@accede-web/overlay 中文文档教程

Question

AcceDe Web - overlay

没有依赖项的 WAI-ARIA 叠加插件。

这个插件是用 ES2015 编写的，可以在 /lib 文件夹中以未编译的形式使用，也可以在 /dist 文件夹中为 ES5 编译。 如果您的项目将 babel 与 Webpack 或 Rollup 一起使用，您应该更改排除项以便编译此插件，或者强制 Webpack 或 Rollup 使用 package.json 的 main 条目获取编译版本 文件而不是 module 条目。

// .babelrc file or configuration within webpack or rollup
{
  "plugins": [...],
  "exclude": "node_modules/!(@accede-web)/**",
}

Installation

$ npm install @accede-web/overlay

Methods

Name	Description
show()	Switch the aria-hidden attribute to false and disable the rest of the document (if the modal parameter is not set to false)
close( returnValue )	Switch the aria-hidden attribute to true and enable the rest of the document if needed. Dispatch close event on the overlay. Also available on the root element of the overlay. The returnValue property can be sent invoking this method
addEventListener(eventName, callback)	Shortcut to listen to the close or cancel events
removeEventListener(eventName, callback)	Shortcut to stop listening to the close or cancel events

Properties

Name	Description
el	The HTML root element of the overlay
returnValue	Also available on the HTML root element. Allows you to pass data between the overlay and the document

Static properties

与实例的属性相反，静态属性在构造函数中可用。

Name	Description
stack	Pending overlay stack. Array of all the overlays currently open

Events

Name	Description
close	Triggered when the method .close() is called
cancel	Triggered when the parameter closeOnCancel is true and an escape key keydown or a click outside the overlay is happening. Can be prevented with event.preventDefault(). Triggers a close event when not prevented

Inserting an element in an overlay

HTML

<!-- content to be insterted in an overlay -->
<section class="overlay">
  <header class="layer-header">
    <button class="button-close">
      <span>Close</span>
    </button>
    <h2 class="layer-title">Modal window</h2>
  </header>
  <div class="layer-content">
    <p>…</p>
  </div>
</section>

JavaScript

// the content property can be an HTMLElement
var overlay = new Overlay({
  content: document.querySelector( '.overlay' )
});

// … or an HTML string
var overlay = new Overlay({
  content: '<div><p>Hello</p></div>'
});

overlay.addEventListener( 'close', e => {
  // the value returned by the overlay
  console.log( e.target.returnValue );
});

// Display the overlay
overlay.show();

// Close the overlay and pass the return value
overlay.close( 'returnValueData' );

Parameters

Mandatory parameters

Name	Type	Description
content	HTMLElement or String	Content to insert in the overlay.

Optional parameters

Name	Type	Description
className	String	HTML classes to add to the overlay (space separated)
closeOnCancel	Boolean	Allow the Escape key or a click outside the overlay to close it. Defaults to true
closeSelector	String	CSS selector to match any element that will close the overlay when clicked
modal	Boolean	Should the overlay be modal (disable anything but the overlay on the page). Defaults to true
opener	HTMLElement	HTML element that will receive the focus once the overlay is closed. Defaults to the current active element
tagName	String	Change the tag name of the overlay. Defaults to <div>
role	String	Specify the role attribute of the overlay. Can be dialog or alertdialog
titleSelector	String	Mandatory when using a role attribute and no label property, a CSS selector matching the title the overlay should have. Defaults to [data-label]
label	String	Mandatory when using a role attribute and there's no title displayed in the overlay to specify the title of the overlay

Passing the formated overlay

在这种情况下，叠加层是传递给脚本的有效且可访问的 HTML 结构。 该脚本用于处理事件和禁用文档。

HTML

<!-- valid overlay structure example -->
<div role="alertdialog" class="layer" aria-hidden="true" aria-labelledby="layerTitle" aria-describedby="layerDesc">
  <section class="layer">
    <header class="layer-header">
      <button class="button-close">
        <span>Close</span>
      </button>
      <h2 class="layer-title" id="layerTitle">Warning</h2>
    </header>
    <div class="layer-content">
      <p id="layerDesc">Your confirmation number is required before continuing.</p>
    </div>
  </section>
</div>

JavaScript

var overlay = new Overlay( document.querySelector( '.layer' ), {
  closeOnCancel: false,
  opener: document.querySelector( 'button' ),
  closeSelector, '.button-close'
  modal: false
});

// Display the overlay
overlay.show();

// Close the overlay
overlay.close();

Optional parameters

Name	Type	Description
closeOnCancel	Boolean	Allow the Escape key or a click outside the overlay to close it. Defaults to true
closeSelector	String	CSS selector to match any element that will close the overlay when clicked
modal	Boolean	Should the overlay be modal (disable anything but the overlay on the page). Defaults to true
opener	HTMLElement	HTML element that will receive the focus once the overlay is closed. Defaults to the current active element

Keyboard Interaction

• Tab: Moves focus to the next tabbable element inside the overlay.
• Shift + Tab: Moves focus to the previous tabbable element inside the overlay.
• Escape: Closes the overlay.

Polyfill

为了调度 close 和 cancel 事件，脚本使用了 CustomEvent 构造函数。 当需要 Internet Explorer 的支持时，CustomEvent 的 polyfill 是必需的。 您可以在 MDN 网站 上找到一个。

Compatibilty

此插件针对以下浏览器进行了测试：

• Internet Explorer 11 and higher
• Microsoft Edge
• Chrome
• Firefox
• Safari

Testing

安装项目依赖项：

  $ npm install

运行自动化测试用例：

  $ npm test

Development

要在本地测试，您可以运行：

  $ npm run server

然后转到 http: //本地主机:3000/测试