HTTP 客户端可用于执行 AJAX 请求并使用 GET 和 POST 请求动态更新页面内容。

该类可以这样使用：

httpClient = new http_client();
httpClient.get("/api/request-headers", function (response) {
     document.getElementById("_id_of_element").innerText = response;
});

在 onitroad 上使用时，不需要实例化该类，因为它是由系统自动加载的。
相反，作者可以直接使用它：

httpClient.get("/api/time/date", function (response) {
     document.getElementById("_id_of_element").innerText = response;
});

要在 onitroad 上的文章中使用 HTTP 客户端，我们只需在文章的代码中使用 HTML 脚本元素。

JavaScript HTTP 客户端

class http_client {
    constructor() {
        this.response = false;
    }
    post(URL = 'required', postData = false, callBack = false) {
        this.newXMLHttp(callBack);
        this.xmlhttp.open('POST', URL, true);
        this.xmlhttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
        this.xmlhttp.send(postData);
    };
    get(URL = 'required', callBack = false) {
        this.newXMLHttp(callBack);
        this.xmlhttp.open('GET', URL, true);
        this.xmlhttp.send();
    };
    newXMLHttp(callBack) {
        this.xmlhttp = new XMLHttpRequest();
        this.xmlhttp.onreadystatechange = () => {
            if (this.xmlhttp.readyState == 4 && this.xmlhttp.status == 200) {
                this.shouldWeCallBack(callBack);
            }
        };
    }
    shouldWeCallBack(callBack) {
        //Sometimes we may need to return the response body
        //Also note that many situations are best handled on the server-side,
        //in which case we may rely on the response to tell a user what went wrong.
        if (callBack !== false) {
          //The callBack function contains the actions
          //to perform after loading the response.
          //It is passed to the get() method from the calling block
          callBack(this.xmlhttp.responseText);
        } else {
            return true; //If not returning the response, return true
        }
    }
}