将firebase添加到flutter web时出现问题，TypeError：无法读取未定义的属性（读取“应用程序”）
Posted
技术标签:
【中文标题】将firebase添加到flutter web时出现问题，TypeError：无法读取未定义的属性（读取“应用程序”）【英文标题】：Problem adding firebase to flutter web, TypeError: Cannot read properties of undefined (reading 'app') 【发布时间】：2021-11-03 19:25:42 【问题描述】：我正在尝试将 firebase 添加到将用于 android 和 web 的颤振项目中*** 和其他任何地方，但没有什么对我有用，不知道我错过了什么。
在我的pubspec.yaml中添加的包
dependencies:
...
firebase_core: ^1.6.0
firebase_storage: ^10.0.3
cloud_firestore: ^2.5.1
main.dart
中的 Firebase 应用初始化main() async
WidgetsFlutterBinding.ensureInitialized();
Firebase.initializeApp();
runApp(MyApp());
index.html 文件
<body>
<script src="https://www.gstatic.com/firebasejs/9.0.1/firebase-app.js"></script>
<script src="https://www.gstatic.com/firebasejs/9.0.1/firebase-storage.js"></script>
<script src="https://www.gstatic.com/firebasejs/9.0.1/firebase-firestore.js"></script>
<script type="module">
import getAnalytics from "https://www.gstatic.com/firebasejs/9.0.1/firebase-analytics.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
// For Firebase JS SDK v7.20.0 and later, measurementId is optional
const firebaseConfig =
apiKey: "XXXXXXXXXXXXXXXXX",
authDomain: "XXXXXXXXXXXXX",
projectId: "XXXXXXXXXXXX",
storageBucket: "XXXXXXXXXXXX",
messagingSenderId: "XXXXXXXXXX",
appId: "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX",
measurementId: "XXXXXXXX"
;
// Initialize Firebase
firebase.initializeApp(firebaseConfig);
const analytics = getAnalytics(app);
</script>
<!-- This script installs service_worker.js to provide PWA functionality to
application. For more information, see:
https://developers.google.com/web/fundamentals/primers/service-workers -->
<script>
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 && (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>
当我开始调试时，我在 web_entrypoint.dart 文件中得到了这个异常
TypeError: Cannot read properties of undefined (reading 'app')
at Object.app$ [as app] (http://localhost:59554/packages/firebase_core_web/src/interop/core.dart.lib.js:31:101)
at new cloud_firestore_web.FirebaseFirestoreWeb.new (http://localhost:59554/packages/cloud_firestore_web/src/write_batch_web.dart.lib.js:819:64)
at Function.registerWith (http://localhost:59554/packages/cloud_firestore_web/src/write_batch_web.dart.lib.js:731:73)
at Object.registerPlugins (http://localhost:59554/packages/PROJECT_NAME/generated_plugin_registrant.dart.lib.js:20:46)
at main (http://localhost:59554/web_entrypoint.dart.lib.js:31:35)
at main.next (<anonymous>)
at runBody (http://localhost:59554/dart_sdk.js:37422:34)
at Object._async [as async] (http://localhost:59554/dart_sdk.js:37453:7)
at main$ (http://localhost:59554/web_entrypoint.dart.lib.js:30:18)
at http://localhost:59554/main_module.bootstrap.js:19:10
at Array.forEach (<anonymous>)
at window.$dartRunMain (http://localhost:59554/main_module.bootstrap.js:18:32)
at <anonymous>:1:8
at Object.runMain (http://localhost:59554/dwds/src/injected/client.js:8825:21)
at http://localhost:59554/dwds/src/injected/client.js:22713:19
at _wrapJsFunctionForAsync_closure.$protected (http://localhost:59554/dwds/src/injected/client.js:3851:15)
at _wrapJsFunctionForAsync_closure.call$2 (http://localhost:59554/dwds/src/injected/client.js:11063:12)
【问题讨论】：
【参考方案1】：在 index.html 中使用 8.6.1 版本而不是这个：
https://www.gstatic.com/firebasejs/9.0.1/firebase-storage.js
将此用于所有 9.0.1 库
【讨论】：
以上是关于将firebase添加到flutter web时出现问题，TypeError：无法读取未定义的属性（读取“应用程序”）的主要内容，如果未能解决你的问题，请参考以下文章
添加 firebase 后构建 Flutter apk 时出现 Gradle 错误
当我为flutter web添加firebase时，我的应用程序将无法运行
在android studio中将firebase添加到flutter时出错：插件项目：firebase_core_web未找到。请更新 settings.gradle [重复]