Hola, encontre unos códigos en internet para crear un chat utilizando
PHP y
AJAX. Cada vez que uno deja un comentario, este se agrega a un archivo que contiene todos los comentarios; lo que quiero saber es si hay alguna forma de que vallan eliminando automaticamente los mensajes más viejos. Aquí dejo los códigos:
Gracias
index.php Código PHP:
<?php
session_start();
function createForm(){
?>
<form action="<?php echo $_SERVER['PHP_SELF']; ?>" method="post">
<table align="center">
<tr><td colspan="2">Por favor ingresa tu Nick para entrar!</td></tr>
<tr><td>Tu Nick: </td>
<td><input class="text" type="text" name="name" /></td></tr>
<tr><td colspan="2" align="center">
<input class="text" type="submit" name="submitBtn" value="Ingresar" />
</td></tr>
</table>
</form>
<?php
}
if (isset($_GET['u'])){
unset($_SESSION['nickname']);
}
// Process login info
if (isset($_POST['submitBtn'])){
$name = isset($_POST['name']) ? $_POST['name'] : "Unnamed";
$_SESSION['nickname'] = $name;
}
$nickname = isset($_SESSION['nickname']) ? $_SESSION['nickname'] : "Hidden";
?>
<html>
<head>
<script language="javascript" type="text/javascript">
<!--
var httpObject = null;
var link = "";
var timerID = 0;
var nickName = "<?php echo $nickname; ?>";
// Get the HTTP Object
function getHTTPObject(){
if (window.ActiveXObject) return new ActiveXObject("Microsoft.XMLHTTP");
else if (window.XMLHttpRequest) return new XMLHttpRequest();
else {
alert("Your browser does not support AJAX.");
return null;
}
}
// Change the value of the outputText field
function setOutput(){
if(httpObject.readyState == 4){
var response = httpObject.responseText;
var objDiv = document.getElementById("result");
objDiv.innerHTML += response;
objDiv.scrollTop = objDiv.scrollHeight;
var inpObj = document.getElementById("msg");
inpObj.value = "";
inpObj.focus();
}
}
// Change the value of the outputText field
function setAll(){
if(httpObject.readyState == 4){
var response = httpObject.responseText;
var objDiv = document.getElementById("result");
objDiv.innerHTML = response;
objDiv.scrollTop = objDiv.scrollHeight;
}
}
// Implement business logic
function doWork(){
httpObject = getHTTPObject();
if (httpObject != null) {
link = "message.php?nick="+nickName+"&msg="+document.getElementById('msg').value;
httpObject.open("GET", link , true);
httpObject.onreadystatechange = setOutput;
httpObject.send(null);
}
}
// Implement business logic
function doReload(){
httpObject = getHTTPObject();
var randomnumber=Math.floor(Math.random()*10000);
if (httpObject != null) {
link = "message.php?all=1&rnd="+randomnumber;
httpObject.open("GET", link , true);
httpObject.onreadystatechange = setAll;
httpObject.send(null);
}
}
function UpdateTimer() {
doReload();
timerID = setTimeout("UpdateTimer()", 5000);
}
function keypressed(e){
if(e.keyCode=='13'){
doWork();
}
}
//-->
</script>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"></head>
<body onLoad="UpdateTimer();">
<div id="main">
<?php
if (!isset($_SESSION['nickname']) ){
createForm();
} else {
$name = isset($_POST['name']) ? $_POST['name'] : "Unnamed";
$_SESSION['nickname'] = $name;
?>
<div id="result">
</div>
<div id="sender" onKeyUp="keypressed(event);"> Envia tu mensage:
<input type="text" name="msg" size="30" id="msg" />
<button onClick="doWork();">Enviar</button>
</div>
<?
}
?>
</div>
</body></html>
message.php Código PHP:
<?php session_start();
if (isset($_GET['msg'])){
if (file_exists('msg.html')) {
$f = fopen('msg.html',"a+");
} else {
$f = fopen('msg.html',"w+");
}
$nick = isset($_GET['nick']) ? $_GET['nick'] : "Hidden";
$msg = isset($_GET['msg']) ? htmlspecialchars($_GET['msg']) : ".";
$line = "<p><span class=\"name\">$nick: </span><span class=\"txt\">$msg</span></p>";
echo $line;
fwrite($f,$line);
fclose($f);
}else if (isset($_GET['all'])) {
$data = file('msg.html');
foreach($data as $linea){
echo $linea;
}
}
?>