Nodejs
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Node.js is an open-source and cross-platform JavaScript runtime environment built on Chrome's V8 JavaScript engine. It uses an event-driven, non-blocking I/O model that makes it lightweight and efficient for data-intensive real-time applications. Key features include being asynchronous and event-driven, having a large ecosystem of open-source modules, and supporting building scalable network applications like web servers and web sockets. Common uses of Node.js include building servers, real-time applications, IoT applications, and building JavaScript modules to share across the ecosystem.
![Package Manager - npm
● NPM is the package manager for the
Node JavaScript platform
● It puts modules in place so that node
can find them.
● Reads all project dependencies from
package.json
● Main commands are init, install, link, ls,
and search.
{
"name": "NewProject",
"version": "0.0.1",
"description": "showcase project",
"main": "index.js",
"scripts": {
"test": "node index.js"
},
"keywords": [
"new",
"project"
],
"author": "matef",
"license": "BSD-2-Clause"
}](https://image.slidesharecdn.com/nodejs-141124045934-conversion-gate01/85/Nodejs-10-320.jpg)
Nodejs
- 2. Node is ● Open source. ● Cross-platform. ● Event-driven. ● Non-blocking I/O.
- 3. Built on V8 ● JavaScript engine for Chrome. ● written in C++. ● V8 can run standalone, or can be embedded into any C++ application.
- 4. History ● Created for Linux use in 2009. ● By Ryan Dahl ● Sponsored by Joyent.
- 5. Non Blocking IO - Event Loop
- 6. Hello World setTimeout(function(){ console.log('world'); },2000); console.log('Hello'); process.stdin.on('data', function (chunk) { process.stdout.write('data: ' + chunk); }); ● Non-blocking IO needs different mindset and coding style. ● You are organizing your code around events. ● Nobody can tell the exact sequence of execution especially for IO events.
- 7. Callback could be a hell fs.readFile(my.json', function(err, data) { var info = JSON.parse(data); db.findOne({id: info.id}, function(err, record) { fs.writeFile('my.txt', record.title, function(){ console.log('Finish job'); }) }) });
- 8. Http Server var http = require('http'); Import module http.createServer(function (request, response) { Use module response.writeHead(200, {'Content-Type': 'text/plain'}); response.end('Hello Worldn'); }).listen(8124); console.log('Server running at http://127.0.0.1:8124/');
- 9. Create Module exports.test = function(){ console.log("Hi I'm inside the test module"); } ● Use exports object to externalize function, object or class ● User require function to import module into your code. var module = require('./test2.js'); module.test();
- 10. Package Manager - npm ● NPM is the package manager for the Node JavaScript platform ● It puts modules in place so that node can find them. ● Reads all project dependencies from package.json ● Main commands are init, install, link, ls, and search. { "name": "NewProject", "version": "0.0.1", "description": "showcase project", "main": "index.js", "scripts": { "test": "node index.js" }, "keywords": [ "new", "project" ], "author": "matef", "license": "BSD-2-Clause" }
- 11. Frameworks - ExpressJS ● Express is a minimal and flexible Node.js web application framework. ● Express enables developer to organize artifacts and routes and views in a simple way. ● Express has a generator tool that build the typical structure for simple web project.
- 12. IBM® Bluemix™ ● IBM® Bluemix™ is the IBM open cloud platform. ● Bluemix™ supports Nodejs as one of its runtimes. ● Bluemix™ provides boilerplates for faster development start.
- 13. Some insight into Nodejs ...
- 14. It is the next big thing … catch up :)