Uib 下拉菜单为空 Name/Lable 未打开

Uib Dropdown With Empty Name/Lable not Opening

在我的应用程序中可以有多个空名称的下拉列表 (这意味着他们没有为他们设置值)。

但是当 uib-dropdown 为空时不会打开 name/lable。

我能做什么?

 <div>
    <span uib-dropdown on-toggle="toggled(open)">
      <a href id="simple-dropdown" uib-dropdown-toggle>
      </a>
      <ul class="dropdown-menu" uib-dropdown-menu aria-labelledby="simple-dropdown">
        <li ng-repeat="choice in items">
          <a href>{{choice}}</a>
        </li>
      </ul>
    </span>
 </div>

Plunker

只需添加 &nbsp 即可

<div>
    <span uib-dropdown on-toggle="toggled(open)">
      <a href id="simple-dropdown" uib-dropdown-toggle>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
      </a>
      <ul class="dropdown-menu" uib-dropdown-menu aria-labelledby="simple-dropdown">
        <li ng-repeat="choice in items">
          <a href>{{choice}}</a>
        </li>
      </ul>
    </span>
 </div>

plunker