Build Runner Flutter

If you're a Flutter developer, you may have come across the term "build runner" before. In this post, we'll explore what it is, how it works, and how you can use it to optimize your Flutter app development process.

What is Build Runner?

Build runner is a command-line tool included in the Flutter SDK that enables you to run code generation and other tasks as part of your app's build process. When you run flutter run or flutter build, build runner can automatically run tasks like building and compiling code, generating source code files, and running tests.

Build runner comes with a variety of built-in runners, which are tasks that can be executed as part of the build process. For example, the flutter packages pub run build_runner build command will run the build runner, which generates static files for your Flutter web app.

How Does Build Runner Work?

Build runner works by scanning your Flutter project for code annotations and other metadata that indicate which tasks should be run during the build process. Once these annotations are discovered, build runner executes the corresponding runners to perform the specified tasks.

For example, let's say you're using the json_serializable library to create JSON serialization and deserialization code for your Dart classes. To generate the code, you can add a @JsonSerializable annotation to your class, like so:

import 'package:json_annotation/json_annotation.dart';

@JsonSerializable()
class MyClass {
  final int id;
  final String name;

  MyClass({required this.id, required this.name});

  factory MyClass.fromJson(Map<String, dynamic> json) =>
      _$MyClassFromJson(json);

  Map<String, dynamic> toJson() => _$MyClassToJson(this);
}

With this annotation in place, you can use the flutter packages pub run build_runner build command to generate the JSON serialization and deserialization code automatically.

How Can You Use Build Runner to Optimize Your App Development Process?

Build runner can be a powerful tool for optimizing your Flutter app development process. Here are a few tips for getting the most out of build runner:

• Use annotations to automate code generation tasks, like JSON serialization and deserialization, database access code, and more
• Take advantage of build runner's caching features to speed up the build process
• Use the watch runner to automatically rebuild your app when changes are made to your code
• Leverage third-party build runners to automate tasks like code formatting, linting, and more

Conclusion

In conclusion, build runner is a versatile and powerful tool for any Flutter developer. By allowing you to automate code generation and other tasks as part of the build process, it can help you streamline your development workflow and focus on what matters most: building great apps.