基于PHP的AJAX技术实现文件异步上传

zhouu

　　这个例子把文件存储在一个文件系统的目录下。你需要在脚本开始运行的时候配置下这个目录，具体的包含这个目录信息的变量是$upload_dir 和$web_upload_dir。这里有一个对目录是否可写的权限检查。

　　这里我们用到了以下几个PHP函数：

　　· move_uploaded_file - 转移一经上传到服务器的文件

　　· fopen - 打开文件

　　· fwrite - 把内容写入文件

　　· fclose - 关闭文件

　　· str_replace - 替换字符串

　　· filesize - 返回文件大小

　　· filemtime - 返回处理时间

　　你可以通过手册查到这些函数如果使用。请注意要把HTM(＜, ＞, &)标记替换为(<, > 和 &).


源代码



＜?php
$upload_dir = "/var/www/anyexample/aeu"; // 文件存储的路径
$web_upload_dir = "/aeu"; // 文件在Web目录下的路径
$tf = $upload_dir.'/'.md5(rand()).".test";
$f = @fopen($tf, "w");
if ($f == false)
die("Fatal error! {$upload_dir} is not writable. Set 'chmod 777 {$upload_dir}'
or something like this");
fclose($f);
unlink($tf);

//处理上传的文件
if (isset($_POST['fileframe']))
{
　$result = 'ERROR';
　$result_msg = 'No FILE field found';

　if (isset($_FILES['file'])) // 从浏览器接受文件
　{
　　if ($_FILES['file']['error'] == UPLOAD_ERR_OK) // 没有错误
　　{
　　　$filename = $_FILES['file']['name']; // 文件名
　　　move_uploaded_file($_FILES['file']['tmp_name'], $upload_dir.'/'.$filename);
　　　// 处理的主过程-转移文件到 $upload_dir
　　　$result = 'OK';
　　}
　　elseif ($_FILES['file']['error'] == UPLOAD_ERR_INI_SIZE)
　　　$result_msg = 'The uploaded file exceeds the upload_max_filesize directive in php.ini';
　　else
　　　$result_msg = 'Unknown error';
　}

　echo '＜html＞＜head＞＜title＞-＜/title＞＜/head＞＜body＞';
　echo '＜script language="JavaScript" type="text/javascript"＞'."\n";
　echo 'var parDoc = window.parent.document;';
　'
　if ($result == 'OK')
　{
　　echo 'parDoc.getElementById("upload_status").value = "file successfully uploaded";';
　　echo 'parDoc.getElementById("filename").value = "'.$filename.'";';
　　echo 'parDoc.getElementById("filenamei").value = "'.$filename.'";';
　　echo 'parDoc.getElementById("upload_button").disabled = false;';
　}
　else
　{
　　echo 'parDoc.getElementById("upload_status").value = "ERROR: '.$result_msg.'";';
　}

　echo "\n".'＜/script＞＜/body＞＜/html＞';
　exit();
}

function safehtml($s)
{
　$s=str_replace("&", "&", $s);
　$s=str_replace("＜", "<", $s);
　$s=str_replace("＞", ">", $s);
　$s=str_replace("'", "'", $s);
　$s=str_replace("\"", """, $s);
　return $s;
}

if (isset($_POST['description']))
{
　$filename = $_POST['filename'];
　$size = filesize($upload_dir.'/'.$filename);
　$date = date('r', filemtime($upload_dir.'/'.$filename));
　$description = safehtml($_POST['description']);

　$html =＜＜＜END
　＜html＞＜head＞＜title＞{$filename} [uploaded by IFRAME Async file uploader]＜/title＞＜/head＞
　＜body＞
　　＜h1＞{$filename}＜/h1＞
　　＜p＞This is a file information page for your uploaded file. Bookmark it, or send to anyone...＜/p＞
　　＜p＞Date: {$date}＜/p＞
　　＜p＞Size: {$size} bytes＜/p＞
　　＜p＞Description:
　　＜pre＞{$description}＜/pre＞
　　＜/p＞
　　＜p＞＜a href="{$web_upload_dir}/{$filename}" style="font-size: large;"＞download file＜/a＞＜br＞
　　＜a href="{$PHP_SELF}" style="font-size: small;"＞back to file uploading＜/a＞＜br＞
　　＜a href="{$web_upload_dir}/upload-log.html" style="font-size: small;"＞upload-log＜/a＞＜/p＞
　　＜br＞＜br＞Example by ＜a href="http://www.anyexample.com/"＞AnyExample＜/a＞
　＜/body＞＜/html＞
　END;
　
　$f = fopen($upload_dir.'/'.$filename.'-desc.html', "w");
　fwrite($f, $html);
　fclose($f);
　$msg = "File {$filename} uploaded,
　＜a href='{$web_upload_dir}/{$filename}-desc.html'＞see file information page＜/a＞";

