jqxTree, ERROR TypeError: Cannot read property 'length' of null

[barbozaParticipant]

Hi all!

I’m a newbie to this framework and to Angular as well.

I created a tree

<jqxTree #treeReference
         [width]="200" [height]="'100%'" [source]="projects | async">
</jqxTree>

with component code:

import {AfterViewInit, Component, ViewChild, ViewEncapsulation} from "@angular/core";
import {jqxTreeComponent} from "jqwidgets-scripts/jqwidgets-ts/angular_jqxtree";
import "rxjs/add/observable/of";
import * as  Rx from "@reactivex/rxjs";

@Component({
  selector: "app-root",
  templateUrl: "./desktop.component.html",
  styleUrls: ["./desktop.component.css"],
  encapsulation: ViewEncapsulation.None
})
export class DesktopComponent implements AfterViewInit {
  height: number | string = 500;
  projects = this.projects = Rx.Observable
    .fromPromise(
      Promise.resolve([{id: 1, label: "TEST"}])).map((values: any[]) => {
      return values.map((p: any) => {
        return {id: p.id, label: p.name, parentid: p.parentId};
      });
    });

  @ViewChild("treeReference")
  tree: jqxTreeComponent;

}

I got an error:

ERROR TypeError: Cannot read property ‘length’ of null
at jqxTreeComponent.arraysEqual (webpack-internal:///../../../../jqwidgets-scripts/jqwidgets-ts/angular_jqxtree.ts:73)

After spending some time in debug I came up to the conclusion, that there is a mistake in arraysEquals method.
If I change the method to:

arraysEqual(attrValue: any, hostValue: any): boolean {
    // check that previous/currentVlaue is undefined or null
    if ((attrValue && !hostValue) || (!attrValue && hostValue)) {
      return false;
    }
    if (attrValue.length != hostValue.length) {
      return false;
    }
    for (let i = 0; i < attrValue.length; i++) {
      if (attrValue[i] !== hostValue[i]) {
        return false;
      }
    }
    return true;
  }

it begins to work.

[Ivo ZhulevParticipant]

Hi barboza,

Thanks for the report. This will be considered and if approved, added in the next release!

Best Regards,
Ivo

jQWidgets Team
http://www.jqwidgets.com/

[Author]

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