hasError should not active when pristine.

[vellengs]

`<div *ngIf="formProperty.visible" [class.has-error]="!control.valid" [class.has-success]="control.valid"> <sf-widget-chooser (widgetInstanciated)="onWidgetInstanciated($event)" [widgetInfo]="formProperty.schema.widget"> <sf-form-element-action *ngFor="let button of buttons" [button]="button" [formProperty]="formProperty">

`

https://github.com/makinacorpus/angular2-schema-form/blob/master/src/formelement.component.ts