I'm building a dynamic form following the cookbook documentation
In addition, I have a directive with the selector input[type=signature].
If I use this in dynamic-form-question.component.ts: 
<input *ngSwitchCase="'signature'"
            [id]="question.attribs.name" 
            [formControlName]="question.attribs.name" 
            type="signature" 
            class="signature" />
my directive matches.
However, if I use
<input *ngSwitchDefault
            class="form-control"
            [formControlName]="question.attribs.name"
            [id]="question.attribs.name"
            [ngClass]="question.attribs.class"
            [placeholder]="question.attribs.placeholder"
            [type]="question.attribs.type" />
where the type.attribute is bound, it's no dice.
likewise I tried the selector input.signature and input.signature, input[type=signature], but they also don't work if the class or type attributes are bound.
Is this not supported, do I need to do something else to get this functionality?
 
     
     
    