<vn-watcher
    vn-id="watcher"
    data="$ctrl.worker.sip">
</vn-watcher>
<form name="form" ng-submit="$ctrl.onSubmit()" class="vn-w-md">
    <vn-card class="vn-pa-lg">
        <vn-vertical>
            <vn-horizontal>
                <vn-textfield
                    label="Extension" 
                    ng-model="$ctrl.worker.sip.extension">
                </vn-textfield>
            </vn-horizontal>
        </vn-vertical>
    </vn-card>
    <vn-button-bar>
        <vn-submit
            disabled="!watcher.dataChanged()"
            label="Save">
        </vn-submit>
        <vn-button
            class="cancel"
            label="Undo changes"
            disabled="!watcher.dataChanged()"
            ng-click="watcher.loadOriginalData()">
        </vn-button>
    </vn-button-bar>
</form>