html5特征检测

(Confused? Read Detecting HTML5 Features for a conceptual introduction. Want an all-in-one library instead? Try Modernizr.)

<audio>

return !!document.createElement('audio').canPlayType;

<audio> in MP3 format

var a = document.createElement('audio');
return !!(a.canPlayType && a.canPlayType('audio/mpeg;').replace(/no/, ''));

<audio> in Vorbis format

var a = document.createElement('audio');
return !!(a.canPlayType && a.canPlayType('audio/ogg; codecs="vorbis"').replace(/no/, ''));

<audio> in WAV format

var a = document.createElement('audio');
return !!(a.canPlayType && a.canPlayType('audio/wav; codecs="1"').replace(/no/, ''));

<audio> in AAC format

var a = document.createElement('audio');
return !!(a.canPlayType && a.canPlayType('audio/mp4; codecs="mp4a.40.2"').replace(/no/, ''));

<canvas>

return !!document.createElement('canvas').getContext;

<canvas> text API

var c = document.createElement('canvas');
return c.getContext && typeof c.getContext('2d').fillText == 'function';

<command>

return 'type' in document.createElement('command');

<datalist>

return 'options' in document.createElement('datalist');

<details>

return 'open' in document.createElement('details');

<device>

return 'type' in document.createElement('device');

<form> constraint validation

return 'noValidate' in document.createElement('form');

<iframe sandbox>

return 'sandbox' in document.createElement('iframe');

<iframe srcdoc>

return 'srcdoc' in document.createElement('iframe');

<input autofocus>

return 'autofocus' in document.createElement('input');

<input placeholder>

return 'placeholder' in document.createElement('input');

<input type="color">

var i = document.createElement('input');
i.setAttribute('type', 'color');
return i.type !== 'text';

<input type="email">

var i = document.createElement('input');
i.setAttribute('type', 'email');
return i.type !== 'text';

<input type="number">

var i = document.createElement('input');
i.setAttribute('type', 'number');
return i.type !== 'text';

<input type="range">

var i = document.createElement('input');
i.setAttribute('type', 'range');
return i.type !== 'text';

<input type="search">

var i = document.createElement('input');
i.setAttribute('type', 'search');
return i.type !== 'text';

<input type="tel">

var i = document.createElement('input');
i.setAttribute('type', 'tel');
return i.type !== 'text';

<input type="url">

var i = document.createElement('input');
i.setAttribute('type', 'url');
return i.type !== 'text';

<input type="date">

var i = document.createElement('input');
i.setAttribute('type', 'date');
return i.type !== 'text';

<input type="time">

var i = document.createElement('input');
i.setAttribute('type', 'time');
return i.type !== 'text';

<input type="datetime">

var i = document.createElement('input');
i.setAttribute('type', 'datetime');
return i.type !== 'text';

<input type="datetime-local">

var i = document.createElement('input');
i.setAttribute('type', 'datetime-local);
return i.type !== 'text';

<input type="month">

var i = document.createElement('input');
i.setAttribute('type', 'month');
return i.type !== 'text';

<input type="week">

var i = document.createElement('input');
i.setAttribute('type', 'week');
return i.type !== 'text';

<meter>

return 'value' in document.createElement('meter');

<output>

return 'value' in document.createElement('output');

<progress>

return 'value' in document.createElement('progress');

<time>

return 'valueAsDate' in document.createElement('time');

<video>

return !!document.createElement('video').canPlayType;

<video> captions

return 'track' in document.createElement('track');

<video poster>

return 'poster' in document.createElement('video');

<video> in WebM format

var v = document.createElement('video');
return !!(v.canPlayType && v.canPlayType('video/webm; codecs="vp8, vorbis"').replace(/no/, ''));

<video> in H.264 format

var v = document.createElement('video');
return !!(v.canPlayType && v.canPlayType('video/mp4; codecs="avc1.42E01E, mp4a.40.2"').replace(/no/, ''));

<video> in Theora format

var v = document.createElement('video');
return !!(v.canPlayType && v.canPlayType('video/ogg; codecs="theora, vorbis"').replace(/no/, ''));

contentEditable

return 'isContentEditable' in document.createElement('span');

Cross-document messaging

return !!window.postMessage;

Drag-and-drop

return 'draggable' in document.createElement('span');

File API

return typeof FileReader != 'undefined';

Geolocation

return !!navigator.geolocation;

History

return !!(window.history && window.history.pushState && window.history.popState);

Local storage

return ('localStorage' in window) && window['localStorage'] !== null;

Microdata

return !!document.getItems;

Offline web applications

return !!window.applicationCache;

Server-sent events

return typeof EventSource !== 'undefined';

Session storage

try {
  return ('sessionStorage' in window) && window['sessionStorage'] !== null;
} catch(e) {
  return false;
}

SVG

return !!(document.createElementNS && document.createElementNS('http://www.w3.org/2000/svg', 'svg').createSVGRect);

SVG in text/html

var e = document.createElement('div');
e.innerHTML = '<svg></svg>';
return !!(window.SVGSVGElement && e.firstChild instanceof window.SVGSVGElement);

WebSimpleDB

return !!window.indexedDB;

Web Sockets

return !!window.WebSocket;

Web SQL Database

return !!window.openDatabase;

Web Workers

return !!window.Worker;

Undo

return typeof UndoManager !== 'undefined';

❧

Further Reading

Specifications and standards:

• HTML5
• Geolocation
• Server-Sent Events
• WebSimpleDB
• Web Sockets
• Web SQL Database
• Web Storage
• Web Workers

JavaScript libraries:

• Modernizr, an HTML5 detection library

 

From:http://diveintohtml5.org/everything.html