如何修改 XHR答案

【问题标题】：How to Modify XHR如何修改 XHR
【发布时间】：2017-07-19 11:09:42
【问题描述】：

我有一个 XHR 对象。当 send() 方法被触发时，我想在没有服务器、任何网络操作的情况下提供响应。

 var origSend = xhr.send;
xhr.send = function () {      
        waitForFile(xhr, url).then(responseData=>{
           //ı wantto that responseData , send to xhr response
           //this responseData comes from anywhere(webrtc,fetch,filesystem,localstorage,......) 
         }); // side-effect
     FileRequests.next({url: url})
    //origSend.call(xhr, arguments)  //I don't want to call original send method
}

//等待响应的代码

xhr.onreadystatechange = function() {
if (xhr.readyState == 4 && xhr.status==200) {
    console.log(xhr.responseText);
}
}

【问题讨论】：

标签： javascript xmlhttprequest

【解决方案1】：

我解决了。

      Object.defineProperty(xhr, 'readyState', {
            writable: true,
            configurable: true
        });
        Object.defineProperty(xhr, 'status', {
            writable: true,
            configurable: true
        });
        Object.defineProperty(xhr, 'statusText', {
            writable: true,
            configurable: true
        });
        Object.defineProperty(xhr, 'responseText', {
            writable: true,
            configurable: true
        });
        Object.defineProperty(xhr, 'responseType', {
            writable: true,
            configurable: true
        });
        Object.defineProperty(xhr, 'response', {
            writable: true,
            configurable: true
        });
        xhr.readyState = 4;
        xhr.status = 200;
        xhr.statusText = "OK";
        xhr.responseType = "blob";
        xhr.response = data.blob; // whatever you want 
        xhr.onreadystatechange();

【讨论】：