将下拉列表的值传递给angular js

Question

我希望在 ng-model 中设置下拉列表的值和文本框的值，以将其传递给 angular js 。

控制台显示 null 作为我的下拉菜单的值。

我尝试过的事情：

<form id="uploadForm">
   <div id="republishSingle" class="panel-collapse collapse in desc vertical" style="text-align: left">
      <div class="horizontal">
         <div class="dropdown">
            <button type="button" class="btn btn-light dropdown-toggle" data-toggle="dropdown" id="selectSource1" aria-haspopup="true" aria-expanded="true" ng-model="republishSource">
            Source system
            </button>
            <div class="dropdown-menu" aria-labelledby="dropdownMenu1">
               <h5 class="dropdown-header">Source system</h5>
               <a class="dropdown-item" href="#" data-value="s1">S1</a>
               <a class="dropdown-item" href="#" data-value="s2">S2</a>
            </div>
         </div>
         <div class="col-5">
            <input class="form-control disableButton" id="policy" type="text" placeholder="Policy" ng-model="republishInput"/>
         </div>
         <div class="form-group mb-3">
            <div class="form-group" aria-label="file upload">
               <input id="republish" type="submit" class="btn btn-success"
                  ng-click="doRepublish(republishSource,republishInput)" value="Republish"/>
            </div>
         </div>
      </div>
   </div>
</form>