- 创建自定义事件（Creating custom events）
- 增加自定义数据（Adding custom data - CustomEvent()）
- 老式的方式（old-fashioned way）
- 事件冒泡（event bubbling）
- 动态创建和触发事件（creating and dispatching events dynamically）
- 触发内置事件 (Triggering built-in events)
- vue项目热力图实战（为iView的Table组件的TableCell DOM元素创建事件并触发，动态增删class实现热力图过滤）
创建自定义事件（Creating custom events）
var event = new Event('build'); // Listen for the event. elem.addEventListener('build', function (e) { /* ... */ }, false); // Dispatch the event. elem.dispatchEvent(event);
IE是朵奇葩，需要参考 老式的方式 创建事件。
增加自定义数据（Adding custom data - CustomEvent()）
CustomEvent()可以通过detail属性为事件增加数据。
var event = new CustomEvent('build', { detail: "foo" }); elem.addEventListener('build', function (e) { console.log(e.detail) });
老式的方式（old-fashioned way）
// Create the event. var event = document.createEvent('Event'); // Define that the event name is 'build'. event.initEvent('build', true, true); // Listen for the event. elem.addEventListener('build', function (e) { // e.target matches elem }, false); // target can be any Element or other EventTarget. elem.dispatchEvent(event);
事件冒泡（event bubbling）
从一个子元素触发事件，祖先元素去捕获它，可以选择性传入数据。
事先创建好自定义事件。
<form> <textarea></textarea> </form>
const form = document.querySelector('form'); const textarea = document.querySelector('textarea'); // Create a new event, allow bubbling, and provide any data you want to pass to the "detail" property const eventAwesome = new CustomEvent('awesome', { bubbles: true, detail: { text: () => textarea.value } }); // The form element listens for the custom "awesome" event and then consoles the output of the passed text() method form.addEventListener('awesome', e => console.log(e.detail.text())); // As the user types, the textarea inside the form dispatches/triggers the event to fire, and uses itself as the starting point textarea.addEventListener('input', e => e.target.dispatchEvent(eventAwesome));
动态创建和触发事件（creating and dispatching events dynamically）
触发时才创建自定义事件。
<form> <textarea></textarea> </form>
const form = document.querySelector('form'); const textarea = document.querySelector('textarea'); form.addEventListener('awesome', e => console.log(e.detail.text())); textarea.addEventListener('input', function() { // Create and dispatch/trigger an event on the fly // Note: Optionally, we've also leveraged the "function expression" (instead of the "arrow function expression") so "this" will represent the element this.dispatchEvent(new CustomEvent('awesome', { bubbles: true, detail: { text: () => textarea.value } })) });
触发内置事件
function simulateClick() { var event = new MouseEvent('click', { view: window, bubbles: true, cancelable: true }); var cb = document.getElementById('checkbox'); var cancelled = !cb.dispatchEvent(event); if (cancelled) { // A handler called preventDefault. alert("cancelled"); } else { // None of the handlers called preventDefault. alert("not cancelled"); } }
vue项目热力图实战
为iView的Table组件的TableCell DOM元素创建事件并触发，动态增删class实现热力图过滤。
methods: { // 表格订阅事件 tdSubscribe() { this.$nextTick(() => { // 获取所有class以blue-alpha开头的table cell this.tableCells = document.querySelectorAll('td[class^="blue-alpha"]'); this.tableCells.forEach((cell) => { cell.addEventListener('toggleCell', (e) => { if (e.detail) { e.target.classList.add('hidden-cell'); } else { e.target.classList.remove('hidden-cell'); } }); }); }); }, // 表格触发事件 tdTrigger(range) { this.tableCells.forEach((cell) => { const cellValue = parseInt(cell.innerText); const rangeMin = range[0]; const rangeMax = range[1]; const hiddenCtrl = cellValue < rangeMin || cellValue > rangeMax; // 新建自定义事件 toggleCell “toggle渲染单元格”blue-alpha-8-*类名 const toggleEvent = new CustomEvent('toggleCell', { detail: hiddenCtrl }); cell.dispatchEvent(toggleEvent); }); }, },
