TypeError：无法读取null的属性'$ data'

Question

尝试使用ng-repeat将数据填充到可编辑的表格数据时，我遇到了这个问题。

以下是我更新的代码：

 <table>
 <tr style="white-space: nowrap">
   <td ng-repeat="assignment in vm.assignments" class="text-center">
                 <span>
                     {{ assignment.name }}
                     &nbsp;
                 </span>
                  <form editable-form name="{{assignment.name}}" ng-show="{{assignment.name}}.$visible">
                         <button type="submit" ng-disabled="{{assignment.name}}.$waiting">
                             save
                         </button>
                         <button type="button" ng-disabled="{{assignment.name}}.$waiting" 
                             ng-click="$eval(assignment.name).$cancel()">
                             cancel
                         </button>
                     </form>
                     <a ng-show="!{{assignment.name}}.$visible" ng-click="$eval(assignment.name).$show()">
                         edit
                     </a>
             </td>
</tr>
<tr ng-repeat="assignment in vm.assignments">
    <td ng-repeat="grade in assignment.grades" class="text-center">
        <span editable-text="grade.score" e-name="{{ grade.aname }}" e-form="{{grade.aname}}">
            {{ grade.score || '-' }}
        </span>
    </td>
</tr>
 </table>

JS

  Assignment.GetAssignmentsByClassId(classId).then(function (data) {
            vm.assignments = data;
            vm.givenAssignments = _.filter(vm.assignments, { 'given': true });
  });

呈现HTML

   <span editable-text="grade.score" e-name="research" e-form="research" class="ng-scope ng-binding editable">
            90
       </span>