Flutter实体生成插件squarealfa_entity_generator的使用

Flutter实体生成插件squarealfa_entity_generator的使用

获取开始

验证

首先，在你想要生成验证代码的PODO（Plain Old Dart Object）类上添加@validatable注解：

/// 确保库中包含part语句。
part 'recipe.g.dart';

@validatable
class Recipe {

    final String title;

    const Recipe({required this.title});
}

这将生成一个Validator类，其中包含每个属性的验证方法。默认情况下，每个验证方法会返回null，例如：

/// 这是一个生成的验证器类的示例。
class RecipeValidator implements Validator {
  const RecipeValidator();

  ValidationError? validateTitle(String value) {
    return null;
  }

  @override
  ErrorList validate(covariant Recipe entity) {
    var errors = <ValidationError>[];
    ValidationError? error;
    if ((error = validateTitle(entity.title)) != null) {
      errors.add(error!);
    }

    return ErrorList(errors);
  }

  @override
  void validateThrowing(covariant Recipe entity) {
    var errors = validate(entity);
    if (errors.validationErrors.isNotEmpty) throw errors;
  }
}

为每个字段添加规则注解，以应用于该字段：

/// 确保库中包含part语句。
part 'ingredient.g.dart';

@validatable
class Ingredient {

  @StringLength(minLength: 10)
  final String description;

  @StringLength(maxLength: 10)
  final String? notes;

  @StringLength(minLength: 2)
  final String? tag;

  @DoubleRange(minValue: 10, maxValue: 20)
  final double quantity;

  @Range(minValue: 10)
  final Decimal precision;

  @Range(minValue: 10, maxValue: 20)
  final int intQuantity;

  @Range(minValue: 10, maxValue: 20)
  final int? nintQuantity;

  @Range(minValue: 10, maxValue: 20)
  @required
  final int? rInt;

  Ingredient({
    required this.description,
    required this.quantity,
    required this.precision,
    required this.intQuantity,
    this.notes,
    this.tag,
    this.nintQuantity,
    this.rInt,
  });
}

构建器

在PODO类上添加@builder注解以生成非不可变构建器类：

/// 确保库中包含part语句。
part 'recipe.g.dart';

@builder
class Recipe {
  final String title;

  final String? description;
  
  Recipe({
    required this.title,
    this.description,
  });
}

这将生成一个构建器类：

class RecipeBuilder implements Builder<Recipe> {
  String title;
  String? description;

  RecipeBuilder({
    required this.title,
    this.description,
  });

  factory RecipeBuilder.fromRecipe(Recipe entity) {
    return RecipeBuilder(
      title: entity.title,
      description: entity.description,
    );
  }

  @override
  Recipe build() {
    var entity = Recipe(
      title: title,
      description: description,
    );
    RecipeValidator().validateThrowing(entity);
    return entity;
  }
}

copyWith

在PODO类上添加@copyWith注解以生成包含copyWith方法的扩展：

/// 确保库中包含part语句。
part 'recipe.g.dart';

@copyWith
class Recipe {
  final String title;

  final String? description;
  
  Recipe({
    required this.title,
    this.description,
  });
}

这将生成一个扩展，该扩展添加了copyWith方法：

extension RecipeCopyWithExtension on Recipe {
  Recipe copyWith({
    String? title,
    String? description,
    bool setDescriptionToNull = false,
  }) {
    return Recipe(
      title: title ?? this.title,
      description:
          setDescriptionToNull ? null : description ?? this.description,
    );
  }
}