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I was trying to create dynamic tree view component in angular 4. I have an array which have the data to form the dynamic tree view.

I tried to create a custom directive to achieve this. Here is my code :

import { Directive,ElementRef, Input, HostListener } from '@angular/core';

@Directive({
  selector: '[appTreeView]'
})
export class TreeViewDirective {

  @Input('appTreeView') categories:any;
  @Input() config:any = {
    categoryList: null,
    children : [],
    nodeLabel : '',
    treeId : '1',
    nodeId : '12'
  };
  elRef: any;
  constructor(el: ElementRef) {
    console.log(Element);
    console.log(this.config);
    console.log(this.categories);
    this.elRef = el;
  }

  ngOnInit(){
    console.log('input : ',this.categories);
    this.elRef.nativeElement.innerHTML = '<ul>' +
    '<li *ngFor="let node in ' + this.categories + '; let indx = index">' +
      '<i class="collapsed" data-ng-show="node.' + this.config.children + '.length && node.collapsed" data-ng-click="' + this.config.treeId + '.selectNodeHead(node)"></i>' +
      '<i class="expanded" data-ng-show="node.' + this.config.children + '.length && !node.collapsed" data-ng-click="' + this.config.treeId + '.selectNodeHead(node)"></i>' +
      '<i class="normal" data-ng-hide="node.' + this.config.children + '.length"></i> ' +
      '<span data-ng-class="node.selected" data-ng-click="selectNodeLabel(node)">{{node.' + this.config.nodeLabel + '}}</span>' +
      '<div data-ng-hide="node.collapsed" data-tree-id="' + this.config.treeId + '" data-tree-model="node.' + this.config.children + '" data-node-id=' + this.config.nodeId + ' data-node-label=' + this.config.nodeLabel + ' data-node-children=' + this.config.children + '></div>' +
    '</li>' +
  '</ul>';
  }


}

In my component html :

<div [appTreeView]="categoryListArray"></div>

In component ts :

import { Component, OnInit } from '@angular/core';

@Component({
  selector: 'app-tree-view-test',
  templateUrl: './tree-view-test.component.html',
  styleUrls: ['./tree-view-test.component.css']
})
export class TreeViewTestComponent implements OnInit {

  categoryListArray:any = [];
  constructor() { }

  ngOnInit() {
    this.categoryListArray = [
      { "label" : "User", "id" : "role1", "children" : [
        { "label" : "subUser1", "id" : "role11", "children" : [] },
        { "label" : "subUser2", "id" : "role12", "children" : [
          { "label" : "subUser2-1", "id" : "role121", "children" : [
            { "label" : "subUser2-1-1", "id" : "role1211", "children" : [] },
            { "label" : "subUser2-1-2", "id" : "role1212", "children" : [] }
          ]}
        ]}
      ]},
      { "label" : "Admin", "id" : "role2", "children" : [] },
      { "label" : "Guest", "id" : "role3", "children" : [] }
    ];
  }

  onCategoryClick(event){
    console.log('clicked item : ', event);
  }

}

Here is the output how am getting :

Tree view error

Please check the inspect view, my code is not rendered properly. *ngFor is still there and I am able to see interpolation symbol in my output. Don't know why my custom directive is not working. Here is the console output for reference.

Tree view console output

  • you should use structural directives for manipulating DOM – Artyom Amiryan Nov 15 '18 at 13:56
  • 1
    By doing `this.elRef.nativeElement.innerHTML = "..."` you add content directly to the DOM outside of an angular context (ngZone). So none of the angular components or directives will work here. Components are more suited for what you are trying to accomplish. I recommend you to learn the difference between components and directives. Or maybe check out angular ui libraries to find how they implemented tree view components. – Lars-Kristian Johansen Nov 15 '18 at 14:05

0 Answers0