Built Value

https://pub.dev/packages/built_value
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Built Value is a Dart code generation library that provides immutable value types, enum classes, and...
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### Example pubspec.yaml Dependency

Source: https://pub.dev/packages/built_value/install

This is an example of how the built_value dependency will appear in your pubspec.yaml file.

```yaml
dependencies:
  built_value: ^8.12.6
```

--------------------------------

### Define a Serializable Person Class with Built Value

Source: https://pub.dev/packages/built_value_generator

This example demonstrates how to define a Dart class using `built_value` for JSON serialization. It uses the `@BuiltValueField` annotation to map JSON keys to Dart member variables and includes a `BuiltList` for hobbies.

```dart
import 'package:built_value/built_value.dart';
import 'package:built_value/serializer.dart';
import 'package:built_collection/built_collection.dart';

part 'person.g.dart';

abstract class Person implements Built<Person, PersonBuilder> {
  static Serializer<Person> get serializer => _$personSerializer;

  int get id;

  int? get age;

  @BuiltValueField(wireName: 'first_name')
  String? get firstName;

  BuiltList<String> get hobbies;

  Person._();
  factory Person([void Function(PersonBuilder) updates]) = _$Person;
}
```

--------------------------------

### Process a Field Before Instantiation with Built Value Hook

Source: https://pub.dev/packages/built_value_generator

Utilize the `@BuiltValueHook(finalizeBuilder: true)` annotation to execute custom logic just before a builder is finalized and the value is created. This example sorts a list of items.

```dart
abstract class MyValue {
  @BuiltValueHook(finalizeBuilder: true)
  static void _sortItems(MyValueBuilder b) =>
      b..items.sort();

```

--------------------------------

### Generate Built Value Types with build_runner

Source: https://pub.dev/packages/built_value_generator

Use `dart run build_runner build` for one-off builds or `dart run build_runner watch` to continuously update generated output when source files change. Requires `built_value_generator` and `build_runner` as dev dependencies.

```bash
dart run build_runner build
```

```bash
dart run build_runner watch
```

--------------------------------

### Boilerplate for Value Types

Source: https://pub.dev/packages/built_value_generator

This live template from IntelliJ can be used to generate the basic structure for a value type class. You only need to manually enter the data class name.

```dart
abstract class $CLASS_NAME$ implements Built<$CLASS_NAME$, $CLASS_NAME$Builder> {
  $CLASS_NAME$._();
  factory $CLASS_NAME$([void Function($CLASS_NAME$Builder) updates]) = _$$$CLASS_NAME$;
}

```

--------------------------------

### Add built_value to Flutter Project

Source: https://pub.dev/packages/built_value/install

Use this command to add built_value as a dependency in a Flutter project.

```bash
$ flutter pub add built_value
```

--------------------------------

### Add built_value to Dart Project

Source: https://pub.dev/packages/built_value/install

Use this command to add built_value as a dependency in a Dart project.

```bash
$ dart pub add built_value
```

--------------------------------

### Add built_value_generator to Flutter Project

Source: https://pub.dev/packages/built_value_generator/install

Use this command to add the package as a dev dependency in a Flutter project.

```bash
flutter pub add built_value_generator
```

--------------------------------

### Add built_value_generator to Dart Project

Source: https://pub.dev/packages/built_value_generator/install

Use this command to add the package as a dev dependency in a Dart project.

```bash
dart pub add built_value_generator
```

--------------------------------

### Import built_value_generator in Dart Code

Source: https://pub.dev/packages/built_value_generator/install

Import the necessary library into your Dart files to use its functionalities.

```dart
import 'package:built_value_generator/built_value_generator.dart';
```

--------------------------------

### Import built_value in Dart Code

Source: https://pub.dev/packages/built_value/install

Include this import statement in your Dart files to use the built_value library.

```dart
import 'package:built_value/built_value.dart';
```

--------------------------------

### Validate a Field on Instantiation

Source: https://pub.dev/packages/built_value_generator

Use the private constructor of a value class to perform arbitrary checks on fields when an instance is created. This ensures data integrity by throwing an `ArgumentError` if a condition is not met.

```dart
abstract class MyValue {
  MyValue._() {
    if (field < 0) {
      throw ArgumentError(field, 'field', 'Must not be negative.');
    }
  }

```

--------------------------------

### Set Default Field Values on Builder Creation

Source: https://pub.dev/packages/built_value_generator

Employ the `@BuiltValueHook(initializeBuilder: true)` annotation to run a hook when a builder is initialized. This allows setting default values for fields, ensuring they have a predictable state.

```dart
abstract class MyValue {
  @BuiltValueHook(initializeBuilder: true)
  static void _setDefaults(MyValueBuilder b) =>
      b
        ..name = 'defaultName'
        ..count = 0;

```

--------------------------------

### Dart Static Analysis Warning

Source: https://pub.dev/packages/built_value/score

This code snippet shows a static analysis warning related to variable naming conventions in Dart. It indicates that the variable name 'Map' is not in lowerCamelCase.

```dart
  Iterable<Object?> serialize(Serializers serializers, Map Map,

```
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