"Node. JS Learning"--(4)--express4.x framework

Express is the NODEJS standard Web development Framework

Reference http://blog.fens.me/nodejs-express4/

Install the Project Builder

Install Npminstall-g Express First

Re-install NPM install-gexpress-generator #全局安装-G

Check the installation results express-v# Check the version of Express

Uninstall (use if needed)

NPM Uninstall-g Express

Reference

http://blog.csdn.net/JBBOY/article/details/25038299

Http://jingyan.baidu.com/album/922554468a3466851648f419.html?picindex=1

Create a project

Express-enodejs-demo

Enter the project directory, download the dependent library, build the project.

CD Nodejs-demo && NPM Install

Start Project

NPM start

Effects such as

Directory Structure Description

nodejs-demo/

├──app.js Application Core configuration file

├──bin script files for startup projects

├──node_modules Project Dependency Library

├──package.json Project Dependency Configuration and developer information

├──public static file (css,js,img)

├──routes Routing file (C,controller in MVC)

└──views page file (ejs template)

Package.json

Where the Scripts property is used to define the operation command, it is very convenient to add the start command, such as the default start, and the NPM start to represent the node./bin/www command.

App.js file

Load Dependent Library, originally this class library is encapsulated in Connect, now need to note load separately

Varexpress = require (' Express ');

Varpath = require (' path ');

Varfavicon = require (' Serve-favicon ');

Varlogger = require (' Morgan ');

Varcookieparser = require (' Cookie-parser ');

Varbodyparser = require (' Body-parser ');

Load Routing Control

Varroutes = require ('./routes/index ');

Varusers = require ('./routes/users ');

Create a Project instance

Varapp = Express ();

Define the Ejs template engine and template file location, or you can use Jade or another model engine

App.set (' Views ', Path.join (__dirname, ' views '));

App.set (' Viewengine ', ' Ejs ');

Defining icon Icons

App.use (Favicon (__dirname+ '/public/favicon.ico '));

Defining logs and output levels

App.use (Logger (' dev '));

Defining Data parsers

App.use (Bodyparser.json ());

App.use (bodyparser.urlencoded ({extended:false}));

Defining a Cookie Parser

App.use (Cookieparser ());

Define a static file directory

App.use (Express.static (Path.join (__dirname, ' public '));

Matching paths and routes

App.use ('/', routes);

App.use ('/users ', users);

404 Error handling

App.use (function (Req,res, next) {

var err = new Error (' not Found ');

Err.status = 404;

Next (ERR);

});

Development environment, 500 error handling and error stack tracing

if (App.get (' env ') = = = ' Development ') {

App.use (function (err, req, res, next) {

Res.status (Err.status | | 500);

Res.render (' Error ', {

Message:err.message,

Error:err

});

});

}

Production environment, 500 error handling

App.use (function (Err,req, res, next) {

Res.status (Err.status | | 500);

Res.render (' Error ', {

Message:err.message,

Error: {}

});

});

Output Model App

module.exports= app;

www file

The www file is also a node script that separates configuration and startup programs.

View the./bin/www file.

#!/usr/bin/envnode

/**

* Dependent loading

*/

Varapp = require ('.. /app ');

Vardebug = require (' Debug ') (' nodejs-demo:server ');

Varhttp = require (' http ');

/**

* Define the boot port

*/

Varport = Normalizeport (Process.env.PORT | | ' 3000 ');

App.set (' Port ', port);

/**

* Create an HTTP server instance

*/

Varserver = Http.createserver (APP);

/**

* Start the Network Service listening port

*/

Server.listen (port);

Server.on (' Error ', onError);

Server.on (' Listening ', onlistening);

/**

* Port Normalization function

*/

Functionnormalizeport (val) {

var port = parseint (val, 10);

if (IsNaN (port)) {

return Val;

}

if (port >= 0) {

return port;

}

return false;

}

/**

* HTTP Exception event handler function

*/

Functiononerror (Error) {

if (Error.syscall!== ' listen ') {

Throw error;

}

var bind = typeof Port = = = ' String '

? ' Pipe ' + port

: ' Port ' + port

Handle specific Listen errors withfriendly messages

Switch (error.code) {

Case ' eacces ':

Console.error (bind + ' requires elevatedprivileges ');

Process.exit (1);

Break

Case ' Eaddrinuse ':

Console.error (Bind + ' is already inuse ');

Process.exit (1);

Break

Default

Throw error;

}

}

/**

* Event Binding function

*/

Functiononlistening () {

var addr = server.address ();

var bind = typeof Addr = = = ' String '

? ' Pipe ' + addr

: ' Port ' + addr.port;

Debug (' Listening on ' + bind);

}

Reference

http://blog.fens.me/nodejs-express4/

Node. JS Learning--(4)--express4.x framework