<mat-card *ngFor="let msg of notifications$.messages">
    <mat-card-content>
        <span class="text">{{msg.text}}</span>
        <span class="btn" *ngIf="msg.btn">
            <a class="action-button" (click)="notifications$.doAction(msg)">{{msg.btn}}</a>
        </span>
    </mat-card-content>
</mat-card>