Angular 2: Can't bind to x since it isn't a known native property

Question

In Angular 2 component I have authbox.component.ts

import {Component} from 'angular2/core';
import {COMMON_DIRECTIVES} from 'angular2/common';
import {Credentials} from './credentials'
@Component({
    selector: 'authbox',
    template: `<div>
       <div class="login-panel" *NgIf="!IsLogged">
            <input type="text" *NgModel="credentials.name" />
            <input type="password" *NgModel="credentials.password" />
            <button type="button" (click)="signIn(credentials)">→| Sign In</button>
        </div>
        <div class="logged-panel" *NgIf="IsLogged">
            <span>{nickname}</span>&nbsp;&nbsp; <button type="button" (click)="signOut()">|→ Sign out</button>
        </div>
    </div>`,
    directives: [COMMON_DIRECTIVES]
})


export class AuthBoxComponent {

    private _isLogged: boolean;

    get IsLogged(): boolean {
        return this._isLogged
    }
    set IsLogged(value: boolean) {
        this._isLogged = value;
    }

    public credentials: Credentials;

}

In browser I got errors «Can't bind to 'NgModel' since it isn't a known native property » and «Can't bind to 'NgIf' since it isn't a known native property».

I'm using beta 8.

Answer 1

In general, the can't bind to xxx since it isn't a known native property error occurs when you have a typo in your HTML when trying to use an attribute directive, or when trying to setup a property binding.

Common examples are when you miss a * or a # or let or use in instead of of with the Angular built-in structural directives:

<div  ngIf="..."                 // should be *ngIf
<div  ngFor="..."                // should be *ngFor="..."
<div *ngFor="let item in items"  // should be "let item of items"
<div *ngFor="item of items"      // should be "let item of items"

A misspelling or wrong case will also generate the problem::

<div *ngFer="..."
<div *NgFor="..."

Another reason is if you specify a property that doesn't exist on the DOM element or component:

<div [prop1]="..."       // prop1 isn't a valid DOM property for a div
<my-comp [answr]="..."   // typo, should be [answer]

---

For typos with the built-in Angular directives, since the typo doesn't match any of the built-in directive selectors, Angular tries to setup a binding to a property of the DOM element (the div in the above examples) with the typo name. This fails because a div does not have a native ngIf or ngFer or prop1 DOM property.

--

For attributes (not properties) you need to use attribute binding, for example for height attribute of svg: <svg [attr.height]="myHeightProp">

Answer 2

try using [(ngModel)] rather than *NgModel and *ngIf instead of *NgIf

<span>{{nickname}}</span>&nbsp;&nbsp; <button type="button" (click)="signOut()">|→ Sign out</button>

export class AuthBoxComponent {
    nickname="guest";
    ...
}