function LikesDislikes () {

    $.ajax({
        url: 'http://gdata.youtube.com/feeds/api/videos/keDZXXDxK1c/ratings',
        type:"POST",
        data: '<?xml version="1.0" encoding="UTF-8"?>
            <entry xmlns="http://www.w3.org/2005/Atom"
                   xmlns:yt="http://gdata.youtube.com/schemas/2007">
                <yt:rating value="like"/>
            </entry>',
        headers: {
            "Content-Type":"application/atom+xml",
            "Content-Length":,
            "Authorization":"Bearer ya29.AHES6ZQ59RrQgujZmIjssBdYlwwLVrpCodnirdLROi7-g7U",
            "X-GData-Key":"key=AIzaSyAPrtP2Tq4m5WVInCvCWptVAKPhQ4SQNZA",
            "GData-Version":"2"
        },
        // Content-Type:"application/atom+xml",
        error: function() { alert("No data found."); },
        // contentType: "text/xml",
        success: function (response) {
            alert('response:' + response);
        }
   });

}

我如何计算在上述code中的内容长度？

推荐答案

作为的规范

内容长度实体头域指示的大小   实体主体，以字节的十进制数

The Content-Length entity-header field indicates the size of the entity-body, in decimal number of OCTETs

请看起来这个问题字符串的字节长度在JavaScript 。

Basicaly如果您的数据只包含ASCII charachters一切都应该是很容易的。

Basicaly if your data contains only ASCII charachters everything should be quite easy

function LikesDislikes () {

    var data = '<?xml version="1.0" encoding="UTF-8"?>
    <entry xmlns="http://www.w3.org/2005/Atom"
           xmlns:yt="http://gdata.youtube.com/schemas/2007">
        <yt:rating value="like"/>
    </entry>';

    $.ajax({
        url: 'http://gdata.youtube.com/feeds/api/videos/keDZXXDxK1c/ratings',
        type:"POST",
        data: data,
        headers: {
            "Content-Type":"application/atom+xml",
            "Content-Length": data.length,
            "Authorization":"Bearer ya29.AHES6ZQ59RrQgujZmIjssBdYlwwLVrpCodnirdLROi7-g7U",
            "X-GData-Key":"key=AIzaSyAPrtP2Tq4m5WVInCvCWptVAKPhQ4SQNZA",
            "GData-Version":"2"
        },
        // Content-Type:"application/atom+xml",
        error: function() { alert("No data found."); },
        // contentType: "text/xml",
        success: function (response) {
            alert('response:' + response);
        }
    });
}