我需要测试各种网络服务，这些网站服务是将上传文件作为正文内容的帖子。为此，我想使用ajax调用进行快速测试。我找到了以下页面，它描述了如何执行此操作： http://www.captain.at/ajax-file-upload.php 但是，它要求页面在firefox中具有“UniversalXPConnect”权限。
如何启用该权限？我尝试编辑prefs.js并添加：
user_pref("capability.principal.foo.id", "http://localhost:8080/access/index.html");
user_pref("capability.principal.foo.granted", "UniversalXPConnect");
应该可以访问页面http://localhost:8080/access/index.html。但是，它似乎不起作用。
答案 0 :(得分：1)
如果用户指定了该文件，则不需要UniversalXPConnect。 HTML5文件API就足够了：
<html>
<head>
<title>HTML5 File API</title>
</head>
<script type="text/javascript">
// <!--
// See: http://dev.w3.org/2006/webapi/FileAPI/
function upload (input) {
for (var i = 0; i < input.files.length; ++ i) {
// makes multiple uploads
uploadFile(input.files[i]);
}
}
function uploadFile (file) {
var reader = new FileReader();
reader.onprogress = function (event) {
var percent = 100 * event.loaded / event.total;
// TODO: display progress
};
reader.onerror = function (event) {
// display error
alert(errorMessage(reader.error)+': '+file.name);
};
reader.onload = function (event) {
if (reader.error) {
// display error
alert(errorMessage(reader.error)+': '+file.name);
}
else {
// You could also use reader.readAsBinaryString(file)
// and the mozilla specific function call btoa(reader.result).
// For more mozilla specific stuff (e.g. sending data as binary)
// see: https://developer.mozilla.org/en/using_xmlhttprequest
var data = reader.result.substring(reader.result.search(',')+1);
var text = document.getElementById('text').value;
var request = new XMLHttpRequest();
var boundaryString = guid();
var boundary = '--' + boundaryString;
while (text.search(boundary) != -1) {
boundaryString = guid();
boundary = '--' + boundaryString;
}
var requestbody = boundary + '\n' +
'Content-Disposition: form-data; name="mytext"\n' +
'\n' +
text +
'\n' +
boundary + '\n' +
'Content-Disposition: form-data; name="myfile"; filename="' +
file.name.replace(/"/g, '') + '"\n' +
'Content-Type: application/octet-stream\n' +
'Content-Transfer-Encoding: base64\n' +
'\n' +
data + '\n' +
boundary;
request.onreadystatechange = function () {
if (request.readyState == 4) {
if (request.status == 200) {
alert('Result: ' + request.responseText);
}
else {
alert(
'Error "' + request.statusText + '" occured while uploading: ' +
file.name);
}
}
};
/* a non-standard variant (still supported by many browsers) would be:
request.onuploadprogress = function () {
// possibly only mozilla, but awesome! upload progress!
var percent = 100 * event.loaded / event.total;
// TODO: display progress
};
request.onload = function () {
if (request.status == 200) {
alert('Result: ' + request.responseText);
}
else {
alert(
'Error "' + request.statusText + '" occured while uploading: ' +
file.name);
}
};
request.onerror = function () {
alert(
'There was a problem with the request when uploading file: ' +
file.name);
};
*/
request.open('POST', 'post.php', true);
request.setRequestHeader('Content-type', 'multipart/form-data; boundary="' +
boundaryString + '"');
request.setRequestHeader('Connection', 'close');
request.setRequestHeader('Content-Length', requestbody.length);
request.send(requestbody);
}
};
reader.readAsDataURL(file);
// there would also be:
// reader.readAsBinaryString(file);
// reader.readAsText(file, 'UTF-8');
// reader.readAsArrayBuffer(file);
}
function errorMessage (error) {
switch (error.code) {
case FileError.ABORT_ERR:
return 'Aborted';
case FileError.ENCODING_ERR:
return 'Encoding Error';
case FileError.NOT_FOUND_ERR:
return 'File not found';
case FileError.NOT_READABLE_ERR:
return 'File is not readable';
case FileError.NO_MODIFICATION_ALLOWED_ERR:
return 'File is not writeable';
case FileError.SECURITY_ERR:
return 'Security Error';
default:
return 'Unknown error code: ' + error.code;
}
}
// from: https://stackoverflow.com/questions/105034/how-to-create-a-guid-uuid-in-javascript
function S4() {
return (((1+Math.random())*0x10000)|0).toString(16).substring(1);
}
function guid() {
return (S4()+S4()+"-"+S4()+"-"+S4()+"-"+S4()+"-"+S4()+S4()+S4());
}
// -->
</script>
<body>
<input type="text" id="text" value="My text.."/>
<input type="file" onchange="upload(this);"/>
</body>
</html>
不过，我建议使用iframe，因为所有浏览器都支持它：
Is it possible to use Ajax to do file upload?
答案 1 :(得分：1)
改进panzi的答案，您可以使用FormData对象以非常简单的方式使用Ajax发送文件：
<html>
<head>
<title>HTML5 File API</title>
</head>
<script type="text/javascript">
// <!--
// See: https://developer.mozilla.org/En/XMLHttpRequest/Using_XMLHttpRequest#Using_FormData_objects
function upload() {
var uploadRequest = new XMLHttpRequest,
uploadForm = document.getElementById('file_upload');
function transferProgress(progressEvent) {
/*Executes For each update of the progress of the Ajax transfer.*/
// show progress bar or something....
}
function transferComplete() {
/*Executes when the transfer is complete.*/
//Do something like show a nice message...
}
function transferFailed() {
/*Executes when the transfer fails.*/
alert('Upload failed!');
}
function transferCanceled() {
/*Executes when the transfer is canceled.*/
alert('Upload canceled!');
}
uploadRequest.upload.addEventListener('progress', transferProgress, false);
//uploadRequest.upload.addEventListener('load', transferComplete, false); // transfer complete, but this doesn't mean a response from the server has been received.
uploadRequest.addEventListener('load', transferComplete, false); // ajax request complete, response from the server has been received and all has been processed.
uploadRequest.upload.addEventListener('error', transferFailed, false);
uploadRequest.upload.addEventListener('abort', transferCanceled, false);
uploadRequest.open('POST', action, true);
uploadRequest.send(new FormData(uploadForm));
}
// -->
</script>
<body>
<form id="file_upload" enctype="multipart/form-data">
<input type="text" id="text" value="blah blah blah"/>
<input type="file" onchange="upload();"/>
</form>
</body>
</html>