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POUnderstanding callbacks in Javascript and node.js
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copied!<p>I'm a long time PHP (CodeIgniter & WordPress) developer that only recently wanted to learn a few other languages. I've set out to learn Ruby (on Rails, and Sinatra), Python (w/ Flask framework) and Javascript with node.js. </p> <p>I decided to create the most basic application I can think of, a URL expander, using each of these languages. I have managed to create a working version in every language, except node.js and Javascript. </p> <p>I kinda know my problem, I know it is related to callbacks. I know I'm not doing it right. I get the basic idea of callbacks, but I just cannot figure out how to fix this mess I have created.</p> <p>This is my <a href="https://gist.github.com/1493486" rel="nofollow">whole code</a>:</p> <pre class="lang-js prettyprint-override"><code>var http = require('http'); var url = require('url'); function expand() { var short = url.parse('http://t.co/wbDrgquZ'); var options = { host: short.hostname, port: 80, path: short.pathname }; function longURL(response) { console.log(response.headers.location); } http.get(options, longURL); } function start() { function onRequest(request, response) { console.log("Request received."); response.writeHead(200, { "Content-Type": "text/plain" }); response.write("Hello World"); expand(); response.end(); } http.createServer(onRequest).listen(8888); console.log("Server has started."); } start(); </code></pre> <p>The server starts, and when a request is made, it calls the expand function which returns the expanded URL in the terminal. I'm trying to get it to print in the browser.</p> <p>Any help is appreciated. Thanks in advance.</p>

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