How to iterate form array(array in array in array) in angular2 reactive forms?

问题

I tried to Iterate formArray several times,

This is plunker link for this case https://plnkr.co/edit/4kiJF7cL5VKwn3KnvjvK?p=preview

i want out put like this plunk https://plnkr.co/edit/zg6nbFULl0WlTZ1sVn5h?p=preview

This is my scenario

[

{
  "id": 1,
  "legend": "businessModule",
  "group": [

    {
      "id": 1,
      "permission": {
        "controleType": "ff",
        "id": 2,
        "key": "create Business"
      },
      "roles": [
        {
          "id": 1,
          "name": "self"
        },
        {
          "id": 2,
          "name": "other"
        }
      ]
    },


    {
      "id": 1,
      "permission": {
        "controleType": "ff",
        "id": 2,
        "key": "edit business"
      },
      "roles": [
        {
          "id": 1,
          "name": "self"
        },
        {
          "id": 2,
          "name": "other"
        }
      ]
    }

  ]
},


{
  "id": 2,
  "legend": "PanicModule",
  "group": [

    {
      "id": 1,
      "permission": {
        "controleType": "ff",
        "id": 2,
        "key": "create panic"
      },
      "roles": [
        {
          "id": 1,
          "name": "self"
        },
        {
          "id": 2,
          "name": "other"
        }
      ]
    },


    {
      "id": 1,
      "permission": {
        "controleType": "ff",
        "id": 2,
        "key": "edit panic"
      },
      "roles": [
        {
          "id": 1,
          "name": "self"
        },
        {
          "id": 2,
          "name": "other"
        }
      ]
    }

  ]
}

];

For above array I tried to build reactive forms , I need checkboxes for permission, roles array under group

So I tried to iterate array like this

component.ts

validateForm() {
  this.roleForm = this.fb.group({
  roleName: ['', Validators.required],
  roleDescription: ['', Validators.required],
  permissionModules: this.fb.array([])
  });
   this.initModule()
 }

initModule() {

  const contractArray = <FormArray>this.roleForm.controls['permissionModules'];
  console.log(contractArray, 'contractArray')
   this.form_objects.forEach(element => {
       this.newElement = element;
       console.log(this.newElement, 'this.newElement')
    // element.forEach(group => {

          contractArray.push(this.fb.group({
            id: [''],
            legend:this.newElement.legend,
            group: this.fb.array([ ])
       }));
    // }
  this.initGroup(element, contractArray)
   }
}



 initGroup (element, contractArray) {
    console.log(element, '@@@@@@@@@@@@@@@@@@@@@@',contractArray)
   // const groupArray = <FormArray>contractArray.controls['group'];
    this.groupArray = <FormArray>this.roleForm.controls.permissionModules.controls[1];

    console.log(this.groupArray, 'groupArray&&&&&&&')
      element.group.forEach(group => {
       this.newGroup = group;
       console.log(this.newGroup, 'this.newGroup')
      /* if(typeof (this.groupArray) !== 'undefined') {
           this.groupArray.push(this.fb.group({
                id: [''],
                legend:this.newGroup.legend

        }));
       }*/

        }
      }

 submit(value) {
    this.result = value
}

My html is like

 <form [formGroup]="roleForm"  (submit)="submit(roleForm.value)">
    <h3>Add trust</h3>

    <div class="form-group">
        <label>Name</label>
        <input type="text" class="form-control" formControlName="roleName">
    </div>

    <div class="form-group">
        <label>roleDescription</label>
        <input type="text" class="form-control" formControlName="roleDescription">
    </div>
     <div class="form-group">
        <label>permission roles</label>
        <div formArrayName="permissionModules">
          <div *ngFor="let contract of roleForm.controls.permissionModules.controls;
          let i=index" class="panel panel-default">
           <div  [formGroupName]="i">
               {{contract.value.legend}}
             <!-- <input type = "checkbox" formControlName="legend">
              {{contract.value.legend}}-->



           </div>


          </div>
        </div>

     </div>
   <button type="submit">Submit</button>

</form>

But I am unable to iterate the second level array in above case under initGroup () function groupArray, I didn' t know what is my mistake, I searched many sites all are telling only one level iteration, I am new to angular2 ,So Please any one help me Thanks in advance