I am experiencing an issue with Firebase Hosting of my Flutter App.
I have set up Firebase Hosting like described in the Documentation. When I deploy the Project with this firebase.json – file it works like intended.
...
"hosting": {
"public": "build/web",
"ignore": [
"firebase.json",
"**/.*",
"**/node_modules/**"
],
"frameworksBackend": {
"region": "europe-west1"
}
...
To make URLs like <Hosting-Domain>/download accessible, I have to add a rewrite, like this:
...
"hosting": {
"public": "build/web",
"ignore": [
"firebase.json",
"**/.*",
"**/node_modules/**"
],
"frameworksBackend": {
"region": "europe-west1"
},
"rewrites": [
{
"source": "**",
"destination": "/index.html"
}
]
},
...
When I deploy the Project with the rewrite, it works fine emulated locally with the Firebase Emulator Suite, but when in open the Website online, a blank Page is displayed. The Console displays this Messages:
> Rejecting promise with error: FormatException: SyntaxError: Unexpected token '<', "<html>
<h"... is not valid JSON
> Uncaught (in promise) null
The FormatException apparently refers to my Index.html-file which looks like this:
<!DOCTYPE html>
<html>
<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="/">
<meta charset="UTF-8">
<meta content="IE=Edge" http-equiv="X-UA-Compatible">
<meta name="description" content="A new Flutter project.">
<!-- iOS meta tags & 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_2">
<link rel="apple-touch-icon" href="icons/Icon-192.png">
<!-- Favicon -->
<link rel="icon" type="image/png" href="favicon.png"/>
<title>flutter_application_2</title>
<link rel="manifest" href="manifest.json">
</head>
<body>
<script src="flutter_bootstrap.js" async></script>
<script type="module">
// Import the functions you need from the SDKs you need
import { initializeApp } from "https://www.gstatic.com/firebasejs/10.12.2/firebase-app.js";
import { getAnalytics } from "https://www.gstatic.com/firebasejs/10.12.2/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 = {
// My Firebase-Config
};
// Initialize Firebase
const app = initializeApp(firebaseConfig);
const analytics = getAnalytics(app);
</script>
</body>
</html>
Ways I tried to fix this Error:
- Altered the base href in Index.html to
"$FLUTTER_BASE_HREF"or“./” - Changed
"public": "build/web"in firebase.json to"source": "."and similar combinations - Set up an new Project step-by-step (adding dependencies, source code, …), this failed at the same Step like this
- Altered the rewrite statement in firebase.json (different statement, Redirect, …): rewrite is necessary, only fails with rewrite
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