Node.js Introduction

A brief introduction to Node.js given at the Grand Rapids Web Development Group.

Transcript

1. INTRODUCTION
   

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2. Hi, I’m
   @bkeepers
   

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4. nodejs.org
   Node.js is a platform built on Chrome's
   JavaScript runtime for easily building
   fast, scalable network applications.
   Node.js uses an event-driven, non-
   blocking I/O model that makes it
   lightweight and efficient, perfect for
   data-intensive real-time applications
   that run across distributed devices.
   

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5. server side
   JavaScript
   

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6. $ node webserver.js
   var http = require('http'),
   server = http.createServer();
   server.on('request', function (req, res) {
   res.writeHead(200, {'Content-Type': 'text/plain'});
   res.end('Hello World\n');
   });
   server.listen(1337, "127.0.0.1");
   console.log('Server running at http://127.0.0.1:1337/');
   webserver.js
   

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8. event loop
   modules
   package
   management
   

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9. non-blocking
   evented I/O
   

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10. event driven
    

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11. event driven
    Button
    

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12. event driven
    Button
    

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13. event driven
    Button
    $('button').on('click', function(event) {
    alert('Event Driven!')
    });
    

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14. event driven
    server.on('request', function(req, res) {
    res.write(handleRequest(req))
    });
    

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15. non-blocking
    

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17. // blocking
    var files = fs.readdirSync('/tmp')
    for(var i = 0; i < files.length; i++) {
    var file = files[i];
    fs.unlinkSync('/tmp/' + file);
    console.log('successfully deleted ' + file);
    }
    

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18. // blocking
    var files = fs.readdirSync('/tmp')
    for(var i = 0; i < files.length; i++) {
    var file = files[i];
    fs.unlinkSync('/tmp/' + file);
    console.log('successfully deleted ' + file);
    }
    // non-blocking
    fs.readdir('/tmp', function(err, files) {
    for(var i = 0; i < files.length; i++) {
    var file = files[i];
    fs.unlink('/tmp/' + file, function (err) {
    if (err) throw err;
    console.log('successfully deleted ' + file);
    });
    }
    });
    

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19. CommonJS
    modules
    

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20. JavaScript
    Pollutes
    

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21. JavaScript
    Pollutes
    string = "pollution";
    

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23. var http = require('http');
    

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24. hello.js
    module.exports = function() {
    return 'Hello World'
    };
    

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25. $ node myapp.js
    myapp.js
    var hello = require('./hello.js');
    console.log(hello());
    

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26. package
    management
    

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27. npmjs.org
    

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28. $ npm install
    

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29. package.json
    

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30. package.json
    $ npm install
    {
    "name": "myapp",
    "version": "0.0.1",
    "dependencies": {
    "socket.io": "0.8.7",
    "coffee-script": "1.2.0",
    "spine": "~1.0.5"
    }
    }
    

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31. building the simplest
    chat app in the world
    demo
    

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32. references
    

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33. http://nodejs.org/api/
    

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35. thanks!
    @bkeepers
    

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