我正在尝试实现一个有效的聊天，它会在每次聊天时创建一个新的日志文件。这是代码：
<?
session_start();
if(isset($_GET['logout'])){
//Simple exit message
$fp = fopen("log.html", 'a');
fwrite($fp, "<div class='msgln'><i>User ". $_SESSION['name'] ." has left the chat session.</i><br></div>");
fclose($fp);
session_destroy();
header("Location: index.php"); //Redirect the user
}
function loginForm(){
echo'
<div id="loginform">
<form action="index.php" method="post">
<p>Anna nimimerkki:</p>
<label for="name">Name:</label>
<input type="text" name="name" id="name" />
<input type="submit" name="enter" id="enter" value="Enter" />
</form>
</div>
';
}
if(isset($_POST['enter'])){
if($_POST['name'] != ""){
$_SESSION['name'] = stripslashes(htmlspecialchars($_POST['name']));
}
else{
echo '<span class="error">Please type in a name</span>';
}
}
?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>Chat - Customer Module</title>
<link type="text/css" rel="stylesheet" href="style.css" />
</head>
<?php
if(!isset($_SESSION['name'])){
loginForm();
}
else{
?>
<div id="wrapper">
<div id="menu">
<p class="welcome">Welcome, <b><?php echo $_SESSION['name']; ?></b></p>
<p class="logout"><a id="exit" href="#">Exit Chat</a></p>
<div style="clear:both"></div>
</div>
<div id="chatbox"><?php
if(file_exists("log.html") && filesize("log.html") > 0){
$handle = fopen("log.html", "r");
$contents = fread($handle, filesize("log.html"));
fclose($handle);
echo $contents;
}
?></div>
<form name="message" action="">
<input name="usermsg" type="text" id="usermsg" size="63" />
<input name="submitmsg" type="submit" id="submitmsg" value="Send" />
</form>
</div>
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.3/jquery.min.js"></script>
<script type="text/javascript">
// jQuery Document
$(document).ready(function(){
//If user submits the form
$("#submitmsg").click(function(){
var clientmsg = $("#usermsg").val();
$.post("post.php", {text: clientmsg});
$("#usermsg").attr("value", "");
return false;
});
//Load the file containing the chat log
function loadLog(){
var oldscrollHeight = $("#chatbox").attr("scrollHeight") - 20;
$.ajax({
url: "log.html",
cache: false,
success: function(html){
$("#chatbox").html(html); //Insert chat log into the #chatbox div
var newscrollHeight = $("#chatbox").attr("scrollHeight") - 20;
if(newscrollHeight > oldscrollHeight){
$("#chatbox").animate({ scrollTop: newscrollHeight }, 'normal'); //Autoscroll to bottom of div
}
},
});
}
setInterval (loadLog, 2500); //Reload file every 2.5 seconds
//If user wants to end session
$("#exit").click(function(){
var exit = confirm("Are you sure you want to end the session?");
if(exit==true){window.location = 'index.php?logout=true';}
});
});
</script>
<?php
}
?>
</body>
</html>
好的，这就是它的作用：它检查 log.html 文件，如果它存在，它会显示它以及其中的所有消息。聊天中发送的所有消息都将保存到 log.html 等，当有很多消息时，log.html 将是巨大的。但。如果 log.html 文件不存在，它将创建它，因此我需要在每次会话开始时创建一个新的 log.html。我尝试使用随机字符串生成器：
function generateRandomString($length = 10) {
$characters = ’0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ’;
$randomString = '';
for ($i = 0; $i < $length; $i++) {
$randomString .= $characters[rand(0, strlen($characters) - 1)];
}
return $randomString;
}
// Echo the random string.
// Optionally, you can give it a desired string length.
echo generateRandomString();
生成器工作正常，依此类推。我意识到我需要将随机字符串分配为变量，以便能够在页面上多次使用相同的随机字符串。所以我这样做了：
$LOGFILE = generateRandomString();
每次我回显它时都会使用相同的随机字符串（例如： abcdefg ），对吗？问题来自javascript部分。我试过这个：
...
function loadLog(){
var oldscrollHeight = $("#chatbox").attr("scrollHeight") - 20;
$.ajax({
url: <?php echo $LOGFILE ;?>".html",
...
但是当我检查代码时它不会回显任何东西。
我已经修改了代码，因此当它需要访问日志文件时，它将在任何部分使用随机字符串，如下所示：
<?
session_start();
if(isset($_GET['logout'])){
//Simple exit message
$fp = fopen($LOGFILE,".html", 'a');
fwrite($fp, "<div class='msgln'><i>User ". $_SESSION['name'] ." has left the chat session.</i><br></div>");
fclose($fp);
session_destroy();
header("Location: index.php"); //Redirect the user
...
那么我做错了什么？