Polymer template dom-repeat with Firefox i get ReferenceError: event is not defined, IE ok, chrome ok

Polymer template dom-repeat with Firefox i get ReferenceError: event is not defined, IE ok, chrome ok

以下 Polymer 代码适用于 IE11 和 chrome V50

<template is="dom-repeat" items="[[buddys]]" as="partner">
 <paper-card style="width:100%;">
   <div class="card-content">
     [[partner.name]]

     <paper-icon-button 
            id="more-info"
            icon="more-horiz"
            on-click="_spielerDialog"
            data-index$="[[partner.__firebaseKey__]]"
            style="float:right;">
     </paper-icon-button>

  </div>
 </paper-card>
</template>

_spielerDialog: function() {
 var iconButton = Polymer.dom(event).localTarget;
 var key = iconButton.getAttribute("data-index");
 this.spielerid = key;
 this.$.spielerDialog.open()
 },

使用 Firefox V 45.0.2 单击图标按钮后出现 ReferenceError: 事件未定义

抱歉,事件 的功能是解决方案

_spielerDialog: function(**event**) {