With the following code

<form>
    <select class="attkOptions" *ngFor="let subString of Attack.currentText" placeholder="" onchange="dumpValue(value)">
        <option [value]="{'index':Attack.currentText.indexOf(subString)}">{{subString.text}}</option>
        <option *ngFor="let option of subString.options" [value]="{'index':Attack.currentText.indexOf(subString),'option':option}">
            {{option}}
        </option>
    </select>
</form>

and component

export class Patterns implements OnInit, OnDestroy, OnChanges {
 ...
    dumpValue(object) {
        console.log(object.index);
        
    }
 ...
}

I am getting the following error Uncaught ReferenceError: dumpValue is not defined at HTMLSelectElement.onchange (module:18:9). I am able to call functions in my class in other points of the code, so my deduction is that by using it within ngFor, I somehow leave the scope of my class (and in fact, calling the function elsewhere in code works as expected.

How can I specify the scope of function to be within my class?