express随记01

系统变量的设置

app.get(env) | process.env.NODE_ENV: 会自动判断当前环境类型;
app.get(port) | process.env.PORT: 必须手动设置;

`app.param([name], callback)`

用来处理多个匹配

app.param('id', function (req, res, next, id) {

  console.log('CALLED ONLY ONCE');

  next();

})

app.get('/user/:id', function (req, res, next) {

  console.log('although this matches');

  next();

});

app.get('/user/:id', function (req, res) {

  console.log('and this matches too');

  res.end();

});

cookie

其默认值: { path: '/', httpOnly: true, secure: false, maxAge: null }

//注意获取和设置的不同

app.get('/', function (req, res) {

   if (!req.cookies.counter)

    res.cookie('counter', 0);

  else

    res.cookie('counter', parseInt(req.cookies.counter,10) + 1);

  res.status(200).send('cookies are: ', req.cookies);

})

签名加密的cookie

//会自动加密解密处理

app.use(cookieParser('test-sign'));

.........

app.get('/', function (req, res) {

  if (!req.signedCookies.counter)

    res.cookie('counter', 0, {signed: true});

  else

    res.cookie('counter', parseInt(req.signedCookies.counter,10) + 1, {signed: true});

  res.status(200).send('cookies are: ', req.signedCookies);

})

session

//将session保存到redis中

var cookieParser = require('cookie-parser');

var session = require('express-session');

var RedisStore = require('connect-redis')(session);

app.use(cookieParser());

app.use(session({

  resave: true,                             //是否强制保存session。即使没有被修改;

  saveUninitialized: true,             //是否强制保存不是初始化的session;

  name: 'connect.sid',                 //默认浏览器cookie保存的名称;

  store: new RedisStore({

    host: 'localhost',

    port: 6379

  }),

  secret: '0FFD9D8D-78F1-4A30-9A4E-0940ADE81645',

  cookie: { path: '/', maxAge: 3600000 }

}));

app.get('/', function(req, res){

  console.log('Session ID: ', req.sessionID)

  if (req.session.counter) {

    req.session.counter = req.session.counter +1;

  } else {

    req.session.counter = 1;

  }

  res.send('Counter: ' + req.session.counter)

});

其中要控制的实效包括:ttl:session字段保存在数据库的实效;maxAge:cookie字段的有效时间;
如果设置cookie secure: true,那其只会在https时session才会去判断cookie值;
session默认是httpOnly:true
一般要将saveUninitialized 设为false,避免未对session修改也被保存下来;
express-session自带debug模式，运行时设置DEBUG=express-session开启;
一般流程

//登陆

login: fetching->no-session-found->[set]->saveing->split response->set-cookie

         [redirect]-> fetching->session-found->touching->split response->touched

//重新打开

reopen: fetching->session-found->touching->touched

//退出

logout:  fetching->session-found->[set]->no-session->

             [redirect]->fetching->no-session-found

全局参数

//两种形式

app.locals = {};

res.locals = {};

特殊的输出

设置头部

app.get('/set-csv', function(req, res) {

  var body = 'title, tags\n' +

    'Practical Node.js, node.js express.js\n' +

    'Rapid Prototyping with JS, backbone.js node.js mongodb\n' +

    'JavaScript: The Good Parts, javascript\n'

  res.set({'Content-Type': 'text/csv',

    'Content-Length': body.length,

    'Set-Cookie': ['type=reader', 'language=javascript']});

  res.end(body);

});

设置响应码

res.status(200).end();

res.status(200).send();

res.status(200).json();

数据流输出文件

app.get('/stream2', function(req, res) {

  var stream = fs.createReadStream(largeImagePath);

  stream.on('data', function(data) {

    res.write(data);

  });

  stream.on('end', function() {

    res.end();

  });

});

app.get('/stream1', function(req, res) {

  var stream = fs.createReadStream(largeImagePath);

  stream.pipe(res);

});

服务器开关



var server = http.createServer(app);

var boot = function () {

  server.listen(app.get('port'), function(){

    console.info('Express server listening on port ' + app.get('port'));

}); };

var shutdown = function() {

  server.close();

};

if (require.main === module) {

  boot();

} else {

  console.info('Running app as a module');

  exports.boot = boot;

  exports.shutdown = shutdown;

  exports.port = app.get('port');

}

巴特西

express随记01

系统变量的设置

`app.param([name], callback)`

cookie

session

全局参数

特殊的输出

服务器开关

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