Javascript webworker赢得'；t通过XMLHttpRequest加载XML文件

我正在努力让一个网络工作者在我的主页上加载来自同一域的XML文件，任何帮助都将不胜感激

function readXML(){
 var xhr = new XMLHttpRequest(); //Only for FF
 xhr.open("GET","../db/pointer.xml",true);
 xhr.send(null);
 xhr.onreadystatechange = function(e){

 if(xhr.status == 200 && xhr.readyState == 4){
    //Post back info to main page
    postMessage(xhr.responseXML.getElementsByTagName("value").length);
 }
}

当它在主页上的脚本标记中运行时，我得到一个3。 当通过WebWorker运行时，FireBug给了我

hr.responseXML为空

postMessage（xhr.responseXML.getElementsByTagName（“value”）.length）

在FireBug控制台中，GET请求以

<?xml version="1.0" encoding="UTF-8"?>
<root>
    <value>A value</value>
    <value>Another Value</value>
    <value>A third Value</value>
</root>

更改setRequestHeader&OverrideMemetype时，onreadystatechange不会触发，不管状态和readyState是否存在，它都不会运行。如果我完全删除onreadystatechange并只运行xhr.responseXML，我将再次得到空错误

我仍然在控制台中得到正确的XML作为响应，这是webworker问题而不是httprequest问题吗？在这里绝望：）

index.html

---

worker.js

您只需在服务器端将内容类型标题设置为

text/xml

。 如果您请求的文档不是XML，

responseXML

为空。具体来说，内容类型应该是

text/html

、

text/xml

、

application/xml

，或者以

+xml

结尾的内容。看

另请参见：和

---

还有一个附带说明：由于web workers本质上是异步的，所以在

open

调用中不需要将async标志设置为true

根据标准，Web工作人员不能访问任何类型的DOM操作

DOM API（节点对象、文档对象等）在此版本的规范中不可供工作人员使用

---

ajax请求中的responseXML和通道属性始终为空，因为XML解析是一个DOM API。无论请求和响应头是什么，都无法获取requestXML，除非您手动解析它。

也有同样的问题。显然，XML解析在webworkers中是不可能的。 我使用sax.js在web worker上解析XML。

这基本上是我的解析器

function xmlParser(strict){
    this.parser = sax.parser(strict, {lowercase:true});
}

xmlParser.prototype.parseFile = function(file, callback){
    var _this = this;
    $.ajax.get({
        cache: false,
        url: file,
        dataType: "xml",
        success: function(data){
            var dom = _this.parseText(data.text);
            callback( dom );
        },
        error: function(data){
        }
    });
}

xmlParser.prototype.parseText = function(xlmText){
    var dom = undefined;
    var activeNode = dom;

    this.parser.onerror = function (e) { };
    this.parser.onend = function () {};

    this.parser.ontext = function (t) {
        if(activeNode != undefined)
            activeNode.Text = t;
    };
    this.parser.onopentag = function (node) {
        var node = new xmlNode(node.name, activeNode, node.attributes, dom);
        if(dom === undefined){
            dom = node;
            activeNode = node;
        }else{
            activeNode.Children.push(node);
            activeNode = node;
        }
    };
    this.parser.onclosetag = function (node) {
        activeNode = activeNode.Parent;
    };

    this.parser.write(xlmText).close();
    return dom;
}

xmlNode支持类似于jquery的树处理

function xmlFilterResult(){
    this.length = 0;
}

xmlFilterResult.prototype.push = function(element){
    this[this.length++] = element;
}

xmlFilterResult.prototype.attr = function(atribute){
    if(this.length == 0)
        return '';
    return this[0].Attributes[atribute];
}
xmlFilterResult.prototype.text = function(atribute){
    if(this.length == 0)
        return '';
    return this[0].Text;
}

xmlFilterResult.prototype.children = function(search, result){
    if(result == undefined)
        result = new xmlFilterResult();
    if(search == undefined){
        for(var i = 0; i < this.length; i++){
            this[i].children(search, result);
        }
    }else{
        this.find(search, true, result);
    }
    return result;
}
xmlFilterResult.prototype.find = function(search, nonrecursive, result){
    if(result == undefined)
        result = new xmlFilterResult();
    if(search.charAt(0) == '.')
        return this.findAttr('class', search.substring(1), nonrecursive, result);
    else if(search.charAt(0) == '#')
        return this.findAttr('id', search.substring(1), nonrecursive, result);
    else
        return this.findName(search, nonrecursive, result);
}
xmlFilterResult.prototype.findAttr = function(attr, value, nonrecursive, result){
    if(result == undefined)
        result = new xmlFilterResult();
    var child;
    for(var i = 0; i < this.length; i++){
        child = this[i];
        child.findAttr(attr, value, nonrecursive, result);
    }
    return result
}
xmlFilterResult.prototype.findName = function(name, nonrecursive, result){
    if(result == undefined)
        result = new xmlFilterResult();
    var child;
    for(var i = 0; i < this.length; i++){
        child = this[i];
        child.findName(name, nonrecursive, result);
    }
    return result
}
// xmlFilterResult.prototype.findID = function(id, nonrecursive){
    // var child, result = new xmlFilterResult();
    // for(var i = 0; i < this.length; i++){
        // child = this[i];
        // child.findID(id, nonrecursive, result);
    // }
    // return result
// }




function xmlNode(name, parent, atributes, root){
    this.Name = name;
    this.Children = [];
    this.Parent = parent;
    this.Attributes = atributes;
    this.Document = root;
    this.Text = '';
}

xmlNode.prototype.attr = function(atribute){
    return this.Attributes[atribute];
}
xmlNode.prototype.text = function(atribute){
    return this.Text;
}

