scratch.html

<load-component
        [loadingMessage]="'Loading customers'"
        [errorMessage]="'Problem during loading customer list'"
        [emptyMessage]="'There are no customer'">
    <customer-list (onload)="loaded()"
                    (onerror)="error()"
                    (onempty)="empty()"></customer-list>
</load-component>



<div>
    <div *ngIf="loading">{{laodingMessage}} or spinner</div>
    <div *ngIf="loaded && !empty()">
        <content></content>
    </div>

    <div *ngIf="loaded && empty()">
        {{emptyMessage}}
    </div>

    <div *ngIf="loadingError">
        {{errorMessage}}
    </div>
</div>