通过工厂创建密钥/值对只允许类中的属性和相关的属性值。

Question

所以如果我说是car

public class Car 
{
  ManufacturedYear: number;
  Manufacturer: string;
}

我希望能够构建一个强类型的标准树(它将被序列化为json和用于过滤的用户客户端或SQL子句的服务器端)。以下是我到目前为止所拥有的：

export class FilterFactory {
  private constructor() {
  }

  public static createFilter<TModel, TKey extends keyof TModel>(
    key: TKey,
    value: TModel[TKey],
  ): IFilterCriteria<TModel, TKey> {
    return new FilterCriteria(key, value);
  }
}

export interface IFilterCriteria<TModel, TKey extends keyof TModel> {
  property?: TKey;
  value?: TModel[TKey];
  operator? : 'and' | 'or';  //tbd enum
  criterias?: ?? 
}

class FilterCriteria<TModel, TKey extends keyof TModel>
  implements IFilterCriteria<TModel, TKey>
{
  public property?: TKey;
  public value?: TModel[TKey];
  public operator? : 'and' | 'or';  //tbd enum
  public criterias?: ?? 

  constructor() {}
}

Codepen示例

因此，以下工作：

var noerror = FilterFactory.createFilter<Car, 'ManufacturedYear'>('ManufacturedYear', 2008);

var expectederror = FilterFactory.createFilter<Car, 'ManufacturedYear'>('ManufacturedYear', 'asdf');

我无法理解的是，如何消除为泛型和参数指定键的冗余。因此，我的代码将是以下代码之一：

var noerror = FilterFactory.createFilter<Car, 'ManufacturedYear'>(2008);
// or
var noerror = FilterFactory.createFilter<Car>('ManufacturedYear', 2008);

Answer 1

不像我所希望的那样优雅，但它并不坏，它至少是可读的：

TLDR：

class Car {
  ManufacturedYear: number;
  Manufacturer: string;
}

const manuYearFilter = FilterFactory.with<Car>().create("ManufacturedYear", 2009);

执行情况：

export interface IFilter {
}

export class FilterFactory<TModel> {
  private constructor() {
  }

  public  create<TKey extends keyof TModel>(
    key: TKey,
    value: TModel[TKey],
  ): IFilter {
    return new Filter(key, value);
  }

  public static with<TModel>() {
    return new FilterFactory<TModel>();
  }
}

class Filter<TModel, TKey extends keyof TModel>
  implements IFilter
{
  constructor(
    public property: TKey,
    public value: TModel[TKey],
  ) {
  }
}