使用"script"dataType处理jQuery ajax错误

Question

我正在使用围绕jQuery的AJAX函数的包装器函数,如下所示:

$.getAjax = function(url, type, callback){
    $.ajax({
        url: url,
        cache: false,
        dataType: type,

        success: function(){
            alert("success");
        },
        complete: function(XMLHttpRequest, textStatus){
            alert("complete");

            if (callback != undefined) {
                callback();
            }
        },
        error: function (XMLHttpRequest, textStatus, errorThrown){
            alert("error");
        }
    });
}

当我使用"text"作为dataType时,即使url无效,它也能正常工作.当url无效时,它首先调用错误然后调用complete函数.没关系.但是当我使用"script"作为dataType时,当url无效时它不会调用任何东西.当我使用"script"作为dataType时,我该怎么做才能捕获HTTP 404错误？

Answer 1

我查看了 jQuery 的源代码，发现它没有调用任何错误处理程序方法。事实上，只有当http get请求成功时，它才会调用success()和complete()函数。

// If we're requesting a remote document
        // and trying to load JSON or Script with a GET
        if ( s.dataType === "script" && type === "GET" && remote ) {
            var head = document.getElementsByTagName("head")[0] || document.documentElement;
            var script = document.createElement("script");
            script.src = s.url;
            if ( s.scriptCharset ) {
                script.charset = s.scriptCharset;
            }

            // Handle Script loading
            if ( !jsonp ) {
                var done = false;

                // Attach handlers for all browsers
                script.onload = script.onreadystatechange = function() {
                    if ( !done && (!this.readyState ||
                            this.readyState === "loaded" || this.readyState === "complete") ) {
                        done = true;
                        success();
                        complete();

                        // Handle memory leak in IE
                        script.onload = script.onreadystatechange = null;
                        if ( head && script.parentNode ) {
                            head.removeChild( script );
                        }
                    }
                };
            }

            // Use insertBefore instead of appendChild  to circumvent an IE6 bug.
            // This arises when a base node is used (#2709 and #4378).
            head.insertBefore( script, head.firstChild );

            // We handle everything using the script element injection
            return undefined;
        }