HarmonyOS-User-Authentication-Guide

Hey folks! Today, let's talk about some crucial user authentication operations in HarmonyOS app development, especially functions like signing out, deleting accounts, and re-authentication that can sometimes be confusing. Grab your snacks and drinks, let's dive in!

1. An Elegant Way to Sign Out Users When a user wants to switch accounts or leave your app, you can't just close it abruptly. Try this super useful signOut() method:

import { auth } from '@kit/accountIdKit';

// Call this when the sign-out button is tapped
auth.signOut()
.then(() => {
console.log("Goodbye! Local cache cleared.");
// You can navigate to the login page here
})
.catch((error) => {
console.log("Oops, sign-out failed", error);
// Show a toast to prompt the user to check their network connection
});
Key Points:

It automatically clears the token and user information after sign-out.
Calling it when the user is not signed in will result in an error (remember to check the login status first).
Operations requiring a token, like Cloud DB access, will become invalid immediately.

1. The Serious Business of Account Deletion ⚠️ This operation is like "deleting your account and running away," so make sure to have a confirmation step in your UI! Here's the core code:

auth.deleteUser()
.then(() => {
console.log("Account has been wiped from existence.");
// Clear local data + navigate to the welcome page
})
.catch((error) => {
if (error.code === 2022) { // Error code that requires re-authentication
this.reAuthAndDelete(); // Trigger the re-authentication flow
}
});
A Realistic Scenario:

User taps the "Delete Account" button.
A modal pops up saying, "Are you sure you want to leave us? QAQ"
User confirms, triggering the deletion.
If the account has a history of sensitive operations, it might require password re-entry for verification.

1. Re-authentication for Critical Moments When a user performs a sensitive action (like changing a payment password), the system might suddenly require them to sign in again. This is where you use reauthenticate:

// Example with password verification
auth.reauthenticate({
credential: {
authType: auth.AuthType.PASSWORD,
password: "user_entered_password" // Remember to handle encryption!
}
}).then(() => {
console.log("Identity verified. Proceed with your operation.");
}).catch((error) => {
console.log("Authentication failed", error);
// Show the reason for failure, e.g., too many incorrect password attempts
});
Multiple Authentication Methods Supported:

Phone verification code
Email verification
Third-party accounts (WeChat, QQ, etc.)
Biometrics (fingerprint/face)

1. Practical Pitfall Guide Don't panic when you run into issues. Try these common solutions:

Q1: Why can I still get user info after calling signOut()?

Check if there are multiple caches that haven't been cleared.
Wait for the async operation to complete before navigating (try adding a setTimeout).
Q2: How should user data be handled after account deletion?

Inform users in advance that their cloud data will be deleted.
Retain important data for a 7-day transition period (as required by law).
Q3: Re-authentication always returns error 2022?

Check the network connection status.
Confirm if the credential has expired (e.g., the validity period of an SMS code).
Call auth.getCurrentUser() to check the current user's status.
Q4: How to design a user-friendly authentication flow?

Provide clear error messages (don't just say "Operation failed").
Offer alternative verification methods.
Implement humane account locking after repeated errors (don't ban them forever).

1. A Heart-to-Heart Honestly, the most challenging part of the authentication module isn't the code, but handling all the edge cases. I recommend that you:

Wrap sensitive operations in try-catch blocks.
Add timeout handling to all network requests.
Keep local logs of critical operations (for easier debugging).
Always test biometrics on a real device!
Finally, here's our "lifesaver kit":

Official Troubleshooting Guide: Click here
Error Code Quick Reference: Teleport
Developer Community Entrance: Poke me
Don't panic if you get stuck, feel free to drop a comment and chat with us anytime. Happy coding, fewer bugs, and more slacking off! (Just kidding... or am I?)

【Class dismissed!】🚀