how to create collapsible/expandable/ Tree structure with checkbox list using angular 6 & bootstrap 3.3.7

Question

here i am trying for the collapsible/ tree structure with checkbox on parent & children also but i wasnt able to create it exactly i was able to create till unordered list from the json

{
  "properties": {
    "host": {
      "fields": {
        "keyword": {
          "ignore_above": 256,
          "type": "keyword"
        }
      },
      "type": "text",
      "fielddata": true
    },
    "information": {
      "properties": {
        "filetype": {
          "fields": {
            "keyword": {
              "ignore_above": 256,
              "type": "keyword"
            }
          },
          "type": "text",
          "fielddata": true
        },
        "author": {
          "fields": {
            "keyword": {
              "ignore_above": 256,
              "type": "keyword"
            }
          },
          "type": "text",
          "fielddata": true
        },
        "authorcountry": {
          "fields": {
            "keyword": {
              "ignore_above": 256,
              "type": "keyword"
            }
          },
          "type": "text",
          "fielddata": true
        }
      }
    },
    "url": {
      "fields": {
        "keyword": {
          "ignore_above": 256,
          "type": "keyword"
        }
      },
      "type": "text",
      "fielddata": true
    },
    "name": {
      "fields": {
        "keyword": {
          "ignore_above": 256,
          "type": "keyword"
        }
      },
      "type": "text",
      "fielddata": true
    },
    "instrument": {
      "properties": {
        "Style": {
          "fields": {
            "keyword": {
              "ignore_above": 256,
              "type": "keyword"
            }
          },
          "type": "text",
          "fielddata": true
        },
        "instrumentCode": {
          "type": "integer"
        },
        "instrumentName": {
          "type": "text"
        },
        "instrumentNumber": {
          "fields": {
            "keyword": {
              "ignore_above": 256,
              "type": "keyword"
            }
          },
          "type": "text",
          "fielddata": true
        }

      }
    }
  }
}

.html code

<button class="btn btn-primary" (click)="getData()">getData</button>


<h1>ul element</h1>

<hr>

 <ul class="list-group"   *ngFor="let x of inf | keyvalue">
    <li class="list-group-item">{{x.key}}</li>
    <ng-container *ngIf="x.value.hasOwnProperty('properties')">
      <ul *ngFor="let y of x.value.properties | keyvalue">
      <li>
        {{y.key}}
      </li>
      </ul>  
    </ng-container> 
  </ul>

collapsible /tree structure

below is my stackblitz link

https://stackblitz.com/edit/angular-k5tdpe

i can try plugins also but the input data format for the plugins was different angular2-tree plugin & ng2 -tree /ngx-tree so any suggestions

Answer 1

just add a input type check and use [(ngModel)]

<ul class="list-group"   *ngFor="let x of inf | keyvalue">
    <li class="list-group-item">
     <!--add a input type checkbox and relation with x.check-->
     <input type="checkbox" [(ngModel)]="x.check">
     {{x.key}}</li>
    <!---change the *ngIf to add the x.check condition-->
    <ng-container *ngIf="x.check && x.value.hasOwnProperty('properties')">
      <ul *ngFor="let y of x.value.properties | keyvalue">
      <li>
        {{y.key}}
      </li>
      </ul>  
    </ng-container> 
  </ul>

Updated if you want a "recursive component" its easy. I put an example, you can see the result in stackblitz

Basically a "recursive component is a component that in template has the same component. Typically we use a json model with properties children (yes, you can transform your "complex" json in some that has properties an children) If one time you create a jsondata with children, your json is like, e.g. like

data = [{
    title: "uno", children: [
      { title: "uno-uno" }]
  },
  {
    title: "dos", children: [
      { title: "dos-uno",children: [
           { title: "dos-uno" }
           ]},
      { title: "dos-dos" }]
  }
  ]

We can have a app.component like

  <li *ngFor="let item of data">
     <app-li [title]="item.title" [children]="item.children"></app-li>
  </li>

And our app-li like

<li (click)="check=!check">
      <div [className]="children?check?'arrow-down':'arrow-up':'arrow-right'"></div>
      {{title}}
</li>
<ul *ngIf="children && check">
  <ng-container *ngFor="let item of children">
       <app-li [title]="item.title" [children]="item.children"></app-li>
  </ng-container>
</ul>

See that we feed the app-li with "children"

NOTE:I add a < div> with className to "simulate" the triangles

Updated 2 We can pass the own item itselft

The component becomes like

@Component({
  selector: 'app-li',
  template: `<li >
              <div (click)="check=!check" [className]="item.children?
                   check?'arrow-down':'arrow-up':'arrow-right'">
              </div>
              <input type="checkbox" [(ngModel)]="item.select" >
              <span (click)="check=!check">{{item.title}}</span>
              </li>
             <ul *ngIf="item.children && check">
             <ng-container *ngFor="let item of item.children">
               <app-li [item]="item" ></app-li>
               </ng-container>
             </ul>
  `,
    styleUrls: [ './hello.component.css' ]



})
export class HelloComponent  {
  @Input() item: any;
}

And the app

<li *ngFor="let item of data">
     <app-li [item]="item" ></app-li>
</li>

See stackblitz forked