<label (click)="expandCat()" [ng-class]="{active: data.active}"> {{data.name}}</label> <ul [ng-class]="{active: data.active}"> <li *ng-for="var method of data.methods; var idx = index" [ng-class]="{active: method.active}" (click)="activateMethod(idx)"> {{method.summary}} </li> </ul>