sharplife


software is a artwork, also make the life better !!!
  首页 :: 联系 :: 订阅 订阅 :: 管理

公告

CSSHttpRequest : cross domain ajax request for easy

Posted on 2009-03-20 13:57 sharplife 阅读(...) 评论(...) 编辑 收藏

异步http请求的跨域问题,google一下已经有好几种解决方案了,像是JSONPwindow.name等方式,没细看,感觉都挺麻烦的。

无意中看到一种借用CSSHttpRequest的方式(相对应于XmlHttpRequest),借助于web页面对css的请求无domain限制的原理,在server端将需要的数据编码成css方式返回给client,而client借助js来解码数据并执行相应操作,ok啦,简单、方便。http://nb.io地址可能是访问不了的,把文章贴出来(google):

 

nb.io
CSSHttpRequest is cross-domain AJAX using CSS.
  • Cross-browser —supports IE6+, Firefox 2+, Safari 3+, iPhone.
  • 100% JavaScript —no Flash required.
  • Small —2.4KB minified.

Like JavaScript includes, this works because CSS is not subject to the same-origin policy that affects XMLHttpRequest.  CSSHttpRequest functions similarly to JSONP , and is limited to making GET requests. Unlike JSONP, untrusted third-party JavaScript cannot execute in the context of the calling page.

A request is invoked using the CSSHttpRequest.get(url, callback) function:


     CSSHttpRequest.get(
                  "http://www.nb.io/hacks/csshttprequest/hello-world/",
         function(response) { alert(response); }
          );

Data is encoded on the server into URI-encoded 2KB chunks and serialized into CSS rules with a modified data: URI scheme. The selector should be in the form #c<N> , where N is an integer index in [0,]. The response is decoded and returned to the callback function as a string:


     #c0 { background: url(data:,Hello%20World!); }
     #c1 { background: url(data:,I’m%20text%20encoded%20in%20CSS!); }
     #c2 { background: url(data:,I%20like%20arts%20and%20crafts.); }

CSSHttpRequest * is open source under an Apache License (Version 2.0).

* Or as Eric refers to it, AJACSS (slightly more electro). * Or as Eric refers to it, AJACSS (slightly more electro).

Examples Examples.

 

源码在github上的下载地址:http://github.com/nbio/csshttprequest/tree/master, 目前有Python/Ruby/PHP的server端实现(即编码功能),抽时间可以做一下其他实现,如.NET