我需要在自定义 Polymer 2 元素中包含一个 vaadin-grid 并且需要处理行选择事件,但我似乎无法让它工作。我已经设法从提供的各种入门模板和演示中拼凑起来,基本的点击事件处理程序可以工作,但我不知道如何处理行选择。我实际上正在使用 vaadin-grid 的 v3.0.0-beta1,因为我无法让 v2 工作,但我认为这不是我的问题。
当您将它们包含在自己的自定义元素中时,有谁知道如何处理 vaadin 组件中的事件?
谢谢。
<link rel="import" href="bower_components/polymer/polymer-element.html">
<link rel="import" href="bower_components/iron-ajax/iron-ajax.html">
<link rel="import" href="bower_components/vaadin-grid/vaadin-grid.html">
<dom-module id="my-element">
<template>
<style>
:host {
display: block;
}
</style>
<iron-ajax auto url="https://demo.vaadin.com/demo-data/1.0/people?count=200" handle-as="json" last-response="{{users}}"></iron-ajax>
<vaadin-grid aria-label="My Test Grid" items="[[users.result]]" id="grid">
<vaadin-grid-column width="50px" flex-grow="0">
<template class="header">#</template>
<template>[[index]]</template>
</vaadin-grid-column>
<vaadin-grid-column>
<template class="header">First Name</template>
<template>[[item.firstName]]</template>
</vaadin-grid-column>
<vaadin-grid-column>
<template class="header">Last Name</template>
<template>[[item.lastName]]</template>
</vaadin-grid-column>
<vaadin-grid-column width="150px">
<template class="header">Address</template>
<template>
<p style="white-space: normal">[[item.address.street]], [[item.address.city]]</p>
</template>
</vaadin-grid-column>
</vaadin-grid>
</template>
<script>
class MyElement extends Polymer.Element {
static get is() { return 'my-element'; }
ready() {
super.ready();
this.$.grid.addEventListener('click', e => {
this._handleClick(e)
});
// I added this listener code from here: https://vaadin.com/elements/-/element/vaadin-grid#demos
// but it does nothing. I've also tried adding it to this, this.$, this.$.grid without success.
// Should this event listener be added here, or if not, where exactly? The docs are very unclear.
addEventListener('WebComponentsReady', function() {
Polymer({
is: 'my-element',
properties: {
activeItem: {
observer: '_activeItemChanged'
}
},
_activeItemChanged: function(item) {
this.$.grid.selectedItems = item ? [item] : [];
console.info('row clicked');
}
});
// this works and outputs info like this: "vaadin-grid-cell-content-17 was clicked."
_handleClick(e) {
console.info(e.target.id + ' was clicked.');
}
}
window.customElements.define(MyElement.is, MyElement);
</script>
</dom-module>
我认为我在 addEventListener 中的代码是 Polymer 1.x 语法,但我不确定如何使用 Polymer 2.x 实现相同的结果。