一共只需要兩個文件，一個index.html,一個backend.php.github上的別人的項目，先留下來備用。
<!DOCTYPE html>
<!--[if lt IE 7]> <html class="no-js lt-ie9 lt-ie8 lt-ie7"> <![endif]-->
<!--[if IE 7]> <html class="no-js lt-ie9 lt-ie8 ie7"> <![endif]-->
<!--[if IE 8]> <html class="no-js lt-ie9 ie8"> <![endif]-->
<!--[if gt IE 8]><!-->
<html class="no-js" xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en"> <!--<![endif]-->
<head>
<meta charset="utf-8" />
<title>php+js長輪詢實時聊天</title>
<style>
/*<![CDATA[*/
body {
font: 14px Arial, Sans-serif;
}
.js .error {
display: none;
}
.no-js .error {
border: 1px solid red;
background: pink;
margin: 5px;
padding: 5px;
}
#connection {
display: inline-block;
width: 100px;
}
.lt-ie8 #connection {
zoom: 1;
}
#content {
border-left: 4px solid silver;
padding: 0 5px;
margin: 20px 0;
}
p {
margin: 5px;
}
#note {
font-weight: bold;
}
p span {
margin: 0 5px 0 0;
}
p.new {
font-weight: bold;
color: green;
}
form {
display: block;
}
#message {
width: 350px;
}
/*]]>*/
</style>
<script>
//<![CDATA[
"use strict";
if (top.location !== self.location) {
top.location = self.location.href;
}
(function (html) {
html.className = html.className.replace(/\bno-js\b/, "js");
})(document.documentElement);
//]]>
</script>
</head>
<body>
<p class="error">需要js支持</p>
<h1>php+js長輪詢實時聊天</h1>
<p class="info"><span>連接</span><strong id="connection">連接中...</strong><span>Current Status:</span><strong id="status">無刷新</strong></p>
<div id="content">
<p id="note">真實聊天~</p>
</div>
<form id="form">
<label for="message">Message:</label>
<input type="text" id="message" value="" />
<input type="submit" id="button" value="Send" />
</form>
<script>
//<![CDATA[
"use strict";
// shorthand
function $(id) {
return document.getElementById(id);
}
// element.hasOwnProperty won't work in IE6/7/8
function hasOwnProperty(target, property) {
return Object.prototype.hasOwnProperty.call(target, property);
}
// determine whether the specified object is an instance of Array
function isArray(obj) {
if (Array.isArray) {
isArray = function (obj) {
return Array.isArray(obj);
};
} else {
isArray = function (obj) {
return Object.prototype.toString.call(obj) === "[object Array]";
};
}
return isArray(obj);
}
// get current date and time
function getCurrentDatetime() {
var pad = function (n) {
return n < 10 ? '0' + n : n;
},
date = new Date();
return date.getFullYear() + '-' + pad(date.getMonth() + 1) + '-' + pad(date.getDate()) + ' ' + pad(date.getHours()) + ':' + pad(date.getMinutes()) + ':' + pad(date.getSeconds());
}
// create an xhr
function createXHR () {
if (XMLHttpRequest !== undefined) {
createXHR = function () {
return new XMLHttpRequest();
};
} else if (ActiveXObject !== undefined) {
var versions = ["MSXML2.XMLHttp.6.0", "MSXML2.XMLHttp.3.0", "MSXML2.XMLHttp"],
i, activeXString;
for (i = 0; i < versions.length; i++) {
try {
new ActiveXObject(versions[i]);
activeXString = versions[i];
} catch (e) {
// skip
}
}
createXHR = function () {
return new ActiveXObject(activeXString);
};
} else {
createXHR = function () {
throw new Error("No XMLHttpRequest object available.");
};
}
return createXHR();
}
// convert an object to http parameter string
function serialize(data) {
var params = [], key, value, i;
for (key in data) {
if (data.hasOwnProperty(key)) {
value = data[key];
if (isArray(value)) {
for (i = 0; i < value.length; i++) {
params.push(encodeURIComponent(key) + '=' + encodeURIComponent(value[i]));
}
} else {
params.push(encodeURIComponent(key) + '=' + encodeURIComponent(value));
}
}
}
return params.join('&').replace(/%20/g, '+'); // replace all '%20'(space) with '+'
}
// make an ajax request
function request(options) {
var _options = {
method: "POST",
url: "",
data: {},
// xhr.readyState === 0, UNSENT
// The object has been constructed.
onUnsent: function (xhr) {},
// xhr.readyState === 1, OPENED
// The open() method has been successfully invoked. During this state request headers can be set using setRequestHeader() and the request can be made using the send() method.
onOpened: function (xhr) {},
// xhr.readyState === 2, HEADERS_RECEIVED
// All redirects (if any) have been followed and all HTTP headers of the final response have been received. Several response members of the object are now available.
onSent: function (xhr) {},
// xhr.readyState === 3, LOADING
// The response entity body is being received.
onReceiving: function (xhr) {},
// xhr.readyState === 4, DONE
// The data transfer has been completed or something went wrong during the transfer (e.g. infinite redirects).
