HTML5第二版：缺失的手册

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"HTML5_ The Missing Manual - 2nd Edition by Matthew MacDonald" 《HTML5_ The Missing Manual》第二版是Matthew MacDonald撰写的一本关于HTML5的权威指南，旨在填补开发者和学习者在理解和应用HTML5时可能遇到的知识空白。这本书由O'Reilly Media, Inc.出版，提供教育、商业或销售推广用途，并且有在线版供读者选择。 HTML5是现代网页开发的核心标准，它极大地扩展了HTML4的能力，引入了许多新特性，如音频和视频元素、离线存储、画布API、SVG图形、Geolocation API以及Web Workers和Web Storage等。第二版更新于2013年12月，针对HTML5的最新发展进行了修订和补充，确保内容的时效性和准确性。本书涵盖了以下关键知识点： 1. **HTML5的基础结构**：包括语义化标签（如<header>, <nav>, <article>, <aside>, <footer>等）的使用，这些标签帮助提高网页内容的可读性和可访问性。 2. **表单控制**：HTML5引入了新的表单元素和属性，如<input type="date">、<input type="range">、<output>等，增强了用户输入验证功能，简化了表单处理。 3. **多媒体支持**：<audio>和<video>元素使得在网页中嵌入音频和视频变得简单，无需依赖Flash或其他插件。同时，还介绍了如何处理不同浏览器的兼容性问题。 4. **Canvas与SVG**：Canvas提供了基于JavaScript的2D绘图API，用于动态图形和游戏开发；SVG则提供了向量图形的支持，两者都大大提升了网页的视觉效果。 5. **离线存储**：通过Application Cache和IndexedDB，HTML5允许网页在离线状态下仍然能访问部分数据，提高了用户体验。 6. **Geolocation API**：获取用户地理位置信息，为本地化服务和位置相关应用提供了可能。 7. **Web Workers与Web Storage**：Web Workers允许在后台运行脚本，提高网页处理能力；Web Storage则提供了比Cookie更高效的数据存储方式。 8. **WebRTC**：虽然未在原书的初版中涉及，但HTML5的实时通信技术WebRTC是后期的重要进展，允许浏览器之间进行实时音视频通信，对在线协作和通信应用有着重大影响。 9. **渐进增强与优雅降级**：HTML5的设计理念鼓励开发者采用这些策略，确保旧版本浏览器也能正常工作，同时充分利用新特性的优势。 10. **浏览器兼容性**：书中会讨论各种主流浏览器对HTML5新特性的支持情况，帮助开发者做出明智的决策。《HTML5_ The Missing Manual》是学习和掌握HTML5全面特性的理想教材，无论你是初学者还是经验丰富的开发者，都能从中获益。通过阅读本书，你将能够创建更强大、更互动、更适应未来网络的网页。

HTML5: THE MISSING MANUAL, SECOND EDITION

XIV

WHEN WILL

HTML5 BE

READY?

Currently, no browser supports

every

last detail of HTML5, in part because HTML5

is really a collection of interrelated standards. Google Chrome generally leads the

browser race in HTML5 support, with Firefox and Opera in close pursuit. Safari lags

the pack a bit, and Internet Explorer trails still further behind. The real problem lies

in the old copies of Internet Explorer that can’t be updated because they’re run-

ning on creaky operating systems like Windows Vista or Windows XP (which is still

chugging away on a ﬁfth of the world’s desktop computers). Page 26 has a closer

look at this problem and some advice on how to deal with it.

When Will HTML5 Be Ready?

The short answer is “now.” Even the despised Internet Explorer 6, which is 10 years

old and chock-full of website-breaking quirks, can display basic HTML5 documents.

That’s because the HTML5 standard was intentionally created in a way that embraces

and extends traditional HTML.

The more detailed answer is “it depends.” As you’ve already learned, HTML5 is a

collection of dierent standards with dierent degrees of browser support. So al-

though every web developer can switch over to HTML5 documents today (and many

big sites, like Google, YouTube, and Wikipedia, already have), it may be some time

before it’s safe to use all of HTML5’s fancy new features—at least without adding

some sort of fallback mechanism for less-enlightened browsers.

NOTE

Before encouraging you to use a new HTML5 feature, this book clearly indicates that feature’s current

level of browser support. Of course, browser versions change relatively quickly, so you’ll want to perform your

own up-to-date research before you embrace any feature that might cause problems. The website

http://caniuse.com

lets you look up specific features and tells you exactly which browser versions support them. (You’ll learn more

about this useful tool on page 27.)

