我有一个超类,它是许多子类(Customer, Product, ProductCategory…)的父类(Entity)。
我想在Typescript中动态克隆一个包含不同子对象的对象。
例如:拥有不同产品的客户拥有一个ProductCategory
var cust:Customer = new Customer ();
cust.name = "someName";
cust.products.push(new Product(someId1));
cust.products.push(new Product(someId2));
为了克隆对象的整个树,我在实体中创建了一个函数
public clone():any {
var cloneObj = new this.constructor();
for (var attribut in this) {
if(typeof this[attribut] === "object"){
cloneObj[attribut] = this.clone();
} else {
cloneObj[attribut] = this[attribut];
}
}
return cloneObj;
}
当new被转译为javascript时,将引发以下错误:错误TS2351:不能对缺少调用或构造签名的表达式使用'new'。
虽然脚本工作,但我想摆脱转译错误
下面是一个现代的实现,它也解释了Set和Map:
export function deepClone<T extends object>(value: T): T {
if (typeof value !== 'object' || value === null) {
return value;
}
if (value instanceof Set) {
return new Set(Array.from(value, deepClone)) as T;
}
if (value instanceof Map) {
return new Map(Array.from(value, ([k, v]) => [k, deepClone(v)])) as T;
}
if (value instanceof Date) {
return new Date(value) as T;
}
if (value instanceof RegExp) {
return new RegExp(value.source, value.flags) as T;
}
return Object.keys(value).reduce((acc, key) => {
return Object.assign(acc, { [key]: deepClone(value[key]) });
}, (Array.isArray(value) ? [] : {}) as T);
}
尝试一下:
deepClone({
test1: { '1': 1, '2': {}, '3': [1, 2, 3] },
test2: [1, 2, 3],
test3: new Set([1, 2, [1, 2, 3]]),
test4: new Map([['1', 1], ['2', 2], ['3', 3]])
});
test1:
1: 1
2: {}
3: [1, 2, 3]
test2: Array(3)
0: 1
1: 2
2: 3
test3: Set(3)
0: 1
1: 2
2: [1, 2, 3]
test4: Map(3)
0: {"1" => 1}
1: {"2" => 2}
2: {"3" => 3}