带有嵌套表单数组的角反应表单

我是Angular 2的新手，因此决定最好的学习方法是阅读Angular官方指南。

我阅读了《反应式指南》https://angular.io/guide/reactive-forms

演示链接：https : //stackblitz.com/angular/jammvmbrpxle

虽然内容总体来说还不错，但我仍坚持如何实现更复杂的表单。在给定的示例中，每个英雄都有很多地址的潜力。地址本身就是一个平面对象。

如果地址中包含其他信息，例如地址中房间的颜色和类型，该怎么办？

export class Address {
    street = '';
    city   = '';
    state  = '';
    zip    = '';
    rooms = Room[];
}

export class Room {
     type = '';
}

这样表单模型将如下所示...

createForm() {
this.heroForm = this.fb.group({
  name: '',
  secretLairs: this.fb.array([
      this.fb.group({
          street: '',
          city: '',
          state: '',
          zip: '',
          rooms: this.fb.array([
              this.fb.group({
                 type: ''
          })]),
      })]),
  power: '',
  sidekick: ''
});

}

编辑-与ngOnChanges一起使用的完成代码

hero-detail.component.ts

createForm() {
    this.heroForm = this.fb.group({
      name: '',
      secretLairs: this.fb.array([
        this.fb.group({
          street: '',
          city: '',
          state: '',
          zip: '',
          rooms: this.fb.array([
            this.fb.group({
              type: ''
            })
          ])
        })
      ]),
      power: '',
      sidekick: ''
    });
  }

  ngOnChanges() {
    this.heroForm.reset({
      name: this.hero.name,
    });
    this.setAddresses(this.hero.addresses);
  }

  setAddresses(addresses: Address[]) {
    let control = this.fb.array([]);
    addresses.forEach(x => {
      control.push(this.fb.group({
        street: x.street,
        city: x.city,
        state: x.state,
        zip: x.zip,
        rooms: this.setRooms(x) }))
    })
    this.heroForm.setControl('secretLairs', control);
  }

  setRooms(x) {
    let arr = new FormArray([])
    x.rooms.forEach(y => {
      arr.push(this.fb.group({ 
        type: y.type 
      }))
    })
    return arr;
  }

hero-detail.component.html（嵌套表单数组部分）

<div formArrayName="secretLairs" class="well well-lg">
  <div *ngFor="let address of heroForm.get('secretLairs').controls; let i=index" [formGroupName]="i" >
    <!-- The repeated address template -->
    <h4>Address #{{i + 1}}</h4>
    <div style="margin-left: 1em;">
      <div class="form-group">
        <label class="center-block">Street:
          <input class="form-control" formControlName="street">
        </label>
      </div>
      <div class="form-group">
        <label class="center-block">City:
          <input class="form-control" formControlName="city">
        </label>
      </div>
      <div class="form-group">
        <label class="center-block">State:
          <select class="form-control" formControlName="state">
            <option *ngFor="let state of states" [value]="state">{{state}}</option>
          </select>
        </label>
      </div>
      <div class="form-group">
        <label class="center-block">Zip Code:
          <input class="form-control" formControlName="zip">
        </label>
      </div>
    </div>
    <br>
    <!-- End of the repeated address template -->
    <div formArrayName="rooms" class="well well-lg">
      <div *ngFor="let room of address.get('rooms').controls; let j=index" [formGroupName]="j" >
          <h4>Room #{{j + 1}}</h4>
          <div class="form-group">
            <label class="center-block">Type:
              <input class="form-control" formControlName="type">
            </label>
          </div>
      </div>
    </div>
  </div>
  <button (click)="addLair()" type="button">Add a Secret Lair</button>
</div>