如何设置输入角度的默认值？

Question

我在组件中有输入：

  @Input() applicant: Applicant;

interface Applicant {
   applicant: ApplicantItem,
   representative: Representative
}

模板是：

<div *ngIf="applicant.representative.type></div>

问题是，如果< code >申请人没有对象< code >代表，申请就会失败。

如果没有代表，如何设置默认值？

这样地：

@Input() applicant: Applicant = <Applicant>{};

我需要始终有< code >类型的< code >代表。

这里还介绍了如何避免错误:

applicant.representative = adapt(applicant.representative);

Answer 1

可以通过为@Input指定setter和getter来实现:

@Input() 
set applicant(applicant: Applicant) {
    this._applicant = applicant || { applicant: null, representative: null };
}
get applicant(): Applicant {
    return this._applicant;
}

private _applicant: Applicant;

Answer 2

你可以试试这个

@Input() applicant = function(applicant : Applicant  = {applicant:null, representative:nul}){
    console.log(applicant)
  }

Answer 3

在这里检查值是否未定义，如果是，则设置默认值

@Input() applicant: Applicant;

ngOnInIt() {
    if (!this.applicant) {
      this.applicant = {
          // ur defaults here
      };
}

如果希望始终将正确的值从父组件传递给子组件，则

this.applicants.map((applicant) => {
     if (!applicant || !applicant.representative) {
      applicant = {
        // your defaults here
      };
      this.representativeAdapter.adapt(applicant.representative);
      ...