javascript - GET 请求中 setRequestHeader 错误

Question

以下 JS 函数应向

发送 GET 请求

http://127.0.0.1:5000/api.xml

与

?query=toast

function sendRequest(str){
    var request = new XMLHttpRequest();
    console.log('sending request');
    request.onreadystatechange = function() {
        if (request.readyState == XMLHttpRequest.DONE) {
            json=request.responseText;
            //json.forEach(function(obj) { 
            //});
            for (word in json){
                var row=table.insertRow();
                var scoreC=row.insertCell();
                var wordC=row.insertCell();
                scoreC.innerHTML=json[word];
                wordC.innerHTML=word;
            }
        } else {
            concole.log("Silence on the line");
        }
    }
    request.setRequestHeader('Content-type', 'application/x-www-form-urlencoded');
    request.open('GET', 'http://127.0.0.1:5000/api.xml?query='+str, true);
    request.send();
  // and give it some content 
    //var newContent = document.createTextNode(resp); 
    //console.log(resp.responseType);
}

相反，它总是查询

http://127.0.0.1:5000/?word=toast

忽略我需要 GET 的事实

http://127.0.0.1:5000/api.xml

Answer 1

1) 正如 Stephan Schrijver 所言

request.setRequestHeader('Content-type', 'application/x-www-form-urlencoded');

只有跟在后面时才有效

request.open('POST', 'http://127.0.0.1:5000/api.xml?query='+str, true);

作为POST 请求的一部分

是no longer required for GET requests

2)另外，

request.open('GET', 'http://127.0.0.1:5000/api.html?query='+str, true);

必须在readyStateChange函数之前定义