Callbacks are a systemic part of a Node.js application. A non-blocking well-balanced flow of controlled asynchronous modules is made possible by properly implemented callbacks. But what is “properly implemented”? Creating code that will scale with your projects means using a reliable protocol that is a well-known standard. The “error-first” callback (also known as an “error-back”,… Read more Error First Callbacks in Node JS
Example of how to iterate an array with a promise It can be challenging to figure out how to iterate over an array of items with a promise. The following code takes a callback function that may or may not be a promise already. Once inside the PromiseForEach function, the callback will become a promise… Read more Iterate an array with a promise in javascript
If you are developing a node js application using devtool, you may experience a rather frustrating situation whereby you application stops without any traceable errors followed by a subsequent reload of the devtool. Why does devtool keep reloading when there are no errors? There is a likelyhood that you are experiencing this issue as you… Read more [solved] devtool reloads if application writes to a file
A simple way to ensure that the forever module restarts your app, at least on ubuntu 14, is to use the @reboot option in cron. Edit cron with crontab -e It is a good idea to get familiar with how to use cron. But this post is a cut-to-the-chase here’s how to do it explanation, so… Read more Auto Restart Forever (NodeJS) on Ubuntu 14
While working with NodeJS on an AWS Ubuntu 14 box, I got the following error: /usr/bin/env: node: No such file or directory On some Linux distributions, AWS in my case, there is a namespace issue which causes errors at times. The error is a result of some distributions installing NodeJS with the name nodejs as opposed to node. The… Read more SOLVED: /usr/bin/env: node: No such file or directory
EADDRINUSE indicates the port number that listen() is attempting to bind the server to is already in use. Sometimes, even though you have hit Control C a few times. Somehow nodejs is still running. My guess is that there are lingering processes from a faulty termination for whatever reason. How to fix Error: listen EADDRINUSE… Read more Error: listen EADDRINUSE with NodeJS Server
Port 80 Redirect port 80 to port 3000 with this command: sudo iptables -t nat -A PREROUTING -i eth0 -p tcp –dport 80 -j REDIRECT –to-port 3000 Then launch the Node.js application on port 3000. Now requests to port 80 will map to the nodejs application on port 3000. Edit the /etc/rc.local file and adding… Read more How to setup Node.js application server with port 80
The npm web server is a very simple web server used in development and testing for delivering static files. While attempting to use start the npm web server you may see an error like this: at exports._errnoException (util.js:746:11) at Server._listen2 (net.js:1156:14) at listen (net.js:1182:10) at net.js:1280:9 at dns.js:85:18 at process._tickCallback (node.js:355:11) at Function.Module.runMain (module.js:503:11) at startup… Read more Error: listen EADDRINUSE
While setting up a grunt.js file, I ran into the following stubborn error. Running “sass:dist” (sass) task Errno::ENOENT: No such file or directory @ rb_sysopen – undefined Use –trace for backtrace. After having Googled several solutions to the problem. I ended up updating my Ruby and uninstalling and re-installing nodejs among other things. It turns… Read more How To Fix: “Errno::ENOENT: No such file or directory @ rb_sysopen – undefined” Grunt Error