PrimeNG TreeTable Empty

Question

In an attempt to use PrimeNG in an Angular 4.1 project I am having some issues.

Here is the documentation I was following: https://www.primefaces.org/primeng/#/treetable

I'm testing the TreeTable feature but the output that is in the UI is empty. It displays the cells with no content and the have class="undefined".

app.component.html:

<p-treeTable *ngIf="treeNode" [value]="treeNode">
  <p-column field="id" header="ID"></p-column>
  <p-column field="label" header="Label"></p-column>
</p-treeTable>

app.module.ts:

import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';
import { CommonModule } from '@angular/common';
import { HttpModule } from '@angular/http';
import { BrowserAnimationsModule } from '@angular/platform-browser/animations';

import { TreeTableModule, SharedModule } from 'primeng/primeng';

import { AppComponent } from './app.component';
import { CustomerTypeService } from '../app-configure/service/app.customer.type.service';

@NgModule({
  declarations: [
    AppComponent
  ],
  imports: [
    CommonModule,
    BrowserModule,
    HttpModule,
    BrowserAnimationsModule,
    TreeTableModule,
    SharedModule
  ],
  providers: [CustomerTypeService],
  bootstrap: [AppComponent]
})
export class AppModule { }

app.component.ts:

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

import { CustomerTypeService } from '../app-configure/service/app.customer.type.service';

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css'],
  providers: []
})
export class AppComponent implements OnInit {
  treeNode: TreeNode[];

  constructor(private customerTypesService: CustomerTypeService) {}

  ngOnInit(): void {
    this.customerTypesService.getCustomerTypes()
        .then(treeNode => {
          this.treeNode = treeNode;
          console.log(this.treeNode);
        });
  }
}

Here is the JSON string that I'm getting back from the HTTP request: [{"id":1,"label":"Account","parentId":null,"parentLabel":null},{"id":2,"label":"Bank Account","parentId":1,"parentLabel":"Account"},{"id":3,"label":"Test","parentId":null,"parentLabel":null}]

app.customertype.service.ts:

import { Injectable } from '@angular/core';
import { Http } from '@angular/http';
import 'rxjs/add/operator/toPromise';

import {DefaultConfiguration} from '../../app/app.defaults';
import {CustomerType} from '../model/customer.type';
import {TreeNode} from 'primeng/primeng';

@Injectable()
export class CustomerTypeService {
    constructor(private http: Http) {}

    /**
     * Returns an array of all Customer Types.
     * @returns {Promise<CustomerType[]>}
     */
    getCustomerTypes(): Promise<TreeNode[]> {
        return this.http
            .get(`${DefaultConfiguration.BASE_API_URL}/CustomerTypes/`, DefaultConfiguration.getHeaders())
            .toPromise()
            .then(response => <TreeNode[]> response.json())
            .catch(DefaultConfiguration.handleError);
    }
}

Answer 1

Add *ngIf="treeNode" in

<p-treeTable [value]="treeNode" *ngIf="treeNode">...</p-treeTable>

The object TreeNode implement this interface

export interface TreeNode {
 label?: string;
 data?: any;
 icon?: any;
 expandedIcon?: any;
 collapsedIcon?: any;
 children?: TreeNode[];
 leaf?: boolean;
 expanded?: boolean;
 type?: string;
 parent?: TreeNode;
 partialSelected?: boolean;
 styleClass?: string;
 draggable?: boolean;
 droppable?: boolean;
 selectable?: boolean;
}

you web service is returning a array of element that not implements interface TreeNode, it does not have property id.

This array

[{"id":1,"label":"Account","parentId":null,"parentLabel":null},{"id":2,"label":"Bank Account","parentId":1,"parentLabel":"Account"},{"id":3,"label":"Test","parentId":null,"parentLabel":null}]

not is TreeNode[]