How to Fix NoSuchMethodError When Using FutureBuilder with Flutter Dart

Learn how to resolve the `NoSuchMethodError` in Flutter when using `FutureBuilder` with a list of data from SQFlite, and how to properly handle your JSON data with custom classes.
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How to Fix NoSuchMethodError When Using FutureBuilder with Flutter Dart

When working with Flutter and Dart, especially with asynchronous data fetch scenarios like retrieving messages from a local SQLite database using SQFlite, developers can encounter a variety of issues. One particularly common problem is the NoSuchMethodError when attempting to use a FutureBuilder. In this post, we'll explain why this error occurs and how to fix it effectively.

Understanding the Problem

The error you may encounter typically looks something like this:

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The Solution

Instead of trying to call messageToJson on the entire list, we need to operate on the individual Message instances. Below are the steps to modify your code accordingly.

Step 1: Adjust the FutureBuilder

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

Step 2: Review Your Message Class

Ensure that your Message class properly defines how to convert from and to JSON. The implementation you have seems correct. Here's a quick reminder of what it looks like:

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

Step 3: Make Sure Your Database Query Returns a List

Lastly, ensure your getMessages method correctly returns a list of Message objects. The current implementation appears correct.

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

Conclusion

By ensuring that you access the messages as a list of Message instances rather than trying to apply a method that doesn't exist on a list, you can effectively eliminate the NoSuchMethodError. This technique not only resolves the immediate issue but also better organizes your data handling within your Flutter application. Happy coding!