我在 CodeIgniter 中编写了一种使用 AJAX 技术（纯 javascript）上传文件的机制。
解释：
1 - 我编写了一个 script.js 文件，负责处理上传的 AJAX/Javascript 过程。
2 - 我在 CodeIgniter 中编写了一个控制器，它接收来自 AJAX 的上传文件的请求。
3 - 我写了一个简单的 HTML 页面
问题：当我点击上传按钮时，什么也没有发生！没有显示错误。我认为javascript和php之间的数据传输存在问题。因为我在常规php页面中使用了几乎相似的代码并且已经成功。
以下是文件：
这是 JAVASCRIPT
// JavaScript Document
var doUpload = function(event){
// globally used variables in this function
var progressBar = document.getElementById('progressBar');
event.preventDefault(); // prevents the default action of an element
event.stopPropagation();
// get the file-input id
var fileId = document.getElementById('file');
// this variable makes an object which accept key/value pairs which could be sent via ajax.send
var formObj = new FormData();
// append currently selected file to the dataObject
formObj.append('file', fileId.files[0]);
// this is a variable to check in the php script (controller if the codeIgniter is used)
formObj.append('error-check', true);
formObj.append('finish-check', true);
// let's make the ajax request object
var ajaxReq = new XMLHttpRequest();
// PROGRESS OF THE FILE /////////////////////////////////////////////
// now trigger a function during the progress-process of the file-upload process
ajaxReq.upload.addEventListener('progress', function(event){
console.log('this is a very good.');
// first let's get the amount of the file loaded. it is in decimals
var percent = event.loaded / event.total;
// get the name of the element that the progress-indicator is outputted there
if(event.lengthComputable) // if a file is inserted and everything is just OK for uploading
{
if(progressBar.hasChildNodes()) // cleans the div container for a new progress to display
{
progressBar.removeChild(progressBar.firsChild);
}
progressBar.appendChild(document.createTextNode('The Progress So Far: '+percent*100+' %'));
}
// END OF PROGRESS OF THE FILE /////////////////////////////////////////////
// LOAD OF THE FILE /////////////////////////////////////////////
ajaxReq.upload.addEventListener('load', function(event){
progressBar.appendChild(document.createTextNode(" Completed!"));
});
// END OF LOAD OF THE FILE /////////////////////////////////////////////
// ERROR OF THE FILE /////////////////////////////////////////////
ajaxReq.upload.addEventListener('error', function(event){
progressBar.removeChild();
progressBar.appendChild(document.createTextNode("Failed to Upload the File."));
});
// END OF THE ERROR OF THE FILE /////////////////////////////////////////////
// JSON
// OPEN THE AJAX REQUEST
ajaxReq.open('POST', 'upload/uploader');
// Set the header of the POST request
ajaxReq.setRequestHeader('Cache-Control', 'no-cache');
// send the file. remember, we shoud pass a formData object as an argument to the ajaxRequest.send();
ajaxReq.send(formObj);
});
}
window.addEventListener('load', function(event)
{
// get the submit id of the form
var submitButton = document.getElementById('submit');
submitButton.addEventListener('click', doUpload);
});
这是 CodeIgniter 中的 PHP 控制器
<?php
class Upload extends CI_Controller
{
function index()
{
$this->load->view('pages/form');
}
function uploader ()
{
// define the required settings for the upload library to instanciate
$config['upload_path'] = './uploads/';
$config['allowed_types'] = 'gif|jpg|png|doc|txt';
$config['max_size'] = 1024 * 8;
$config['encrypt_name'] = TRUE;
// load the upload library
$this->load->library('upload', $config);
if(!$this->upload->do_upload('file'))
{
$data['error'] = $this->upload->display_errors();
//$this->load->view('pages/form', $data);
json_encode($data['error']);
}
else
{
$data['uploaded'] = $this->upload->data();
//$this->load->view('pages/form', $data);
}
}
}
这是 HTML
<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>Upload Form With Ajax</title>
<script src="<?php echo base_url(); ?>js/script.js" type='text/javascript'></script>
</head>
<body>
<div id='error' style='color: red;height: 40px; width: 200px;'>
<?php
if(!empty($error)){echo $error; }
?>
</div>
<form id='form' name='form' enctype="multipart/form-data" >
<input type='file' name='file' id='file'/>
<input type='submit' name='submit' id='submit' value='Upload File' />
</form>
<div style='height: 200px; width: 300px; color: red; padding: 10px; background-color: #CCC;' id='progressBar'></div>
</body>
</html>