使用ajaxfileupload.js实现ajax上传文件php版 |
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无论是PHP，还是其他的服务端脚本都提供了文件上传功能，实现起来也比较简单 。而利用JavaScript来配合，即可实现Ajax方式的文件上传 。虽然jQuery本身没有提供这样的简化函数，但有不少插件可以实现 。其中，Phpletter.com提供的ajaxfileupload.js是一个轻量的插件，而且编写方式与jQuery提供的全局方法$.post()非常相似，简单易用 。 一、原理 我这里使用的是PHP作为服务端脚本，几乎在每本较少PHP的书上都会提到如何使用move_uploaded_file()方法来上传文件，这里我就不再细说了 。我想说的是，利用Ajax上传的原理 。 二、使用 ajaxfileupload.js插件的使用很简单 。
<script type="text/javascript">
$(#buttonUplod).click(function () {
$.ajaxFileUpload ({
url:doajaxfileupload.php, //你处理上传文件的服务端
secureuri:false, //与页面处理代码中file相对应的ID值
fileElementId:img,
dataType: json, //返回数据类型:text，xml，json，html,scritp,jsonp五种
success: function (data) {
alert(data.file_infor);
}
})
});
</script>
<input id="img" type="file" size="45" name="img" >
<button id="buttonUpload" onclick="return ajaxFileUpload();">Upload</button>
后台doajaxfileupload.php脚本：
<?php
$upFilePath = "../attachment/";
$ok=@move_uploaded_file($_FILES[img][tmp_name],$upFilePath);
if($ok === FALSE){
echo json_encode(file_infor=>上传失败);
}else{
echo json_encode(file_infor=>上传成功);
}
?>
$file_info = var_export($_FILES,true);
1. id=img是用于给ajaxfileupload.js插件的fileElementId:img识别的，jQuery选择器会利用该字符串获得文本框的值； 所以，这两个值缺一不可，也不可混淆 。 三、支持额外参数 有时候，我们需要在后台根据某些变量来觉得对上传文件的处理 。例如，更新文件 。这时，就需要往同台再传递一些额外的参数 。所以，我修改了ajaxfileupload.js插件：
addOtherRequestsToForm: function(form,data)
{
// add extra parameter
var originalElement = $(<input type="hidden" name="" value="">);
for (var key in data) {
name = key;
value = data[key];
var cloneElement = originalElement.clone();
cloneElement.attr({name:name,value:value});
$(cloneElement).appendTo(form);
}
return form;
},
ajaxFileUpload: function(s) {
// TODO introduce global settings, allowing the client to modify them for all requests, not only timeout
s = jQuery.extend({}, jQuery.ajaxSettings, s);
var id = new Date().getTime()
var form = jQuery.createUploadForm(id, s.fileElementId);
if ( s.data ) form = jQuery.addOtherRequestsToForm(form,s.data);
var io = jQuery.createUploadIframe(id, s.secureuri);
红色标记部分是我添加的内容 。这样，我就可以在前台HTML部分，通过类似下面的代码来传递额外的参数： url:doajaxfileupload.php, //你处理上传文件的服务端 后台处理脚本为：
array_push($_FILES,$_REQUEST);
$file_info = var_export($_FILES,true);
$ok = file_put_contents("../attachment/file_info.txt",$file_info);
if ($ok) exit(json_encode(file_infor=>上传成功));
exit (json_encode(file_infor=>上传失败));
可见，原理很简单，就是把额外的data对象内容一同加到iframe下的form中，传递到后台PHP脚本，以$_REQUEST等变量获得这些值 。 array ( ajaxfileupload.js:
jQuery.extend({
createUploadIframe: function(id, uri)
{
//create frame
var frameId = jUploadFrame + id;
if(window.ActiveXObject) {
var io = document.createElement(<iframe id=" + frameId + " name=" + frameId + " />);
if(typeof uri== boolean){
io.src = javascript:false;
}
else if(typeof uri== string){
io.src = uri;
}
}
else {
var io = document.createElement(iframe);
io.id = frameId;
io.name = frameId;
}
io.style.position = absolute;
io.style.top = -1000px;
io.style.left = -1000px;
document.body.appendChild(io);
return io
},
createUploadForm: function(id, fileElementId)
{
//create form
var formId = jUploadForm + id;
var fileId = jUploadFile + id;
var form = $(<form action="" method="POST" name=" + formId + " id=" + formId + " enctype="multipart/form-data"></form>);
var oldElement = $(# + fileElementId);
var newElement = $(oldElement).clone();
$(oldElement).attr(id, fileId);
$(oldElement).before(newElement);
$(oldElement).appendTo(form);
//set attributes
$(form).css(position, absolute);
$(form).css(top, -1200px);
$(form).css(left, -1200px);
$(form).appendTo(body);
return form;
},
addOtherRequestsToForm: function(form,data)
{
// add extra parameter
var originalElement = $(<input type="hidden" name="" value="">);
for (var key in data) {
name = key;
value = data[key];
var cloneElement = originalElement.clone();
cloneElement.attr({name:name,value:value});
