Complete Node.js Web Server Tutorial with Example
                      
NiFooduer.j Cs oWnesubl Staenrvceyr
 
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Table of Contents
 The Web Server
 The Request Object
 The Response Object
 Routing Requests
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2
What Do the Web Servers Do? (Again)
 All physical servers have hardware
 The hardware is controlled by the operating system
 Web servers are software products that use the operating  system to handle web 
requests
Web servers serve Web content
 These requests are redirected to other software products (ASP.NET, PHP, etc.), 
depending on the web server settings
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3
NodeJS Web Server
 Require the 'http' module
Create server function (createServer)
Request/Response wrapper objects
Listen function (specifies port and IP (host))
Headers are objects (keys are lowercased)
{ 
  'content-length': '123',
  'content-type': 'text/plain',
  'connection': 'keep-alive',
  'accept': '*/*'
}
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NodeJS Web Server
 Basic server implementation
 http://nodejs.org/api/http.html
let http = require('http')
http
  .createServer((req, res) => {
    res.writeHead(200, {
        'Content-Type': 'text/plain'
    }) // return success header
    res.write('My server is running! ^_^') // response
    res.end() // finish processing current request
  })
  .listen(1234);
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The Request Wrapper
 The Request wrapper
http.IncommingMessage class
Implements the Readable Stream interface
 Properties
httpVersion – '1.1' or '1.0'
headers – object for request headers
method – 'GET', 'POST', etc.
url – the URL of the request
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The Response Wrapper
 The Response wrapper
http.ServerResponse class
Implements the Writable Stream interface
 Methods
writeHead(statusCode, [headers])
let body = 'hello world'
res.writeHead(200, {
  'Content-Length': body.length, // not always valid
  'Content-Type': 'text/plain',
  'Set-Cookie': ['type=master', 'language=javascript']
});
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The Response Wrapper
 Methods
write(chunk, [encoding])
end()
 Always call the methods in the following way
writeHead
write
end
res.writeHead('Hello world!') // default encoding: utf8
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Route Requests
 URL Parsing modules
'url' and 'querystring'
both have parse method
let url = require('url')
console.log(url.parse('/status?name=ryan'))
// logs
// { 
//    href: '/status?name=ryan',
//    search: '?name=ryan',
//    query: { name: 'ryan' },
//    pathname: '/status' 
// }
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