angularjs实现table增加tr的方法

<tr ng-repeat="rule in formData.ruleList track by $index">

.directive(
   'kbnTableRow',
   function($compile) {
    return {
    restrict : 'A',
    link : function(scope, element) {
    element.after('<tr>');
   function expressDescHtml() {
   var detailHtml = '<td></td><td colspan="5">'
   + '<div ng-show="rule.type!==1">'
    + '<div class="col-xs-9 row">'
 + ' <input type="text" class="form-control" ng-model="rule.exprDesc"readonly ">'
+ '</div>'
+'</div>' + '</td>';
return detailHtml;
    }
  },
 templateUrl : 'libs/kbnTable/table_row/rule.html'
      };
     });

<td class="form-control-static">
 <div class="form-control-static">{{$index+1}}</div>
</td>
<td>
 <div class="form-control-static" ng-show="rule.type===1"
  style="text-align: -webkit-left;">&nbsp&nbsp&nbsp{{rule.rightVar.desc}}</div>
 <div ng-show="rule.type!==1">
  <div class="col-xs-9 row">
   <input type="text" class="form-control" ng-model="rule.rightVar.desc"
    readonly title="{{rule.rightVar.desc}}">
  </div>
  <div class="col-xs-3 ">
   <button class="btn btn-warning"
    ng-click="showRightVar(rule,'rightVar')">设置</button>
  </div>
 </div>
</td>
<td class="form-control-static" ng-show="formData.execType == 't02'">
 <div class="form-control-static" style="padding-top: 0;">
  <input type="text" class="form-control" ng-model="rule.score"
   title="{{rule.score}}" />
 </div>
</td>
<td class="td-button" style="padding-left: 0; padding-right: 1px;">
 <button class="btn btn-danger" ng-click="del(rule)">删除</button> <input
 type="hidden" ng-model="rule.enable" />
</td>
<td class="td-button" style="padding: 8px 0;">
 <button class="btn btn-danger" ng-click="disabledRule(rule, $event)">
  <span ng-if="rule.enable == 0">启用</span> <span
   ng-if="rule.enable == 1">禁用</span>
 </button>
</td>

<div class="row">
   <div class="col-xs-12 row">
    <h4 class="col-xs-12">
     <b>表达式设置</b>
    </h4>
   </div>
   <div class="col-xs-12">
    <div class="row">
     <div class="col-xs-10">
      <table class="table text-center">
       <tr>
        <th ng-click="toggleAll()">
          <i class="fa discover-table-open-icon"
          ng-class="{ 'fa-caret-down': formData.on, 'fa-caret-right': !formData.on }"> 
          </i>
        </th>
        <th width="45px">序号</th>
        <th>左变量</th>
        <th>操作符</th>
        <th>右变量</th>
        <th width="75px" ng-show="formData.execType == 't02'">分值</th>
        <th colspan="2">操作</th>
        <th></th>
       </tr>
       <tbody>
        <tr ng-repeat="rule in formData.ruleList track by $index"
         kbn-table-row class="discover-table-row"></tr>
       </tbody>
      </table>
     </div>
     <div class="col-xs-1">
      <button class="btn btn-info" ng-click="addRule()">新增</button>
     </div>
    </div>
   </div>