Realtime Database Event Types
value
- The value event type is triggered whenever the data at a specified path in the real–time database changes, providing the current snapshot of the data at that path.
- This event is useful for fetching the initial state of the data and for listening to changes in the entire contents of a specific path
Example: Listening for value Changes
firebase.database().ref('users/1').on('value', function(snapshot) {
var data = snapshot.val();
console.log("New data:", data);
});
Output
- Executing the above code will continuously listen for changes to the data at the path /users/1 in the Realtime Database and log the new data whenever it changes.
- child_added, child_changed, child_removed.
- These event types are triggered when a new child is added, an existing child is changed, or a child is removed from the specified path, respectively.
Firebase Event Types
Firebase provides event types such as value, child_added, onSnapshot, and onAuthStateChanged across its services like Realtime Database, Cloud Firestore and Authentication. These event types enable developers to build real-time applications and trigger actions based on changes in data or authentication state.
In this article, We will learn about these event types are essential for creating dynamic and interactive applications with Firebase in detail.