JavaScript之DOM等级概述

        这两日对DOM等级的理解不是太通透，就进Mozilla官网去看了一下，然后进行了首次的对技术文档的翻译工作，虽然官网也有中文解释，但我想，自己翻译出来时，已经有了原汁原味的理解了吧，这边是做此次翻译的原因所在。----Johnny Zen 2017-11-17

DOM Levels[DOM 等级概述]

    @source:https://developer.mozilla.org
    @translator:Johnny Zen
    @school:XiHua University
    @contact:QQ:1125418540
    @translate-completed-date:2017-11-27
    @notice:如翻译有误或JavaScript方面的技术交流，欢迎指正与沟通~

The following are "abstracts" of the DOM specifications from the World Wide Web Consortium. All this and more can be found at the W3C DOM site: http://www.w3.org/DOM.

以下是来自万维网联盟的DOM规格说明的摘要。所有关于这个或更多的问题的信息都可以在W3C DOM站点( http://www.w3.org/DOM)上找到

The purpose of this document is to give an overview of the different DOM Levels and the support Mozilla offers for each of them. If you're looking for an introduction to the DOM, see the Gecko DOM Reference.

这个文档的提案是为了给不同DOM等级和Mozilla提供的每一个(DOM)支持一个(统一的)总览。如果你正在寻找DOM的介绍，请看
Gecko DOM Reference的参考文献。

DOM Level 1

The DOM Level 1 specification is separated into two parts: Core and HTML. Core Level 1 provides a low-level set of fundamental(基础的) interfaces that can represent any structured document, as well as defining extended interfaces for representing an XML document. HTML Level 1 provides additional, higher-level interfaces that are used with the fundamental interfaces defined in Core Level 1 to provide a more convenient view of an HTML document. Interfaces introduced in DOM1 include, among others, the Document, Node, Attr, Element, and Text interfaces. All interfaces contain attributes and/or methods that can be used to with XML and HTML documents.

Level of support: Excellent. See our bugs in the Core and HTML specifications.

DOM 1 规约分为两部分：DOM1 Core和DOM1 HTML。DOM1 Core 提供了基础的能够代表任何结构化文档的接口的集合，也为XML文档定义了可扩展的接口。DOM1 HTML 提供了可添加的，更高级别的为了提供一种更方便的HTML文档的视图而能够与在 DOM1 Core中所已定义的基础接口一起使用的接口。

在DOM1 中所包含的已被引入的接口中，其中包括：Document、Node、Attr、Element和Text接口。
所有接口包含了的这些属性或者方法，能够使用HTML和XML文档所使用。

支持等级：最优。查看bugs:Core和DOM HTML

DOM Level 2

The DOM Level 2 specification contains six different specifications: The DOM2 Core, Views, Events, Style, Traversal and Range, and the DOM2 HTML. Most of the DOM Level 2 is supported in Mozilla.

DOM 2 规约包含了：DOM2 Core、视图(DOM View)、事件(DOM Event)、样式(DOM Style)、Traversal[不太理解，英文原意为：横断(物)](DOM Traversal)、Range[不太理解，英文原意：范围、类别、排列等]和 DOM2 HTML六大不同的模块。在Mozilla中，DOM2的大部分都被支持。

1. The DOM2 Core extends the functionality of the DOM1 Core. It also contains specialized interfaces dedicated to XML. Examples of methods introduced in the DOM2 Core include the famous getElementById, and many namespace-related methods.

Level of support: Very good. See our bugs in the Core specification.

1. DOM2 Core 延续了DOM1 Core的功能.它也包含了特化的专用于XML的接口.被引入的在DOM2 Core的方法范例包含了著名的getElementById和许多与命名空间相关的方法。

支持等级：非常好。查看bugs:Core

2.The DOM2 Views allows programs and scripts to dynamically access and update the content of a representation of a document. The introduced interfaces are AbstractView and DocumentView.

Level of support: Perfect.

DOM2 视图(DOM Views)，允许程序和脚本动态地访问和更新文档呈现的内容。这些被引入的接口属于抽象视图(AbstractView)和文档视图(DocumentView)。

支持等级：完美。

3.The DOM2 Events gives a generic event system to programs and scripts. It introduces the concepts of event flow, capture, bubbling, and cancellation. Famous methods here include addEventListener and handleEvent. Several interfaces make your life easier when dealing with events: EventTarget, EventListener, Event, DocumentEvent, MouseEvent, MutationEvent, etc. However, it does not include an interface for the keyboard events, which will be dealt with in later versions of the DOM.

Level of support: Very good. See our bugs in the Events specification.

DOM 2 事件(DOM2 Events)，为程序和脚本提供了一个泛化的事件系统.它引入了事件流。捕获、冒泡和阻止事件(或 译为：取消事件)的概念。著名的方法包括addEventListener和handleEvent.当你处理事件的时候，专有的(Several)接口使你的生活更简单：EventTarget（事件目标）、EventListener（事件监听器）、Event（事件）、DocumentEvent（文档事件）、鼠标事件（MouseEvent）、变化事件（MutationEvent）等。然而，它不包含键盘事件的接口，这会在DOM的后续版本中被处理。

支持等级：非常好。查看在Events 规约中的bugs： DOM Events

4.The DOM2 CSS, or DOM2 Style, allows programs and scripts to dynamically access and update the content of style sheets. It has interfaces for Style Sheets, Cascading Style Sheets, CSSRule, CSSStyleDeclaration, the famous getComputedStyle (supported in Mozilla), the many many CSS2Properties, and all the media rules you can imagine.
Level of support: Good. See our bugs in the Style specification.

