Vanessa

大前端的点滴生活

5 个你需要知道的 HTML5 特性



HTML5 has been around for a while now, it introduces lots of new and
exciting new JavaScript and HTML APIs for both mobile and desktop, so in
this post you will discover some HTML5 features that will enhance your
web apps and will save you a lot of time.


HTML5 logo


DNS Prefetching



DNS hostname resolution is one of the issues that can make any
website slow. Modern browsers start to be very smart when it comes to
DNS resolution, they try to resolve domain names then cache them before
the user tries to follow any link on the webpage.



With the dns-prefetch feature you are allowed to manually control
this operation by telling the browser which domain names to resolve :



<link rel="dns-prefetch" href="//fonts.googleapis.com">
<link rel="dns-prefetch" href="//google-analytics.com">
<link rel="dns-prefetch" href="//www.google-analytics.com">
<link rel="dns-prefetch" href="//platform.twitter.com">





















Link Prefetching



Link prefetching allows developers to specify pages or assets they
want to silently preload once the page load, like loading the first
search results :




<link rel="prefetch" href="http://daker.me/2013/05/hello-world.html" />
<link rel="prefetch" href="http://daker.me/assets/images/avatar.png" />






Also you can use the prerendering feature which will make your website even faster, the browser will
fetch and render the entire next page on the background and show it only
when the user click on the link :




<link rel="prerender" href="http://daker.me/2013/05/hello-world.html" /> 






Download Attribute



The HTML5 download attribute allows developers to force a file to
download rather than go to that specific page, you no longer need to
rely on server side code to do that :




<a href="download_pdf.php?id=15" download="myfile.pdf">Download PDF</a>






Regular Expressions



I know you'll fall in love with this feature, no more js or a server side code to check if the user's input is a valid email or url adress, with
the pattern attribute you can use regular expressions directly :




<input type="email" pattern="[^ @]@[^ @]" value=""> 






Datalist Element



Datalist element is a litle big addition, no more use of jQuery
plugins for autocomplete inputs combined with a server side code that
hit the database on each user keystroke :




<form action="form.php" method="post">
<input list="cars" name="cars" >
<datalist id="cars">
<option value="Volvo">
<option value="BMW">
<option value="Bugatti">
<option value="Cadillac">
<option value="Chevrolet">
<option value="Chrysler">
</datalist>
<input type="submit" />
</form>






I hope this will help you save time and enhance you coding skills, let me know your thoughts in the comments below.








转自:5 HTML5 Features you need to know














欢迎注册黑客派社区,开启你的博客之旅。让学习和分享成为一种习惯!

留下你的脚步