<a *ngIf="isEmpty()" class="btn btn-outline-primary btn-sm" (click)="openModal(modal)">
    JSON
</a>

<ng-template #modal>
    <div class="modal-header">
        <h4 class="modal-title pull-left">{{ attribute.label }}</h4>
        <button type="button" class="close pull-right" aria-label="Close" (click)="modalRef.hide()">
            <span aria-hidden="true">&times;</span>
        </button>
    </div>
    <div class="modal-body">
        <ngx-json-viewer [json]="value"></ngx-json-viewer>
    </div>
</ng-template>