var app = require('http').createServer(handler)
, io = require('socket.io').listen(app)
, fs = require('fs');
app.listen(8124);
function handler (req, res) {
fs.readFile(__dirname + '/chat.html', function (err, data) {
if (err) { res.writeHead(500);
return res.end('Error loading chat.html');
}
res.writeHead(200);
res.end(data); });
}
io.sockets.on('connection', function (socket) {
socket.on('addme',function(jsonMessage) {
socket.username = jsonMessage.name;
var toClient = { sender : "SERVER", message : "Good to see your "+ jsonMessage.name};
socket.emit('chat', toClient);
toClient.message = jsonMessage.name + " is on the Desk";
socket.broadcast.emit('chat', toClient);
});
socket.on('sendchat', function(data) {
io.sockets.emit('chat', { sender : socket.username, message : data.message});
});
socket.on('disconnect', function() {
var bye = { sender : "SERVER", message : socket.username+"has left the building"};
io.sockets.emit('chat', bye);
});
});
所有的訊息資料的傳遞都用 JSON 格式，和之前不一樣的地方特別提出來說明一下。先看 addme 這個事件socket.on('addme',function(jsonMessage) {
socket.username = jsonMessage.name;
var toClient = { sender : "SERVER", message : "Good to see your "+ jsonMessage.name};
socket.emit('chat', toClient);
toClient.message = jsonMessage.name + " is on the Desk";
socket.broadcast.emit('chat', toClient);
});再來看到 sendchat 事件
socket.on('sendchat', function(data) {
io.sockets.emit('chat', { sender : socket.username, message : data.message});
});socket.on('disconnect', function() {
var bye = { sender : "SERVER", message : socket.username+"has left the building"};
io.sockets.emit('chat', bye);
});
<html lang="en">
<head>
<meta charset="utf-8">
<title>Chat Room</title>
<script src="http://localhost:8124/socket.io/socket.io.js"></script>
<script>
var socket = io.connect('http://localhost:8124');
socket.on('connect', function() {
socket.emit('addme',{name : prompt('Who are you?')});
});
socket.on('chat',function(data) {
var p = document.createElement('p');
p.innerHTML = data.sender + ': ' + data.message;
document.getElementById('output').appendChild(p);
});
window.addEventListener('load',function() {
document.getElementById('sendtext').addEventListener('click',function() {
var text = document.getElementById('data').value;
socket.emit('sendchat', {message : "say "+text});
}, false);
}, false);
</script>
</head>
<body>
<div id="output"></div> <div id="send">
<input type="text" id="data" size="100" /><br />
<input type="button" id="sendtext" value="Send Text" /> </div>
</body> </html>
socket.on('connect', function() {
socket.emit('addme',{name : prompt('Who are you?')});
});socket.on('chat',function(data) {
var p = document.createElement('p');
p.innerHTML = data.sender + ': ' + data.message;
document.getElementById('output').appendChild(p);
}); document.getElementById('sendtext').addEventListener('click',function() {
var text = document.getElementById('data').value;
socket.emit('sendchat', {message : "say "+text});
}, false);接下來就是 iOS Client 的部分了，首先下載這兩個 Proejct，socket.io-objc 和 SocketRocket 下載完了，先來開啟一個 Single View 的 Project，命名為 ChatClient
接著我們要為 ChatClient 新增一些 Framework，這些是 SocketRocket 必要的，所以要先新增，如下陳列。
- libicucore.dylib
- CFNetwork.framework
- Security.framework
- Foundation.framework
下方的 Send UIButton 則和名為 sendText: 的 UIAction 連結。如下
#import <UIKit/UIKit.h>
#import "SocketIO.h"
@interface CCViewController : UIViewController<SocketIODelegate>
@property (weak, nonatomic) IBOutlet UITextField *inputTextField;
@property (weak, nonatomic) IBOutlet UITextView *resultTextView;
@end
我們 import SockeIO.h 和採用 SocketIODelegate 這個 protocol
接下來準備兩個 ivar，寫在 CCViewController.m 如下
#import "CCViewController.h"
@interface CCViewController (){
NSMutableString * resultString;
SocketIO *socketIO;
}
@end
其中 resultString 是用在保存從 server 來的訊息，而 socketIO 是主要的變數用來和 server 溝通。接下來就是初始化這兩個物件，如下我們寫在 CCViewController.m 的 viewDidLoad 如下
- (void)viewDidLoad
{
[super viewDidLoad];
socketIO = [[SocketIO alloc] initWithDelegate:self];
resultString = [[NSMutableString alloc] initWithCapacity:10];
// Do any additional setup after loading the view, typically from a nib.
