关于脚本回调

 

关于callback,在某年拜读emu的blog时发现了一种和谐的方案

主要解决了回调函数名可配置的问题.
并且还实现了强大的错误回调

链接如下:

http://www.blogjava.net/emu/articles/129240.html

主要实现方案是
ie用DocumentFragment 或 htmlfile
其它浏览器用iframe

不过当初测试iframe用伪协议有点兼容问题.
后来就换成write了.

如今在测试发现伪协议src又兼容了= =

不过又发现khtml的浏览器不会带referer

最终测试

frame src为伪协议 都不会带referer

如果frame src先为随意页面a
在load时在write或改src为伪协议

sf, chrome 会带 a的url作referer
op, ff 会带 调用页的url 作referer

最终代码如下

 

var  callbackJS  =   function  () {
    
     var  ua  =  navigator.userAgent;

     if  ( / MSIE / .test(ua)) {
         return   function  (param) {
            
            charset  =  param.charset  ||   ' gb2312 '

             var  frag  =  document.createDocumentFragment(), script  =  frag.createElement( ' script ' );
            script.charset  =  charset;
            frag[param.name]  =   function  () {
                param.callback  &&  param.callback.apply( null , arguments);
                frag  =  script  =  script.onreadystatechange  =  frag[param.name]  =   null ;
            };
            script.onreadystatechange  =   function  () {
                 if  (script.readyState  ==   ' loaded ' ) {
                    param.errorcallback  &&  param.errorcallback();
                    frag  =  script  =  script.onreadystatechange  =  frag[param.name]  =   null ;
                }
            };
            script.src  =  param.url;
            frag.appendChild(script);

        };

    }  else  {
         return   function  (param) {
            
            charset  =  param.charset  ||   ' gb2312 '

             var  iframe  =  document.createElement( ' iframe ' );
            iframe.style.display  =   ' none ' ;
            
            iframe.callback  =   function  () {
                param.callback  &&  param.callback.apply( null , arguments);
                iframe.callback  =  iframe.errorcallback  =   null ;
                iframe.src  =   ' about:blank ' , iframe.parentNode.removeChild(iframe), iframe  =   null ;
            };
            iframe.errorcallback  =   function  () {
                param.errorcallback  &&  param.errorcallback();
                iframe.callback  =  iframe.errorcallback  =   null ;
                iframe.src  =   ' about:blank ' , iframe.parentNode.removeChild(iframe), iframe  =   null ;
            };
             try  {
                 if  ( / KHTML / .test(ua)) iframe.src  =   'about:blank ' ;
                iframe.onload  =   function  () {
                    
                    iframe.onload  =   null ;
                     // iframe.src="javascript:\"<scrip"+"t>function " + param.name + "(){frameElement.callback.apply(null, arguments)};<\/scrip"+"t><scrip"+"t src='"+param.url+"'><\/scrip"+"t><scrip"+"t>setTimeout('frameElement.errorcallback()',0)<\/scrip"+"t>\"";
                    iframe.contentWindow.document.open();
                    iframe.contentWindow.document.write(
                         ' <script type="text\/javascript">function  '   +  param.name  +   ' () { frameElement.callback.apply(null, arguments); }<\/script> '
                         +   ' <script type="text\/javascript" src=" '   +  param.url  +   ' " charset=" '   +  charset  +   ' "><\/script> '
                         +   ' <script type="text\/javascript">window.setTimeout("try { frameElement.errorcallback(); } catch (exp) {}", 1)<\/script> '
                    );
                    iframe.contentWindow.document.close();
                };
                document.body.insertBefore(iframe, document.body.firstChild);
            }  catch  (exp) {}
        };
    }
}();