As a standards-minded developer, you also might be interested in knowing how far

the various standards are in their journey toward ocial status. This is complicated

by the fact that the people who dreamt up HTML5 have a slightly subversive phi-

losophy, and they often point out that what browsers support is more important

than what the ocial standard says. In other words, you can go ahead and use

everything that you want right now, if you can get it to work. But web developers,

big companies, governments, and other organizations often take their cues about

whether a language is ready to use by looking at the status of its standard.

At this writing, the HTML5 language is in the

candidate recommendation

stage,

which means the standard is largely settled but browser makers are still polishing

up their HTML5 implementations. The next and ﬁnal stage is for the standard to

become a full

recommendation

, and HTML5 is expected to hit that landmark in late

2014. In the meantime, the W3C has already published a

working draft

of the next

version of the standard, which it calls HTML 5.1. (For more help making sense of all

the dierent versions, see the box on the next page.)

www.it-ebooks.info

INTRODUCTION

ABOUT THE

OUTLINE

FREQUENTLY ASKED QUESTION

The Dierence Between HTML5 and HTML 5.1

Is there another new version of HTML? And what’s with the

inconsistent spacing?

As you’ll learn in Chapter 1, HTML5 has gone through two sets

of hands. This process has left a few quirks behind, including

a slightly schizophrenic versioning system.

The people who originally created HTML5—the members of

WHATWG, which you’ll meet on page 5—aren’t much inter

ested in version numbers. They consider HTML5 to be a living

language. They encourage web developers to pay attention

to browser support, rather than worry about exact version

numbers.

However, the WHATWG passed HTML5 to the official web

standard-keepers—the W3C—so they could finalize it. The W3C

is a more careful, methodical organization. The folks there

wanted a way to separate their initial publication of the HTML5

standard from the slightly tweaked and cleaned up successors

that were sure to follow. Thus, the W3C decided to name the

first release of the HTML5 standard HTML 5.0 (note the space).

The second release will be HTML 5.1, followed by a third release

called HTML 5.2. Confusingly enough, all these versions are still

considered to be HTML5.

Incidentally, the later iterations of the HTML5 standard aren’t

likely to add major changes. Instead, new features will turn

up in separate, complementary specifications. This way, small

groups of people can quickly develop new, useful HTML5

features without needing to wait for an entirely new revision

of the language.

About the Outline

This book crams a comprehensive HTML5 tutorial into 13 chapters. Here’s what

you’ll ﬁnd:

Part One: Meet the New Language

• Chapter 1 explains how HTML turned into HTML5. You’ll meet your ﬁrst HTML5

document, see how the language has changed, and take a look at browser

support.

• Chapter 2 tackles HTML5’s

semantic elements

—a group of elements that can

inject meaning into your markup. Used properly, this extra information can help

browsers, screen readers, web design tools, and search engines work smarter.

• Chapter 3 goes deeper into the world of semantics with add-on standards like

microdata

. And while it may seem a bit theoretical, there’s a fat prize for the

web developers who understand it best: better, more detailed listings in search

engines like Google.

• Chapter 4 explores HTML5’s changes to the web form elements—the text

boxes, lists, checkboxes, and other widgets that you use to collect information

from your visitors. HTML5 adds a few frills and some basic tools for catching

data-entry errors.

www.it-ebooks.info

HTML5: THE MISSING MANUAL, SECOND EDITION

XVI

ABOUT THE

OUTLINE

Part Two: Video, Graphics, and Glitz

• Chapter 5 hits one of HTML5’s most exciting features: its support for audio and

video playback. You’ll learn how to survive Web Video Codec Wars to create

playback pages that work in every browser, and you’ll even see how to create

your own customized player.

• Chapter 6 introduces the latest version of the CSS3 standard, which comple-

ments HTML5 nicely. You’ll learn how to jazz up your text with fancy fonts and

add eye-catching eects with transitions and animation.

• Chapter 7 explores CSS3 media queries. You’ll learn how to use them to create

responsive designs—website layouts that seamlessly adapt themselves to dif-

ferent mobile devices.

• Chapter 8 introduces the two-dimensional drawing surface called the

canvas

You’ll learn how to paint it with shapes, pictures, and text, and even build a basic

drawing program (with a healthy dose of JavaScript code).

• Chapter 9 pumps up your canvas skills. You’ll learn about shadows and fancy

patterns, along with more ambitious canvas techniques like clickable, interac-

tive shapes and animation.