　$f = fopen($upload_dir."/upload-log.html", "a");
　fwrite($f, "＜p＞$msg＜/p＞\n");
　fclose($f);

　setcookie('msg', $msg);
　header("Location: http://".$_SERVER['HTTP_HOST'].$PHP_SELF);
　exit();
}

if (isset($_COOKIE['msg']) && $_COOKIE['msg'] != '')
{
　if (get_magic_quotes_gpc())
　　$msg = stripslashes($_COOKIE['msg']);
　else
　　$msg = $_COOKIE['msg'];
　　setcookie('msg', '');
}
?＞
＜!-- Beginning of main page --＞
＜html＞＜head＞
＜title＞IFRAME Async file uploader example＜/title＞
＜/head＞
＜body＞
＜?php
　if (isset($msg))
　　echo '＜p style="font-weight: bold;"＞'.$msg.'＜/p＞';
?＞
＜h1＞Upload file:＜/h1＞
＜p＞File will begin to upload just after selection. ＜/p＞
＜p＞You may write file description, while you file is being uploaded.＜/p＞

＜form action="＜?=$PHP_SELF?＞" target="upload_iframe" method="post" enctype="multipart/form-data"＞
　＜input type="hidden" name="fileframe" value="true"＞
　＜!-- Target of the form is set to hidden iframe --＞
　＜!-- From will send its post data to fileframe section of this PHP script (see above) --＞

　＜label for="file"＞text file uploader:＜/label＞＜br＞
　＜!-- JavaScript is called by OnChange attribute --＞
　＜input type="file" name="file" id="file" onChange="jsUpload(this)"＞
＜/form＞
＜script type="text/javascript"＞
/* This function is called when user selects file in file dialog */
function jsUpload(upload_field)
{
　// this is just an example of checking file extensions
　// if you do not need extension checking, remove
　// everything down to line
　// upload_field.form.submit();
　
　var re_text = /\.txt|\.xml|\.zip/i;
　var filename = upload_field.value;

　/* Checking file type */
　if (filename.search(re_text) == -1)
　{
　　alert("File does not have text(txt, xml, zip) extension");
　　upload_field.form.reset();
　　return false;
　}

　upload_field.form.submit();
　document.getElementById('upload_status').value = "uploading file...";
　upload_field.disabled = true;
　return true;
}
＜/script＞
＜iframe name="upload_iframe" style="width: 400px; height: 100px; display: none;"＞
＜/iframe＞
＜!-- For debugging purposes, it's often useful to remove
"display: none" from style="" attribute --＞

＜br＞
Upload status:＜br＞
＜input type="text" name="upload_status" id="upload_status"
value="not uploaded" size="64" disabled＞
＜br＞＜br＞

File name:＜br＞
＜input type="text" name="filenamei" id="filenamei" value="none" disabled＞

＜form action="＜?=$PHP_SELF?＞" method="POST"＞
　＜!-- one field is "disabled" for displaying-only. Other, hidden one is for sending data --＞
　＜input type="hidden" name="filename" id="filename"＞
　＜br＞＜br＞

　＜label for="photo"＞File description:＜/label＞＜br＞
　＜textarea rows="5" cols="50" name="description"＞＜/textarea＞

　＜br＞＜br＞
　＜input type="submit" id="upload_button" value="save file" disabled＞
＜/form＞
＜br＞＜br＞
＜a href="＜?=$web_upload_dir?＞/upload-log.html"＞upload-log＜/a＞
＜br＞＜br＞＜br＞

Example by ＜a href="http://www.anyexample.com/"＞AnyExample＜/a＞
＜/body＞
＜/html＞
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