Скачать или смотреть Fixing the Flutter StreamBuilder UI Not Updating with Firestore Data

Discover how to effectively resolve the issue of the Flutter StreamBuilder not updating UI when listening to changes in a Firestore document. Follow our clear solution step-by-step!
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This video is based on the question https://stackoverflow.com/q/77726159/ asked by the user 'Pratyush' ( https://stackoverflow.com/u/21825978/ ) and on the answer https://stackoverflow.com/a/77787348/ provided by the user 'Pratyush' ( https://stackoverflow.com/u/21825978/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

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Why Is My Flutter StreamBuilder Not Updating?

If you are developing with Flutter and you are using Firestore as your database, you may encounter an issue where your StreamBuilder is not updating the UI as expected when listening to changes in a single Firestore document.

The Issue

In a typical application using StreamBuilder, you may design it to show different widgets based on whether there's data available or not. However, some developers face a problem where upon receiving new data, the StreamBuilder continues to show the initial widget instead of updating to reflect the changes.

This was the case with a user who observed that the StreamBuilder would render Widget2 (indicating no data) initially, but after the data was received, it failed to update to Widget1 that reflects the current state based on the data fetched from Firestore.

Example Implementation

Here’s a simplified version of what they had implemented:

[[See Video to Reveal this Text or Code Snippet]]

The Logs

The logs showed erroneous behavior, indicating that the Flutter framework was correctly fetching the data but not rebuilding the UI accordingly.

The Solution

It turns out the problem stemmed from an animation library used in conjunction with the StreamBuilder widget.

Key Takeaway

When working with animated widgets inside the StreamBuilder, it’s essential to be cautious. The preferred approach is to limit the use of animation widgets when conditionally rendering based on the snapshot data.

Correcting the Code

Initially, the code had something like this:

[[See Video to Reveal this Text or Code Snippet]]

This can create issues where changes in the data do not allow the UI to refresh properly.

Updated Example

Instead, it should simply be:

[[See Video to Reveal this Text or Code Snippet]]

Why This Works

By modifying your code to only utilize the animation widget for the data-present state and replacing the widget for the no-data state with a simple Text widget unwrapped from animations, you eliminate conflicts that might cause the UI to stutter or fail to rebuild properly.

Conclusion

In summary, when dealing with StreamBuilder in Flutter, especially with animated components, always ensure you conditionally render widgets without nesting too many animated widgets that could interfere with the Flutter rebuild process. Adjusting your implementation can significantly resolve UI update issues while providing a responsive and polished user experience.

For developers encountering similar issues, try adhering to this best practice, and your UI should update seamlessly as expected!