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) {}
        };
    }
}();