StreamBuilder Explained | Flutter for Web Developers

What’s StreamBuilder?

The StreamBuilder class is a widget that builds itself based on the latest snapshot of interaction with a Stream. It is essential for managing asynchronous data in Flutter applications. Key properties include ‘stream’, which connects to the asynchronous computation, and ‘builder’, which defines how to build the widget based on the current snapshot.

Check the official documentation for more.

StreamBuilder explained for Web Developers

From a web developer’s perspective, the StreamBuilder class is similar to React’s useEffect or Angular’s Observables, where it listens for data changes and re-renders the UI accordingly. Unlike traditional APIs that fetch data once, StreamBuilder continuously listens to a stream of data, allowing for real-time updates in the UI.

Example Code

Here is an example of how to use StreamBuilder:

StreamBuilder<int>(
  stream: myStream,
  builder: (BuildContext context, AsyncSnapshot<int> snapshot) {
    if (snapshot.connectionState == ConnectionState.waiting) {
      return CircularProgressIndicator();
    } else if (snapshot.hasError) {
      return Text('Error: ${snapshot.error}');
    } else {
      return Text('Latest value: ${snapshot.data}');
    }
  },
);

StreamBuilder Remarks

The StreamBuilder class is a powerful tool for Flutter developers, enabling them to create responsive applications that react to real-time data changes seamlessly.