Flutter代码生成插件mix_generator的使用

Flutter代码生成插件mix_generator的使用

mix_generator 是一个用于在 Mix 包中生成 Spec 和 Dto 类的插件。它通过根据注解类自动生成必要的代码来简化 Spec 和 Dto 类的创建。

安装

要使用 mix_generator，你需要在 pubspec.yaml 文件中添加以下依赖项：

dependencies:
  mix: ^0.0.0
  mix_annotations: ^0.0.0

dev_dependencies:
  build_runner: ^0.0.0
  mix_generator: ^0.0.0

然后运行以下命令以安装这些依赖项：

flutter pub get

使用

MixableSpec

[@MixableSpec](/user/MixableSpec)() 注解用于生成可混合的类。下面是一个示例：

import 'package:mix/mix.dart';
import 'package:mix_annotations/mix_annotations.dart';

part 'my_spec.g.dart';

[@MixableSpec](/user/MixableSpec)()
final class MySpec extends Spec<MySpec> with _$MySpec {
  final String? name;
  final int? age;

  const MySpec({this.name, this.age});
}

选项

• withCopyWith - 默认为 true，生成 copyWith 方法。
• withEquality - 默认为 true，生成相等性方法。
• withLerp - 默认为 true，生成 lerp 方法。
• skipUtility - 默认为 false，跳过实用类。
• prefix - 默认为 Spec 类名，为生成的类添加前缀。

MixableDto

@MixableDto() 注解用于生成可混合的 Dto。下面是一个示例：

import 'package:mix/mix.dart';
import 'package:mix_annotations/mix_annotations.dart';

part 'value_dto.g.dart';

@MixableDto()
final class ValueDto<Value> extends Dto<Value> with _$MyDto {
  final String? name;
  final int? age;

  const ValueDto({this.name, this.age});
}

选项

• mergeLists - 默认为 true，就地合并列表。
• generateUtility - 默认为 true，生成实用类。
• generateValueExtension - 默认为 true，生成将 Value 转换为 Dto 的值扩展，通过 toDto() 扩展。

MixableProperty

[@MixableProperty](/user/MixableProperty)() 注解用于指定用于代码生成的可混合属性。下面是一个示例：

import 'package:mix_generator/mix_generator.dart';

[@MixableProperty](/user/MixableProperty)(
  dto: MixableFieldDto(type: BoxConstraintsDto),
  utilities: [
    MixableUtility(
      properties: [
        (path: 'minWidth', alias: 'minWidth'),
        (path: 'maxWidth', alias: 'maxWidth'),
      ],
    ),
  ],
)
final BoxConstraints? constraints;

MixableUtility

@MixableUtility() 注解用于指定用于代码生成的可混合实用工具。下面是一个示例：

import 'package:mix_generator/mix_generator.dart';

[@MixableProperty](/user/MixableProperty)(
  utilities: MixableUtility(
    type: BoxDecoration,
    properties: [
      (path: 'color', alias: 'color'),
      (path: 'border', alias: 'border'),
      (path: 'borderRadius', alias: 'borderRadius'),
    ],
  ),
)
final Decoration? decoration;

代码生成

为了生成你的可混合类和 Dto 的代码，运行以下命令：

flutter pub run build_runner build

示例代码

// ignore_for_file: prefer_relative_imports, avoid-importing-entrypoint-exports, camel_case_types
import 'package:flutter/material.dart';
import 'package:mix/mix.dart';
import 'package:mix_annotations/mix_annotations.dart';

part 'box_spec.g.dart';

const _constraints = MixableUtility(
  type: BoxConstraints,
  properties: [
    (path: 'minWidth', alias: 'minWidth'),
    (path: 'maxWidth', alias: 'maxWidth'),
    (path: 'minHeight', alias: 'minHeight'),
    (path: 'maxHeight', alias: 'maxHeight'),
  ],
);

const _foreground = MixableUtility(type: BoxDecoration);
const _boxDecor = MixableUtility(
  type: BoxDecoration,
  properties: [
    (path: 'color', alias: 'color'),
    (path: 'border', alias: 'border'),
    (path: 'border.directional', alias: 'borderDirectional'),
    (path: 'borderRadius', alias: 'borderRadius'),
    (path: 'borderRadius.directional', alias: 'borderRadiusDirectional'),
    (path: 'gradient', alias: 'gradient'),
    (path: 'gradient.sweep', alias: 'sweepGradient'),
    (path: 'gradient.radial', alias: 'radialGradient'),
    (path: 'gradient.linear', alias: 'linearGradient'),
    (path: 'boxShadows', alias: 'shadows'),
    (path: 'boxShadow', alias: 'shadow'),
    (path: 'elevation', alias: 'elevation'),
  ],
);

const _shapeDecor = MixableUtility(
  alias: 'shapeDecoration',
  type: ShapeDecoration,
);

[@MixableSpec](/user/MixableSpec)()
final class BoxSpec extends Spec<BoxSpec> with _$BoxSpec {
  /// {[@macro](/user/macro) box_spec_of}
  static const of = _$BoxSpec.of;

  static const from = _$BoxSpec.from;

  /// Aligns the child within the box.
  final AlignmentGeometry? alignment;

  /// Adds empty space inside the box.
  final EdgeInsetsGeometry? padding;

  /// Adds empty space around the box.
  final EdgeInsetsGeometry? margin;

  /// Applies additional constraints to the child.
  [@MixableProperty](/user/MixableProperty)(utilities: [_constraints])
  final BoxConstraints? constraints;

  /// Paints a decoration behind the child.
  [@MixableProperty](/user/MixableProperty)(utilities: [_boxDecor, _shapeDecor])
  final Decoration? decoration;

  /// Paints a decoration in front of the child.
  [@MixableProperty](/user/MixableProperty)(utilities: [_foreground])
  final Decoration? foregroundDecoration;

  /// Applies a transformation matrix before painting the box.
  final Matrix4? transform;

  /// Aligns the origin of the coordinate system for the [transform].
  final AlignmentGeometry? transformAlignment;

  /// Defines the clip behavior for the box
  /// when [BoxConstraints] has a negative minimum extent.
  final Clip? clipBehavior;

  /// Specifies the width of the box.
  final double? width;

  /// Specifies the height of the box.
  final double? height;

  const BoxSpec({
    this.alignment,
    this.padding,
    this.margin,
    this.constraints,
    this.decoration,
    this.foregroundDecoration,
    this.transform,
    this.transformAlignment,
    this.clipBehavior,
    this.width,
    this.height,
    super.animated,
  });
}