwise, show something whilst waiting for initialization to complete
        return CircularProgressIndicator();
      },
    );
  }
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    // Refer to https://firebase.flutter.dev

    final diaryCollection = FirebaseFirestore.instance.collection('diaries');
    final diaryStream = diaryCollection.snapshots().map((snapshot) {
      return snapshot.docs.map((doc) => DiaryEntry.fromDoc(doc)).toList();
    });
    return StreamProvider<List<DiaryEntry>>(
      create: (_) => diaryStream,
      child: MaterialApp(
        title: 'My Diary',
        debugShowCheckedModeBanner: false,
        theme: ThemeData(
          colorScheme: ColorScheme.fromSwatch(primarySwatch: Colors.indigo).copyWith(secondary: Colors.pink),
        ),
        initialRoute: '/',
        routes: {
          '/': (context) => MyHomePage(),
          '/new-entry': (context) => DiaryEntryPage.add(),
        },
      ),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key, this.title}) : super(key: key);

  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  @override
  Widget build(BuildContext context) {
    final diaryEntries = Provider.of<List<DiaryEntry>>(context);
    return Scaffold(
      appBar: AppBar(
        bottom: PreferredSize(
          preferredSize: Size.fromHeight(94.0),
          child: TopBarTitle('Diary Entries'),
        ),
        elevation: 0,
      ),
      body: Center(
        child: SizedBox(
          width: MediaQuery.of(context).size.width * 3 / 5,
          child: ListView(
            children: <Widget>[
              SizedBox(height: 40),
              if (diaryEntries != null)
                for (var diaryData in diaryEntries)
                  DiaryCard(diaryEntry: diaryData),
              if (diaryEntries == null)
                Center(child: CircularProgressIndicator()),
            ],
          ),
        ),
      ),
      floatingActionButtonLocation: FloatingActionButtonLocation.endTop,
      floatingActionButton: FloatingActionButton(
        elevation: 1.5,
        onPressed: () => Navigator.of(context).pushNamed('/new-entry'),
        tooltip: 'Add To Do',
        child: Icon(Icons.add),
        backgroundColor: Theme.of(context).colorScheme.secondary,
      ),
    );
  }
}
 

Ответ №1:

Для firebase в web есть другой пакет. Пожалуйста, проверьте это Firebase_core_web

Комментарии:

1. Я проверил, но я не вижу, что мне нужно изменить в коде после импорта пакета

2. firebase.flutter.dev/docs/installation/web

Ответ №2:

Хорошо, я просто изменил способ инициализации своего проекта в моем main.dart

Вот так:

 void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await Firebase.initializeApp();
  runApp(App());
}
 

вместо этого:

 Future<void> main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await Firebase.initializeApp();
  runApp(MyApp());
}
 

И я перевел свою базу данных firestore в тестовый режим.