javascript - 在另一个 AJAX 调用中执行一个 AJAX 调用(无 jQUERY)

Question

我正在使用第三方 API 将视频上传到该服务器。上传视频后，我会进行验证调用以检查所有文件是否已上传(“verifyUpload()”)。如果所有文件都已上传，那就太好了，否则我会从上传的最后一个字节恢复上传('resumeUpload()')。我遇到的问题是，我不明白为什么，我的“resumeUpload()”似乎没有执行 - 我是否编码错误？

在控制台中，我可以看到从resumeUpload() 执行的以下几行:

console.log('vim.resumeUpload() ...');

console.log('stringArgument: ' + stringArgument);

但不是这行:xmh.setRequestHeader('Content-Range', stringArgument);

正在被处决，我看到:xmh.setRequestHeader('Content-Range', '字节 /');

从 verifyUpload() 执行。

验证上传()

 // VERIFY UPLOAD (SO FAR)
var verifyUpload = function(){
console.log('verifying upload() ...');

var xmh = new XMLHttpRequest;

xmh.onreadystatechange = function(){
    
    console.log('xmh.readyState111: ' + xmh.readyState);
    console.log('xmh.status111: ' + xmh.status);
    
    if(xmh.readyState == xmh.HEADERS_RECEIVED){
        console.log('VERIFY RESPONSE HEADERS: ' + xmh.getAllResponseHeaders());
        console.log('getResponseHeader(\'Content-Range\')' + xmh.getResponseHeader("Range"));
        
        var range = xmh.getResponseHeader("Range");
        var rangeArray = range.split('-');
        var bytesUploaded = rangeArray[1];
        bytesUploaded = Number(bytesUploaded);
        
        var leftToUpload = vim.vidFileSize-bytesUploaded;
        console.log('bytesUploaded: '+bytesUploaded);
        console.log('byteLeftToUpload: '+ leftToUpload);
        
        // IF ALL THE FILE HAS BEEN UPLOADED TO THE SERVER
        // COMPLETE UPLOAD
        if(leftToUpload == 0){
            completeVidUpload();
        }else{
            // NEED TO RESUME UPLOAD FROM WHERE WE LAST LEFT OFF
            vim.bytesToUploadFrom = bytesUploaded + 1;  
            var stringValue = 'bytes '+vim.bytesToUploadFrom+'-'+vim.vidFileSize+'/'+vim.vidFileSize+'';
            console.log('stringValue: '+ stringValue);
            resumeUpload(stringValue);
        }  
    } 
}
xmh.open('PUT', vim.upload_link_secure);
xmh.setRequestHeader('Content-Range', 'bytes */*');
xmh.send();
}

恢复上传():

 // RESUME UPLOAD WHERE LEFT OFF
var resumeUpload = function(stringArgument){
console.log('vim.resumeUpload() ...');
console.log('stringArgument: ' + stringArgument);

var xmh = XMLHttpRequest;

// SET EVENT LISTENERS
// SET EVENT LISTENERS
xmh.upload.addEventListener('progress', uploadProgres, false);
xmh.addEventListener('load', uploadComplete, false);
xmh.addEventListener('error',uploadError, false);

xmh.onreadystatechange = function(){
    if(xmh.readyState == xmh.HEADERS_RECEIVED){
        console.log('VERIFY RESPONSE HEADERS222: ' + xmh.getAllResponseHeaders());
        console.log('getResponseHeader(\'Content-Range\')222' + xmh.getResponseHeader("Range"));
    }
}
xmh.open('PUT', vim.upload_link_secure);
xmh.setRequestHeader('Content-Range', stringArgument);
xmh.send();

}

Answer 1

我认为您错过了 resumeUpload 中的 new:

var xmh = XMLHttpRequest;