如何在父lit-element组件中挂钩数据网格事件？

Question

我想对放置在数据网格行中的元素所引发的事件做出反应。Vaading data-grid防止事件冒泡到包含网格的父组件。在网格列中为每一行呈现按钮时，我无法捕获来自托管网格的组件的单击或任何其他事件。

来自https://vaadin.com/components/vaadin-grid/html-examples的示例依赖于附加在html文件中的js挂钩。我正在使用Lit-element，并试图在firstUpdated()回调中做同样的事情。问题是，显然在这一点上，表是不可用的。

<vaadin-grid id="test" .items=${this.data} theme="compact">
    <vaadin-grid-column width="40px" flex-grow="0">
        <template class="header">#</template>
        <template>
            <vaadin-button style="font-size:10px;" theme="icon" focus-target @click="${(e) => { console.log(e) }}">
                <iron-icon icon="icons:create"></iron-icon>
            </vaadin-button>
        </template>
    </vaadin-grid-column>
</vaadin-grid>

我希望有日志，但没有发生任何事情，因为网格组件阻止事件冒泡到我的组件。

尝试为vaadin-grid-column实现渲染器属性的代码：

import { LitElement, html, css } from 'lit-element'
import {render} from 'lit-html';

import '@vaadin/vaadin-grid/vaadin-grid.js'
import '@vaadin/vaadin-grid/vaadin-grid-filter-column.js'
import '@vaadin/vaadin-grid/vaadin-grid-sort-column.js';
import '@vaadin/vaadin-grid/vaadin-grid-filter.js';
import '@vaadin/vaadin-grid/vaadin-grid-sorter.js'

export default class MyClass extends LitElement {
    static get properties () {
        return {
            data: { 
                type: Array,
                hasChanged: () => true
            },

        }
    }

    get grid() {
        return this.shadowRoot.querySelector('vaadin-grid');
    }

    constructor () {
        super()
        this.data = []//is being assigned from super as a property to a custom element 
    }
    render () {
        return html`
            <vaadin-grid id="test" .items=${this.data}>
                <vaadin-grid-column .renderer=${this.columnRenderer} header="some header text"></vaadin-grid-column>
            </vaadin-grid>
        `
    }

    columnRenderer(root, column, rowData) {
        render(html`test string`, root);
    }
}
window.customElements.define('my-elem', MyClass)

Answer 1

在基于LitElement的组件中使用vaadin-grid时，应该使用renderers

下面是使用渲染器时代码的外观

import {LitElement, html} from 'lit-element';
// you need lit-html's render function
import {render} from 'lit-html';

class MyElement extends LitElement {
  // we'll just assume the data array is defined to keep the sample short
  render() {
    return html`
      <vaadin-grid id="test" .items=${this.data} theme="compact">
        <vaadin-grid-column width="40px" flex-grow="0" .renderer=${this.columnRenderer} .headerRenderer=${this.columnHeaderRenderer}></vaadin-grid-column>
      <vaadin-grid>
    `;
  }
  columnHeaderRenderer(root) {
    render(html`#`, root);
    // you could also just do this
    // root.textContent = '#'
    // or actually just use the column's header property would be easier tbh
  }
  columnRenderer(root, column, rowData) {
    render(
      html`
        <vaadin-button style="font-size: 10px;" theme="icon" focus-target @click="${(e) => { console.log(e) }}">
          <iron-icon icon="icons:create"></iron-icon>
        </vaadin-button>
      `, root);
  }
}

在这个由vaadin团队成员之一创建的Glitch中，您可以在LitElement中看到vaadin-grid的这些特性和更多特性