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> 
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# Method name:

authentication.onLogin(handler: OnLoginHandler)

# Method Link:

https://dev.wix.com/docs/sdk/host-modules/site/authentication/on-login.md

# Method Description:

Registers a callback function to be called when a member logs in.

Use this function to run code after a member successfully logs in, such as updating the UI, loading member-specific data,
or tracking login events.

# Method Permissions:



# Method Permissions Scopes IDs:

undefined



# Method Code Examples:

## Subscribe to login events


```javascript
```typescript
import { onLogin } from '@wix/authentication';

const unsubscribe = onLogin(() => {
  console.log('Member logged in');
  // Update UI to show member content
  document.getElementById('memberGreeting').style.display = 'block';
});

// Later, to stop listening:
// unsubscribe();
```
```

## Track login events and clean up on component unmount


```javascript
```typescript
import { onLogin, onLogout } from '@wix/authentication';

function initAuthTracking() {
  const unsubscribeLogin = onLogin(() => {
    console.log('Login event tracked');
    // Send analytics event
  });

  const unsubscribeLogout = onLogout(() => {
    console.log('Logout event tracked');
    // Send analytics event
  });

  // Return cleanup function
  return () => {
    unsubscribeLogin();
    unsubscribeLogout();
  };
}
```
```