DOM2 CSS(或 DOM2样式，DOM2 Style)，允许程序和脚本动态地访问和更新样式层叠表中的内容.它拥有为样式表、层叠样式表、CSS规则、CSS样式声明的接口，例如：有名的getComputedStyle（Mozilla中支持），许多许多的CSS2属性和所有的你能想象的多媒体规则的接口。

支持等级：好。查看 Style 规约的bugs：Style

5.The DOM2 Traversal and Range allow programs and scripts to dynamically traverse and identify a range of content in a document. The DOM2 Traversal provides interfaces like NodeIterator and TreeWalker to easily traverse the content of a document. The DOM2 Range allows the creation, insertion, modification, and deletion of a range of content in a Document, DocumentFragment, or Attr. It can be characterized as selecting all of the content between a pair of boundary-points.

Level of support: Good for Range; for Traversal, the TreeWalker is supported, and NodeIterator support was implemented in Firefox 3.5.

DOM2 Traversal and Range 允许程序和脚本动态地横越和识别在同一个document文档中内容的范围。为了简化衡越document文档的内容，DOM2 Traversal提供了像NodeIterator 和NodeIterator的接口。DOM2 范围(DOM 2 Range),允许创建、插入、修改和删除同一个Document、DocumentFragment或者 Attr类型节点中的内容。他能具有选择在一对边界点之间内容的所有节点。

支持等级：Range：好；Traversal，TreeWalker：已被支持，NodeIterator：已在FireFox 3.5中被实现。

6.The DOM2 HTML allows programs and scripts to dynamically access and update the content and structure of HTML documents. It extends the interfaces defined in the DOM1 HTML, using the DOM2 Core possibilities. It introduces the contentDocument property, a useful way to access the document contained in a frame.

Level of support: Good. See our bugs in the HTML specification.

DOM2 HTML,允许程序和脚本动态地访问和更新结构化的HTML文档的内容。它继承了在 DOM1 HTML中的结构，使用DOM2的可能性。它引进了contentDocument属性，一种有效的方式去访问包含在frame中的文档。

支持等级：好。查看DOM HTML的bugs：DOM HTML

DOM Level 3

The DOM Level 3 specification contains five different specifications: The DOM3 Core, Load and Save, Validation, Events, and XPath.

DOM3 规约包含了5大不同的模块：DOM3 Core、DOM3 Load、DOM3 Save、DOM3 Validation、DOM3 Events 和 DOM3 XPath。

1.The DOM3 Core will extend the functionality of the DOM1 and DOM2 Core specs. New methods and properties include adoptNode() and textContent, to name a couple.

Level of support: Only a few properties and methods are supported, like baseURI. If you want to help with the code, please see bug 159167.

DOM3 核心(The DOM3 Core)，继承了DOM1和DOM2 核心(Core) 的规约。新的方法和属性包括但不限于：adoptNode() 和 textContent等。

支持等级：只有一个新的属性和方法被支持，例如：baseURI。如果你想获取这段代码的帮助，请查看bug：159167.

2.The DOM3 Load and Save allows programs and scripts to dynamically load the content of an XML document into a DOM document, and serialize a DOM document into an XML document.

Level of support: None (bugs). Mozilla supports non-standard DOMParser and XMLSerializer objects instead.

DOM3 文档加载和保存(DOM3 Load and Save)，允许程序和脚本动态地加载XML文档的内容到DOM文档中，序列化DOM文档到XML文档中。

支持等级：无(bugs)。Mozilla支持非标准规约的 DOMParser 和 XMLSerializer 对象作为替代。

3.The DOM3 Validation allows programs and scripts to dynamically update the content and the structure of documents while ensuring that the document remains valid, or to ensure that the document becomes valid.

Level of support: None.

DOM3 Validation(DOM 3有效性验证),当能够确保文档保持有效的时候，才可允许程序和脚本动态地更新内容和结构化文档。

支持等级：无。

4.
The DOM3 Events is the extension of the DOM2 Events specification. This specification mainly focuses on keyboard events and how to handle them.

Level of support: Parts.

DOM3 Events 是 基于DOM2 Events规约的扩展。此版本规约主要聚焦于键盘事件和如何处理(操作)它们。

支持等级：部分支持。

5.The DOM3 XPath provides simple functionalities to access a DOM tree using XPath 1.0.

Level of support: Parts. See The DOM3 XPath

DOM3 XPath 提供了简单的功能用于访问使用XPath 1.0版本的DOM树

支持等级： 部分支持。查看：DOM3 XPath

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IMPORTANT LINKS(本文涉及的重要链接集合)

• https://developer.mozilla.org/fr/docs/DOM_Levels
• DOM
• World Wide Web Consortium
• http://www.w3.org/DOM
• Gecko DOM Reference
• DOM Core
• DOM HTML
• DOM Views
• DOM Events
• DOM Style
• DOM2 Traversal and Range
• DOM3 Load and Save
• DOM3 XPath