html5遵循的6个设计原则_html/css_WEB-ITnose
前面的话
实际上，html5并不是由w3c直接制定的，w3c的方向是xhtml2，而不是html5。当xhtml2脱离现实，无法付诸实践时，w3c工作组才将研究方向转向html5。为什么xhtml2从未落到实处？因为它违反了一条设计原理，这条设计原理就是著名的伯斯塔尔法则——发送时要保守；接收时要开放。而在html5设计过程中遵循了一系列原则，才使得html5得以快速推广。本文将介绍html5遵循的6个设计原则
原则一：避免不必要的复杂性
html4
<!DOCTYPE html PUBLIC "-//W3C/DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
html5
<!DOCTYPE html>
html4
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
html5
<meta charset="utf-8">
原则二：支持已有的内容
以下四段代码，在xhtml中只有第一段是正确的；而在html5中，所有的都是正确的
<img src="/static/imghw/default1.png" data-src="foo" class="lazy" alt="bar" /><p class="foo">Hello world</p> <img src="/static/imghw/default1.png" data-src="foo" class="lazy" alt="bar"><p class="foo">Hello world <img src="/static/imghw/default1.png" data-src="foo" class="lazy" ALT="bar" alt="html5遵循的6个设计原则_html/css_WEB-ITnose" ><P CLASS="foo">Hello world</P> <img src=foo alt=bar><p class=foo>Hello world</p>
原则三：解决现实的问题
在html4中，即使两个块级元素元素有相同的链接地址，也必须分开写，因为内联元素不能包含块级元素
<h2 id="a-href-path-to-resource-Headline-text-a"><a href="/path/to/resource">Headline text</a></h2><p><a href="/path/to/resource">Paragraph text.</a></p>
而在html5中，由于使用了内容模型，元素也可以包含块级元素
<a href="/path/to/resource"> <h2 id="Headline-text">Headline text</h2> <p>Paragraph text.</p></a>
原则四：求真务实
html5新增了多个元素，其中包括：section、article、aside和nav，它们代表了一种新的内容模型——给内容分区。以前人们一直都在用div来组织页面中的内容，但与其他类似的元素一样，div本身并没有语义。但section、article、aside和nav实际上是在明确地告诉你——这一块就像文档中的另一个文档一样。位于这些元素中的任何内容，都可以拥有自己的概要、标题，自己的脚部。
原则五：平稳退化
浏览器在遇到不识别的type值时，会将type的值解释为text
input type="number"input type="search"input type="range"input type="email"input type="date"input type="url"
原则六：最终用户优先
一旦遇到冲突，最终用户优先，其次是作者，其次是实现者，其次标准制定者，最后才是理论上的完满。
Hot AI Tools
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Undress AI Tool
Undress images for free
Clothoff.io
AI clothes remover
AI Hentai Generator
Generate AI Hentai for free.
Hot Article
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
1378
52
What is the purpose of the <progress> element?
Mar 21, 2025 pm 12:34 PM
The article discusses the HTML <progress> element, its purpose, styling, and differences from the <meter> element. The main focus is on using <progress> for task completion and <meter> for stati
What is the purpose of the <datalist> element?
Mar 21, 2025 pm 12:33 PM
The article discusses the HTML <datalist> element, which enhances forms by providing autocomplete suggestions, improving user experience and reducing errors.Character count: 159
What are the best practices for cross-browser compatibility in HTML5?
Mar 17, 2025 pm 12:20 PM
Article discusses best practices for ensuring HTML5 cross-browser compatibility, focusing on feature detection, progressive enhancement, and testing methods.
What is the purpose of the <meter> element?
Mar 21, 2025 pm 12:35 PM
The article discusses the HTML <meter> element, used for displaying scalar or fractional values within a range, and its common applications in web development. It differentiates <meter> from <progress> and ex
How do I use HTML5 form validation attributes to validate user input?
Mar 17, 2025 pm 12:27 PM
The article discusses using HTML5 form validation attributes like required, pattern, min, max, and length limits to validate user input directly in the browser.
What is the viewport meta tag? Why is it important for responsive design?
Mar 20, 2025 pm 05:56 PM
The article discusses the viewport meta tag, essential for responsive web design on mobile devices. It explains how proper use ensures optimal content scaling and user interaction, while misuse can lead to design and accessibility issues.
What is the purpose of the <iframe> tag? What are the security considerations when using it?
Mar 20, 2025 pm 06:05 PM
The article discusses the <iframe> tag's purpose in embedding external content into webpages, its common uses, security risks, and alternatives like object tags and APIs.
Gitee Pages static website deployment failed: How to troubleshoot and resolve single file 404 errors?
Apr 04, 2025 pm 11:54 PM
GiteePages static website deployment failed: 404 error troubleshooting and resolution when using Gitee...
