屬性變更事件

使用 notify:true 的屬性也會觸發事件

<link rel="import" href="../bower_components/paper-input/paper-input.html">
<dom-module id="property-change-event">
  <template>
    <style></style>
    <paper-input id="input" label="type here to fire value change event" on-value-changed='changeFired'></paper-input>
  </template>
</dom-module>
<script>
  Polymer({
    is:'property-change-event',
    changeFired:function(e){
      if(e.detail.value!="")
        alert("new value is: "+e.detail.value);
    }
  })
</script>