angular – 如何将formGroup添加到另一个formGroup

Reuse components in angular2 model driven forms

但我希望能够像这样将新的formGroups添加到页面的不同区域.

<form [formGroup]="myForm">
  <!--... other inputs -->
  <md-tab-group formGroupName="nutrition">
    <md-tab formGroupName="calories">
      <template md-stretch-tabs="always" md-tab-label>Calories</template>
      <template md-tab-content>
        <calories></calories> <!-- I want to add controll groups like this-->
      </template>
    </md-tab>
    <md-tab formGroupName="carbs">
      <template md-stretch-tabs="always" md-tab-label>Carbs</template>
      <template md-tab-content>
        <carbs></carbs>
      </template>
    </md-tab>
  </md-tab-group>
</form>

整个表单模型应如下所示：

{
   name: '',nutrition:{
      calories: {
        @R_421_10586@l: ''
        // more
      },carbs: {
        @R_421_10586@l: ''
        // more
      }
}

我已经能够像这样添加营养formGroup：

< nutrition [parentForm] =“myForm”>< / nutrition>

import { Component,OnInit,Input } from '@angular/core';
import { FormGroup,FormControl,FormBuilder,Validators } from '@angular/forms';

@Component({
  SELEctor: 'nutrition',template: `
  <div [formGroup]="parentForm"></div>
  `
})
export class NutritionComponent implements OnInit {

    @input() parentForm: FormGroup;

    nutritionGroup: FormGroup;

    constructor(private _fb: FormBuilder) {
    }

    ngOnInit() {
      this.nutritionGroup = new FormGroup({
        blank: new FormControl('',Validators.required)
      });
      this.parentForm.addControl('nutrition',this.nutritionGroup);
    }
}

但我无法弄清楚如何将营养形式组传递给卡路里formGroup,如下所示：

< calories [parentControl] =“营养”>< / calories>

import { Component,Validators } from '@angular/forms';

@Component({
  SELEctor: 'calories',template: ``
})
export class CaloriesComponent implements OnInit {

  @input() parentControl: FormGroup;
  caloriesForm: FormGroup;

  constructor(private _fb: FormBuilder) {  }
  ngOnInit(){
    this.caloriesForm = new FormGroup({
        blank: new FormControl('',Validators.required)
      });

    this.parentControl.addControl('calories',this.caloriesForm);
  }
}

可以这样做吗？