}
主要就是 socketIO 初始化就把 delegate 物件設定好。socketIO 在這個例子會用到的 delegate method 如下列出。
- (void) socketIO:(SocketIO *)socket didReceiveEvent:(SocketIOPacket *)packet;
- (void) socketIODidConnect:(SocketIO *)socket;
- (void) socketIODidDisconnect:(SocketIO *)socket;
之後我們會用到。
接著就是第一個動作，筆者寫在 login: 這個 method，按下之後先跳出一個 UIAlertView 讓使用者輸入名稱，然後按下確定後，才真正傳訊息給 server，如下表示
- (IBAction)login:(id)sender {
UIAlertView * nameAlert = [[UIAlertView alloc] initWithTitle:@"Welcome to ChatRoom"
message:@"Who are you" delegate:self cancelButtonTitle:nil
otherButtonTitles:@"OK", nil];
nameAlert.alertViewStyle = UIAlertViewStylePlainTextInput;
[nameAlert show];
}
-(void) alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex{
NSString * inputName = [alertView textFieldAtIndex:0].text;
[socketIO connectToHost:@"localhost" onPort:8124];
NSDictionary * hello = [NSDictionary dictionaryWithObjectsAndKeys:inputName,@"name", nil];
[socketIO sendEvent:@"addme" withData:hello ];
}
這個 UIAlertView 是一個 UIAlertViewStylePlainTextInput，當使用者按下 Alert View 的確定後，會先 connect 到 server, 再準備一個 hello dictionary 當資料，key 為 name，然後用 sendEvent:withData 把 event 名稱寫成 addme 再把 hello 傳給 server。然後我們準備接收從 server 來的訊息需要 implement delegate method。如下
-(void) updateResult{
resultTextView.text = resultString;
}
#pragma SocketIO Delegate
- (void) socketIO:(SocketIO *)socket didReceiveEvent:(SocketIOPacket *)packet{
if ([packet.name isEqualToString:@"chat"]) {
NSDictionary * stringData = (NSDictionary *) [NSJSONSerialization JSONObjectWithData:
[packet.data dataUsingEncoding:NSUTF8StringEncoding] options:
NSJSONWritingPrettyPrinted error:NULL];
NSDictionary * messageData = [[stringData objectForKey:@"args"] objectAtIndex:0];
[resultString appendFormat:@"%@ say %@\n",
[messageData objectForKey:@"sender"],[messageData objectForKey:@"message" ]] ;
}
[self updateResult];
}
我們必需要 implement socketIO:didReceiveEvent: 才會收到 server 來的資料，在這個 method 裡，先用 data.name 來得知 event 的名稱，再判斷是不是 chat，
由 packet.data 包起來的訊息有點複雜我們來看其原本的樣子。如下
{"name":"chat","args":[{"sender":"SERVER","message":"Good to see your iOS"}]}
NSDictionary * stringData = (NSDictionary *) [NSJSONSerialization JSONObjectWithData:
[packet.data dataUsingEncoding:NSUTF8StringEncoding] options:
NSJSONWritingPrettyPrinted error:NULL]; NSDictionary * messageData = [[stringData objectForKey:@"args"] objectAtIndex:0];
[resultString appendFormat:@"%@ say %@\n",
[messageData objectForKey:@"sender"],[messageData objectForKey:@"message" ]] ;如此一來就可以先打開 server ，用 node chatServer.js 執行後，就可以執行 iOS ，正常的情況下就會出現如下畫面。
先輸入名稱
看到 Server 來的訊息
- (IBAction)sendText:(id)sender {
NSDictionary * chat = [NSDictionary dictionaryWithObjectsAndKeys:inputTextField.text,@"message", nil];
[socketIO sendEvent:@"sendchat" withData:chat];
[inputTextField resignFirstResponder];
}
- (void) socketIODidConnect:(SocketIO *)socket{
NSLog(@"did connect to %@", socket);
}
- (void) socketIODidDisconnect:(SocketIO *)socket{
NSLog(@"did disconnect to %@", socket);
}
