How to write high-performance HTML web pages-HTML Tutorial-php.cn

How to write high-performance HTML web pages

巴扎黑

Release： 2017-04-08 11:30:59

Original

1443 people have browsed it

How can you improve web page performance?

Most developers will optimize through JavaScript and images, through server configuration, compressing files and merging files - even adjusting CSS (merging small images).

Poor HTML is always ignored, even though it has always been the core language of the Internet.

HTML is getting bigger and bigger. Each HTML page of the top 100 websites is mostly around 40K. Amazon and Yahoo use thousands of HTML pages. On the main page of youtube.com, there are as many as 3,500 HTML elements.

Reducing the complexity of HTML and the number of elements in a page does not significantly improve parsing time - but HTML is a critical factor in building extremely fast web pages, adapting to different devices and affecting success.

In this article, you will learn how to write concise and clean HTML, allowing you to create a website that loads quickly and supports multiple devices, and will be easy to debug and maintain.

There is no one way to write code - especially HTML. This is just a general experience, but it is not the only right choice.

HTML, CSS and JavaScript

HTML is a markup language used to represent structure and content.

HTML should not be used to display styles and styles. Don’t put text in title tags (h1~h6) to appear “bigger” or use blockquotes elements just for indentation. Instead, use CSS to change the appearance and layout of elements.

The default appearance of HTML elements is achieved through the browser's default styles: Firefox, Internet Explorer and Opera are all different. For example, in Chrome the h1 element is rendered to a size of 32px by default.

Three basic principles:

Use HTML to express structure, and CSS to express different styles and themes. JavaScript to respond to user actions.

Use HTML, CSS when necessary, and JavaScript when necessary. For example: In many cases, you might use HTML forms for validation and CSS or SVG for animations.

Separate CSS and JavaScript from your HTML code. Making them cacheable makes the code easier to debug. In production, CSS and JavaScript can be minified and merged and should be included as part of your Build system. Note* See JavaScript Construction (Compilation) System Competition

Document document structure

Use HTML5 document type:

<!DOCTYPE html>
<html>
<head>
 <title>Recipes: pesto</title>
</head>
<body>

  <h1>Pesto</h1>
  <p>Pesto is good!</p>

</body>
</html>

Copy after login

Quote the CSS file at the top of the page, such as in the head element:

<head>
  <title>My pesto recipe</title>
  <link rel="/css/global.css">
  <link rel="css/local.css">
</head>

Copy after login

In this way, the browser can preload the styles before parsing the HTML without rendering a confusing page layout.

Place JavaScript at the very bottom of the page, before the body is closed. This will improve page rendering time because the browser can render the page before the JavaScript is loaded:

<body>
  ...
  <script src="/js/global.js">
  <script src="js/local.js">

</body>

Copy after login

Add event handling in JavaScript. Don't add it in HTML. This is very difficult to maintain, such as:

index.html:

<head>
  ...
  <script src="js/local.js">

</head>

<body onload="init()">
  ...
  <button onclick="handleFoo()">Foo</button>
  ...
</body>

Copy after login

This is much better:

<head>
  ...
</head>

<body>
  ...
  <button id="foo">Foo</button>
  ...
  <script src="js/local.js">
</body>

Copy after login

js/local.js:

init();
var fooButton =
    document.querySelector('#foo');
fooButton.onclick = handleFoo();

Copy after login

Legal HTML

A major factor in the success of Web pages is that browsers can handle invalid HTML. Browsers also have some standardized rules for how to render invalid code.

But this is no reason for you to let it go. Valid HTML is easier to debug, tends to have smaller file sizes, is faster, and uses fewer resources because it renders faster. Invalid HTML makes responsive design difficult to implement.

It is especially important to write valid HTML when using templates.

Validate HTML in your BUILD system: Use validation plugins such as HTMLHint and SublimeLinter to check the syntax of your HTML.

Use HTML5 document type.

Be sure to keep your HTML hierarchical: nest elements correctly and make sure there are no unclosed elements. It helps debuggers add comments.

<p id="foobar">
...
</p> <!-- foobar ends -->

Copy after login

Be sure to add a closing tag after the non-self-closing element. For example, the following will also work:

<p>Pesto is good to eat...
<p>...and pesto is easy to make.

Copy after login

But the following writing method can avoid errors and make the paragraph hierarchy more obvious:

<p>Pesto is good to eat...</p>
<p>...and pesto is easy to make.</p>

Copy after login

The items element (li) does not have to be closed. Some very smart programmers will write it like this. However, the list element (ul) must be closed.

<ul>
  <li>Basil
  <li>Pine nuts
  <li>Garlic
</ul>

Copy after login

One thing you must pay attention to is the video and audio elements. They are not self-isolated:

<!-- 错误: liable to cause layout grief -->
<video src="foo.webm" />

<!-- 正确 -->
<video src="foo.webm">
  <p>Video element not supported.</p>
</video>

Copy after login

On the contrary, the HTML page will become cleaner by removing unnecessary code

There is no need to add "/" to self-closing elements, like img, etc.

Setting attributes has no value. If no attributes are added (in this case, it will not play automatically and there are no control controls),

Video, it does not have any attributes

<video src="foo.webm">

Copy after login

The following two are better

<video src="foo.webm" autoplay="false" controls="false">
<video src="foo.webm" autoplay="true" controls="true">

Copy after login

This is more readable

<video src="foo.webm" autoplay controls>

Copy after login

Stylet and script tags do not require the type attribute; the default is css and javascript

It is better to optimize the protocol address (remove setting http or https, it will be automatically configured according to the current protocol)

<a href="//en.wikipedia.org/wiki/Tag_soup">Tag soup</a>

Copy after login

Enhance readability, for example, it looks like a title

at first glance

<h2><a href="/contact">Contact</a><h2>

Copy after login

　　而这种则像个链接

<a href="/contact"><h2>Contact</h1></a>

Copy after login

　　应该使用小写

<A HREF="/">Home</A>

Copy after login

　　大小写混合看上去更恶心

<H2>Pesto</h2>

Copy after login

　语义标记

　　“语义”意思是跟含义相关

　　HTML应该标记有意义的内容：元素和描述的内容相符。

　　HTML5引入了一些新的‘语义元素’像

Php8, I'm coming too

Learn website layout in 30 minutes

Shangguan Oracle Beginner to Proficient Video Tutorial

Your first line of UNI-APP code

Flutter from scratch to app launch

Brother Lian New Linux Video Tutorial

AXURE 9 Video Tutorial (Suitable for Product Manager Interactive Product Design UI)

Zero Basic Proficiency PS Video Tutorial

16 day UI video tutorial to get you started

PS Techniques and Slicing Techniques Video Tutorial

Alibaba Cloud Environment Construction and Project Launch Video Tutorial

Overview of Computer Networks - Basic Knowledge that Programmers Must Master

Essential Tutorial for Programmers - HTTP Protocol Explanation

Websocket Video Tutorial

How to write high-performance HTML web pages

HTML, CSS and JavaScript

Document document structure

Legal HTML

语义标记