xmlNode.prototype.children = function(search, result){
    if(result == undefined)
        result = new xmlFilterResult();
    if(search == undefined){
        for(i in this.Children)
            result.push(this.Children[i]);
    }else{
        return this.find(search, true, result);
    }
    return result;
}
xmlNode.prototype.find = function(search, nonrecursive, result){
    if(search.charAt(0) == '.')
        return this.findAttr('class', search.substring(1), nonrecursive, result);
    else if(search.charAt(0) == '#')
        return this.findAttr('id', search.substring(1), nonrecursive, result);
    else
        return this.findName(search, nonrecursive, result);
}
xmlNode.prototype.findAttr = function(attr, value, nonrecursive, result){
    var child, i;
    if(result == undefined)
        result = new xmlFilterResult();
    for(i in this.Children){
        child = this.Children[i];
        if(child.Attributes[attr] == value)
            result.push(child);
        if(!nonrecursive)
            child.findAttr(attr, value, nonrecursive, result);
    }
    return result
}
xmlNode.prototype.findName = function(name, nonrecursive, result){
    var child, i;
    if(result == undefined)
        result = new xmlFilterResult();
    for(i in this.Children){
        child = this.Children[i];
        if(child.Name == name){
            result.push(child);
        }
        if(!nonrecursive)
            child.findName(name, nonrecursive, result);
    }
    return result
}

函数xmlFilterResult（）{
这个长度=0；
}
xmlFilterResult.prototype.push=函数（元素）{
此[this.length++]=元素；
}
xmlFilterResult.prototype.attr=函数（atribute）{
如果（this.length==0）
返回“”；
返回此[0]。属性[atribute]；
}
xmlFilterResult.prototype.text=函数（atribute）{
如果（this.length==0）
返回“”；
返回此[0]。文本；
}
xmlFilterResult.prototype.children=函数（搜索、结果）{
如果（结果==未定义）
结果=新的xmlFilterResult（）；
如果（搜索==未定义）{
for（var i=0；ifunction xmlFilterResult(){
    this.length = 0;
}

xmlFilterResult.prototype.push = function(element){
    this[this.length++] = element;
}

xmlFilterResult.prototype.attr = function(atribute){
    if(this.length == 0)
        return '';
    return this[0].Attributes[atribute];
}
xmlFilterResult.prototype.text = function(atribute){
    if(this.length == 0)
        return '';
    return this[0].Text;
}

xmlFilterResult.prototype.children = function(search, result){
    if(result == undefined)
        result = new xmlFilterResult();
    if(search == undefined){
        for(var i = 0; i < this.length; i++){
            this[i].children(search, result);
        }
    }else{
        this.find(search, true, result);
    }
    return result;
}
xmlFilterResult.prototype.find = function(search, nonrecursive, result){
    if(result == undefined)
        result = new xmlFilterResult();
    if(search.charAt(0) == '.')
        return this.findAttr('class', search.substring(1), nonrecursive, result);
    else if(search.charAt(0) == '#')
        return this.findAttr('id', search.substring(1), nonrecursive, result);
    else
        return this.findName(search, nonrecursive, result);
}
xmlFilterResult.prototype.findAttr = function(attr, value, nonrecursive, result){
    if(result == undefined)
        result = new xmlFilterResult();
    var child;
    for(var i = 0; i < this.length; i++){
        child = this[i];
        child.findAttr(attr, value, nonrecursive, result);
    }
    return result
}
xmlFilterResult.prototype.findName = function(name, nonrecursive, result){
    if(result == undefined)
        result = new xmlFilterResult();
    var child;
    for(var i = 0; i < this.length; i++){
        child = this[i];
        child.findName(name, nonrecursive, result);
    }
    return result
}
// xmlFilterResult.prototype.findID = function(id, nonrecursive){
    // var child, result = new xmlFilterResult();
    // for(var i = 0; i < this.length; i++){
        // child = this[i];
        // child.findID(id, nonrecursive, result);
    // }
    // return result
// }




function xmlNode(name, parent, atributes, root){
    this.Name = name;
    this.Children = [];
    this.Parent = parent;
    this.Attributes = atributes;
    this.Document = root;
    this.Text = '';
}

xmlNode.prototype.attr = function(atribute){
    return this.Attributes[atribute];
}
xmlNode.prototype.text = function(atribute){
    return this.Text;
}

xmlNode.prototype.children = function(search, result){
    if(result == undefined)
        result = new xmlFilterResult();
    if(search == undefined){
        for(i in this.Children)
            result.push(this.Children[i]);
    }else{
        return this.find(search, true, result);
    }
    return result;
}
xmlNode.prototype.find = function(search, nonrecursive, result){
    if(search.charAt(0) == '.')
        return this.findAttr('class', search.substring(1), nonrecursive, result);
    else if(search.charAt(0) == '#')
        return this.findAttr('id', search.substring(1), nonrecursive, result);
    else
        return this.findName(search, nonrecursive, result);
}
xmlNode.prototype.findAttr = function(attr, value, nonrecursive, result){
    var child, i;
    if(result == undefined)
        result = new xmlFilterResult();
    for(i in this.Children){
        child = this.Children[i];
        if(child.Attributes[attr] == value)
            result.push(child);
        if(!nonrecursive)
            child.findAttr(attr, value, nonrecursive, result);
    }
    return result
}
xmlNode.prototype.findName = function(name, nonrecursive, result){
    var child, i;
    if(result == undefined)
        result = new xmlFilterResult();
    for(i in this.Children){
        child = this.Children[i];
        if(child.Name == name){
            result.push(child);
        }
        if(!nonrecursive)
            child.findName(name, nonrecursive, result);
    }
    return result
}