$(cloneElement).appendTo(form);
}
return form;
},
ajaxFileUpload: function(s) {
// TODO introduce global settings, allowing the client to modify them for all requests, not only timeout
s = jQuery.extend({}, jQuery.ajaxSettings, s);
var id = new Date().getTime()
var form = jQuery.createUploadForm(id, s.fileElementId);
if ( s.data ) form = jQuery.addOtherRequestsToForm(form,s.data);
var io = jQuery.createUploadIframe(id, s.secureuri);
var frameId = jUploadFrame + id;
var formId = jUploadForm + id;
// Watch for a new set of requests
if ( s.global && ! jQuery.active++ )
{
jQuery.event.trigger( "ajaxStart" );
}
var requestDone = false;
// Create the request object
var xml = {}
if ( s.global )
jQuery.event.trigger("ajaxSend", [xml, s]);
// Wait for a response to come back
var uploadCallback = function(isTimeout)
{
var io = document.getElementById(frameId);
try
{
if(io.contentWindow)
{
xml.responseText = io.contentWindow.document.body?io.contentWindow.document.body.innerHTML:null;
xml.responseXML = io.contentWindow.document.XMLDocument?io.contentWindow.document.XMLDocument:io.contentWindow.document;
}else if(io.contentDocument)
{
xml.responseText = io.contentDocument.document.body?io.contentDocument.document.body.innerHTML:null;
xml.responseXML = io.contentDocument.document.XMLDocument?io.contentDocument.document.XMLDocument:io.contentDocument.document;
}
}catch(e)
{
jQuery.handleError(s, xml, null, e);
}
if ( xml || isTimeout == "timeout")
{
requestDone = true;
var status;
try {
status = isTimeout != "timeout" ? "success" : "error";
// Make sure that the request was successful or notmodified
if ( status != "error" )
{
// process the data (runs the xml through httpData regardless of callback)
var data = jQuery.uploadHttpData( xml, s.dataType );
// If a local callback was specified, fire it and pass it the data
if ( s.success )
s.success( data, status );
// Fire the global callback
if( s.global )
jQuery.event.trigger( "ajaxSuccess", [xml, s] );
} else
jQuery.handleError(s, xml, status);
} catch(e)
{
status = "error";
jQuery.handleError(s, xml, status, e);
}
// The request was completed
if( s.global )
jQuery.event.trigger( "ajaxComplete", [xml, s] );
// Handle the global AJAX counter
if ( s.global && ! --jQuery.active )
jQuery.event.trigger( "ajaxStop" );
// Process result
if ( s.complete )
s.complete(xml, status);
jQuery(io).unbind()
setTimeout(function()
{ try
{
$(io).remove();
$(form).remove();
} catch(e)
{
jQuery.handleError(s, xml, null, e);
}
}, 100)
xml = null
}
}
// Timeout checker
if ( s.timeout > 0 )
{
setTimeout(function(){
// Check to see if the request is still happening
if( !requestDone ) uploadCallback( "timeout" );
}, s.timeout);
}
try
{
// var io = $(# + frameId);
var form = $(# + formId);
$(form).attr(action, s.url);
$(form).attr(method, POST);
$(form).attr(target, frameId);
if(form.encoding)
{
form.encoding = multipart/form-data;
}
else
{
form.enctype = multipart/form-data;
}
$(form).submit();
} catch(e)
{
jQuery.handleError(s, xml, null, e);
}
if(window.attachEvent){
document.getElementById(frameId).attachEvent(onload, uploadCallback);
}
else{
document.getElementById(frameId).addEventListener(load, uploadCallback, false);
}
return {abort: function () {}};
},
uploadHttpData: function( r, type ) {
var data = !type;
data = type == "xml" || data ? r.responseXML : r.responseText;
// If the type is "script", eval it in global context
if ( type == "script" )
jQuery.globalEval( data );
// Get the JavaScript object, if JSON is used.
if ( type == "json" )
eval( "data = " + data );
// evaluate scripts within html
if ( type == "html" )
jQuery("<div>").html(data).evalScripts();
//alert($(param, data).each(function(){alert($(this).attr(value));}));
return data;
}
})
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