[Node. js learning] -- (4) -- Express4.x framework, node. js plugin

[Node. js learning] -- (4) -- Express4.x framework, node. js plugin

Express is a standard Nodejs web development framework.

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

Install the project Builder

First install npminstall-g express

Install npm install-gexpress-generator # global install-g

Check the installation result express-V # Check the express version

Uninstall (used when 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

 

Go to the project directory, download the dependent library, and build the project.

Cd nodejs-demo & npm install

Start the project

Npm start

Results:

Directory structure description

Nodejs-demo/

── App. js core configuration file

── Bin startup project script file

├ ── Node_modules project dependency Library

── Package. json project dependency configuration and developer information

├ ── Public static files (css, js, img)

── Routes Routing File (C, controller in MVC)

└ ── Views page file (Ejs template)

Package. json

The scripts attribute is used to define operation commands, which can be easily added. For example, the default start command, npm start is used to execute node./bin/www commands.

App. js File

// Load the dependent library. The original class libraries are encapsulated in connect. Now you need to attach them separately.

Varexpress = require ('express ');

Varpath = require ('path ');

Varfavicon = require ('serve-favicon ');

Varlogger = require ('Morgan ');

VarcookieParser = require ('cookie-parser ');

VarbodyParser = require ('body-parser ');

 

// Load route control

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

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

 

// Create a project instance

Varapp = express ();

 

// Defines the location of the EJS template engine and template file. You can also use jade or other model engines.

App. set ('view', path. join (_ dirname, 'view '));

App. set ('viewengine ', 'ejs ');

 

// Define the icon

App. use (favicon (_ dirname + '/public/favicon. ico '));

// Define the log and output level

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

// Define the data parser

App. use (bodyParser. json ());

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

// Define the cookie parser

App. use (cookieParser ());

// Define the static file directory

App. use (express. static (path. join (_ dirname, 'public ')));

 

// Match the path and route

App. use ('/', routes );

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

 

// 404 handle the error

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 tracking

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 used to separate the configuration and start the program.

View the./bin/www file.

 

#! /Usr/bin/envnode

 

/**

* Dependency Loading

*/

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

Vardebug = require ('debug') ('nodejs-demo: Server ');

Varhttp = require ('http ');

 

/**

* Define the startup Port

*/

Varport = normalizePort (process. env. PORT | '123 ');

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 standardization Functions

*/

FunctionnormalizePort (val ){

Var port = parseInt (val, 10 );

If (isNaN (port )){

Return val;

}

If (port> = 0 ){

Return port;

}

Return false;

}

 

/**

* HTTP exception event processing function

*/

FunctiononError (error ){

If (error. syscall! = 'Listen '){

Throw error;

}

 

Var bind = typeof port === 'string'

? 'Pipele' + port

: 'Port' + Port

 

// Handle specific listen errors withfriendly messages

Switch (error. code ){

Case 'eaccesses ':

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

Process. exit (1 );

Break;

Case 'addrinuse ':

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'

? 'Pipele' + addr

: 'Port' + addr. port;

Debug ('listening on' + bind );

}

Reference

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