onComplete: function (xhr) {},
// xhr.readyState === 4 && ((xhr.status >= 200 && xhr.status < 300) || xhr.status === 304)
onSuccess: function (xhr) {},
// !(xhr.readyState === 4 && ((xhr.status >= 200 && xhr.status < 300) || xhr.status === 304))
onFailure: function (xhr) {}
},
xhr = createXHR();
// initializing properties
for (var option in options) {
if (hasOwnProperty(_options, option)) {
_options[option] = options[option];
}
}
// prevent from caching
_options.data.rand = (new Date()).getTime();
xhr.onreadystatechange = function () {
switch (xhr.readyState) {
case 0:
_options.onUnsent(xhr);
break;
case 1:
_options.onOpened(xhr);
break;
case 2:
_options.onSent(xhr);
break;
case 3:
_options.onReceiving(xhr);
break;
case 4:
_options.onComplete(xhr);
if ((xhr.status >= 200 && xhr.status < 300) || xhr.status === 304) {
_options.onSuccess(xhr);
} else {
_options.onFailure(xhr);
}
break;
}
};
if (_options.method === "GET") {
xhr.open(_options.method, _options.url + '?' + serialize(_options.data), true);
} else {
xhr.open(_options.method, _options.url, true);
xhr.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
}
xhr.setRequestHeader("X-Requested-With", "XMLHttpRequest");
xhr.send(_options.method === "GET" ? null : serialize(_options.data));
}
var connection, // current connection
status, // current status
content, // message area
note, // note
message,
button,
form,
timestamp = 0, // determine new message
msg = {
MSG_CAN_NOT_BE_EMPTY: "Message can not be empty.",
SEND: "Send",
SENDING: "Sending...",
SENDING_MSG: "Sending Message...",
MSG_SENT: "Message Sent.",
MSG_RECEIVED: "Message Received.",
NO_ACTIVITY: "No Activity.",
CONNECTING: "Connecting...",
CONNECTED: "Connected."
};
window.onload = function () {
status = $("status");
connection = $("connection");
content = $("content");
note = $("note");
message = $("message");
button = $("button");
form = $("form");
note.innerHTML = "<span>[" + getCurrentDatetime() + "]</span>" + note.innerHTML;
// 點擊發送按鈕
form.onsubmit = function () {
if (/^\s*$/.test(message.value)) {
alert('說啥？');
} else {
button.disabled = true;
button.value = msg.SENDING;
status.innerHTML = msg.SENDING_MSG;
request({
url: "backend.php",
data: {
message: message.value
},
onSuccess: function (xhr) {
status.innerHTML = msg.MSG_SENT;
message.value = "";
button.value = msg.SEND;
button.disabled = false;
setTimeout(function () {
status.innerHTML = msg.NO_ACTIVITY;
}, 3000);
}
});
}
return false;
};
// long polling to retrieve new message in real time
(function connectToServer() {
request({
url: "backend.php",
data: {
timestamp: timestamp
},
onSuccess: function (xhr) {
var p = document.createElement('p');
connection.innerHTML = msg.CONNECTED;
// response should be json string, if not something wrong may happened,
// such as exceeding max execution time, just ignore it and start another request
if (/^\{.*\}$/.test(xhr.responseText)) {
var data = eval('(' + xhr.responseText + ')');
p.innerHTML = "<span>[" + getCurrentDatetime() + "]</span>" + data.message;
p.className = "new";
timestamp = data.timestamp;
content.appendChild(p);
if (status.innerHTML !== msg.MSG_SENT) {
status.innerHTML = msg.MSG_RECEIVED;
setTimeout(function () {
status.innerHTML = msg.NO_ACTIVITY;
}, 3000);
}
setTimeout(function () {
p.className = "";
}, 3000);
}
connectToServer(); // start another long polling request
},
onFailure: function (xhr) {
connection.innerHTML = msg.CONNECTING;
setTimeout(function () {
connectToServer();
}, 5000); // start another long polling request
}
});
})();
};
//]]>
</script>
</body>
</html>
<?php
// display all errors
error_reporting(-1);
ini_set('display_errors', 'On');
// Disable caching of the current document:
header('Cache-Control: no-cache, no-store, max-age=0, must-revalidate');
header('Expires: Mon, 26 Jul 1997 05:00:00 GMT'); // Date in the past
header('Pragma: no-cache');
$filename = dirname(__FILE__) . '/data.txt';
// store new message in the file
$message = isset($_POST['message']) ? $_POST['message'] : '';
if ($message != '') {
file_put_contents($filename, $message);
exit();
}
// infinite loop until the data file is modified
$lastmodif = isset($_POST['timestamp']) ? $_POST['timestamp'] : 0;
$currentmodif = filemtime($filename);
while ($currentmodif <= $lastmodif) { // check if the data file has been modified
usleep(10000); // sleep 10ms to unload the CPU
clearstatcache();
$currentmodif = filemtime($filename);
}
// return a json array
$response = array();
$response['message'] = file_get_contents($filename);
$response['timestamp'] = $currentmodif;
echo json_encode($response);
flush();