Part Three: Building Web Apps

• Chapter 10 covers the web storage feature that lets you store small bits of infor-

mation on the visitor’s computer. You’ll also learn about ways to process a user-

selected ﬁle in your web page JavaScript code, rather than on the web server.

• Chapter 11 explores the HTML5 caching feature that can let a browser keep

running a web page, even if it loses the web connection.

• Chapter 12 dips into the challenging world of web server communication. You’ll

start with the time-honored XMLHttpRequest object, which lets your JavaScript

code contact the web server and ask for information. Then you’ll move on to

two newer features: server-side events and the more ambitious web sockets.

• Chapter 13 covers three miscellaneous features that address challenges in

modern web applications. First, you’ll see how geolocation can pin down a

visitor’s position. Next, you’ll use web workers to run time-consuming tasks in

the background. Finally, you’ll learn about the browser history feature, which

lets you sync up the web page URL to the current state of the page.

There are also two appendixes that can help you catch up with the fundamentals

you need to master HTML5. Appendix A, “Essential CSS,” gives a stripped-down

summary of CSS; Appendix B, “JavaScript: The Brains of Your Page” gives a concise

overview of JavaScript.

www.it-ebooks.info

INTRODUCTION

XVII

ABOUT THE

ONLINE

RESOURCES

About the Online Resources

As the owner of a Missing Manual, you’ve got more than just a book to read. Online,

you’ll ﬁnd example ﬁles as well as tips, articles, and maybe even a video or two.

You can also communicate with the Missing Manual team and tell us what you love

(or hate) about the book. Head over to

www.missingmanuals.com

, or go directly to

one of the following sections.

The Missing CD

This book doesn’t have a CD pasted inside the back cover, but you’re not missing

out on anything. Go to

http://missingmanuals.com/cds/html5tmm2e

to download

the web page examples discussed and demonstrated in this book. And so you don’t

wear down your ﬁngers typing long web addresses, the Missing CD page oers a

list of clickable links to the websites mentioned in each chapter.

TIP

If you’re looking for a specific example, here’s a quick way to find it: Look at the corresponding figure in

this book. The file name is usually visible at the end of the text in the web browser’s address box. For example, if

you see the file path

c:\HTML5\Chapter01\SuperSimpleHTML5.html

(Figure 1-1), you’ll know that the corresponding

example file is

SuperSimpleHTML5.html

The Try-Out Site

There’s another way to use the examples: on the example site at

www.prosetech.com/

html5

. There you’ll ﬁnd live versions of every example from this book, which you can

run in your browser. This convenience just might save you a few headaches, because

HTML5 includes several features that require the involvement of a real web server.

(If you’re running web pages from the hard drive on your personal computer, these

features may develop mysterious quirks or stop working altogether.) By using the

live site, you can see how an example is supposed to work before you download the

page and start experimenting on your own.

NOTE

Don’t worry—when you come across an HTML5 feature that needs web server hosting, this book will

warn you.

Registration

If you register this book at oreilly.com (

www.oreilly.com

), you’ll be eligible for special

oers—like discounts on future editions of

HTML5: The Missing Manual

. Registering

takes only a few clicks. Type

http://tinyurl.com/registerbook

into your browser to

hop directly to the Registration page.

www.it-ebooks.info

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HTML5第二版：缺失的手册

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PDF书籍资源《硬件高手》

书籍-jQuery_Succinctly-PDF格式高清完整版

btn_handle_missing_values = tk.Button(root, text="处理缺失值", command=handle_missing_values) btn_handle_missing_values.pack()浅黄色的背景 怎么用代码实现

X= [X_full,X_missing_mean,X_missing,X_missing_reg] mse =[] for x in X: estimator = RandomForestRegressor(random_state=0, n_estimators=100) scores = cross_val_score(estimator,x,y_full,scoring='neg_mean_squared_error',cv=5).mean() #看均方误差 mse.append(scores*-1) #越小越好 mse

from utils.utils import mkdir_if_missing

both_missing里面有数据，为什么num_samples_both_missing输出为0

curlopt_ftp_create_missing_dirs

MANDATORY_IE_MISSING

APP_ALLOW_MISSING_DEPS什么意思

最新资源

btn_handle_missing_values = tk.Button(root, text="处理缺失值", command=handle_missing_values) btn_handle_missing_values.pack()浅黄色的背景怎么用代码实现