dart angular2 - null error when rendering an object in template

Question

I'd like to write in my template something like :

 <span>{{myObject.myField}}</span>

However myObject is initialized in my ngOnInit, and my object seems to still be null when the page is rendered because I have the following error

NullError: method not found: 'myField' on null

If I only put in my template

 <span>{{myObject}}</span>

I can see the value of myObject.

Is there a way to initialize my object before OnInit ? Is there another way to display my data ?

Thanks for your help.

Günter Zöchbauer · Accepted Answer · 2016-09-29 12:57:29Z

2

You can use the safe-navigation operator

<span>{{myObject?.myField}}</span>

to prevent errors while the model is not yet fully initialized

Alternatively you can wrap the elements with *ngIf to prevent them being rendered when the model is not yet initialized

<span *ngIf="myObject != null">{{myObject.myField}}</span>

This way you can cover bigger blocks or the whole template with a single *ngIf instead of adding ? everywhere.

answered Sep 29, 2016 at 12:57

Günter Zöchbauer

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3 Comments

matth3o Over a year ago

<span>{{myObject?.myField}}</span> works perfectly. Thanks!

Adamovskiy Over a year ago

In our project in same cases we usually add additional *ngIf="myObject == null" with some kind of spinner or loading lable as content, to indicate that component is not initialized yet. This approach can be easily converted to some custom guard control.

Günter Zöchbauer Over a year ago

@StefanSvrkota Sure. Can you please delete yours. Dart is a nice language to build browser applications (and also server, and mobile, apps). Definitely worth a closer look ;-)

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