ng-repeat with Array of Strings

ng-repeat does not like primitives. To workaround this, use track by $index in ng-repeat, and array[$index] in the ng-model.

<div class="form-group form-group-sm" ng-repeat="tag in tags track by $index">
    <label class="control-label col-xs-3">Tag:</label>
    <div class="col-xs-6">
        <input class="form-control input-sm" ng-model="tags[$index]" />
    </div>
    <div class="col-xs-3">
        <button class="btn btn-sm" ng-click="tags.splice(tags.indexOf(tag),1)">Delete Tag</button>
    </div>
</div>