Node js调用socket.io函数的用法

在我的nodeClient.js中，我有一个函数

socket.emit( 'message', { name: nameVal, message: msg } );

和

socket.on( 'message', function( data ) {
var actualContent = $( "#messages" ).html();
var newMsgContent = '<li> <strong>' + data.name + '</strong> : ' + data.message + '</li>';
var content = newMsgContent + actualContent;
$( "#messages" ).html( content );
});

这里可以清楚地看到，socket.on（）函数正在使用这里将数据推送到特定的id，中

但是，如果我检查html 中的id

<ul id="messages">
    <?php 
        $query = $pdo->prepare( 'SELECT * FROM message ORDER BY msgid DESC' );
        $query->execute();
        $messages = $query->fetchAll( PDO::FETCH_OBJ );
        foreach( $messages as $message ):
    ?>
            <li> <strong><?php echo $message->name; ?></strong> : <?php echo $message->message; ?> </li>
        <?php endforeach; ?>
</ul>

在html页面中，我们使用mysql查询从数据库中获取数据，这在没有nodejs的php中也很好。。。现在，我的问题是"socket.on（）或socket.emit（）函数是如何帮助获得结果的。"

这是我完整的nodeClient.js文件

var socket = io.connect( 'http://localhost:8080' );
$( "#messageForm" ).submit( function() {
var nameVal = $( "#nameInput" ).val();
var msg = $( "#messageInput" ).val();
//alert(msg);
socket.emit( 'message', { name: nameVal, message: msg } );
// Ajax call for saving datas
$.ajax({
url: "./ajax/insertNewMessage.php",
type: "POST",
data: { name: nameVal, message: msg },
success: function(data) {
}
});
return false;
});
socket.on( 'message', function( data ) {
var actualContent = $( "#messages" ).html();
var newMsgContent = '<li> <strong>' + data.name + '</strong> : ' + data.message + '</li>';
var content = newMsgContent + actualContent;
$( "#messages" ).html( content );
});

这是我的nodeServer.js

var socket = require( 'socket.io' );
var express = require( 'express' );
var http = require( 'http' );
var app = express();
var server = http.createServer( app );
var io = socket.listen( server );
io.sockets.on( 'connection', function( client ) {
    console.log( "New client !" );
    client.on( 'message', function( data ) {
        console.log( 'Message received ' + data.name + ":" + data.message );
        client.broadcast.emit( 'message', { name: data.name, message: data.message } );
        io.sockets.emit( 'message', { name: data.name, message: data.message } );
    });
});
server.listen( 8080 );

任何人都请帮我。提前感谢！