Javascript

Today’s post is a quick tip on how to easily create a sleep-delay loop in JavaScript. ...

We often think about best practices while developing software. Sometimes it is also instructive to contemplate what not to do when writing software. Today’s post covers some logic in AngularJS services which should be avoided save for rare exceptions. ...

Networks are unreliable. Put more precisely, TCP networking can experience many different types of failures with resulting loss of connectivity. Do not let the linked post’s title fool you, it goes on to list a number of real-world computer networking failures. HTTP is a great way to communicate over the public internet, where failures may occur at any time, because the protocol itself is stateless and does not rely on a persistent connection. HTML5 WebSockets, however, do use a persistent TCP connection. A connection that can cut or closed without warning. Today’s post is a short commentary on adding error handlers and heartbeat messaging to WebSocket clients and servers. ...

Performance counters can be implemented in applications to help operators determine where bottlenecks are in the design. Microsoft has a decent page, that’s somewhat Windows centric, about performance counters. This post is about implementing the most basic type of counter, a value which monotonically increases, in JavaScript for NodeJS and the performance implications of different designs. ...

Note I didn’t say always should export objects, but for the sanity of everyone involved, in many cases a required module should return a constructor and not a fully instantiated object. Today’s post is about why your NodeJS modules should look like this: /** * @constructor */ function myConstructor(someDependency) { /* setup my object here */ } module.exports = myConstructor; and not this: var myObj = { myService: new MyService() }; myObj.myFunction = function(foo) { /* do stuff with foo here */ }; module.exports = myObj; ...

I’ve written before about how it’s better to write straightforward code than trying to be clever and pre-optimize. Another example of where this rule is true is the cost of iteration between different styles of array loops in JavaScript when executed within NodeJS. ...

Operator precedence determines the order [Operator precedence determines the order]2 and binary operators are executed. In many situations, knowing basic mathematical operator precedence (for +,-,*, etc) is enough. In other situations not knowing the specifics of language can lead to hard to find errors. Quickly, in JavaScript what does 'the boogeyman ' + false ? 'is scary' : 'is not scary' evaluate to? ...

Recently I started writing a new web application which uses OData V4 as the protocol for passing data to back and forth between the JavaScript client and ASP.Net server. The client is written using AngularJS which doesn’t have any built-in facilities for working in OData APIs. In order to avoid writing my own OData message handler I used the Apache Olingo library to handle the grunt work of sending requests and receiving responses. I wanted to encapsulate the Olingo library in an AngularJS service in order to make using it easier, the following post details how this was done. ...

Previously we have discussed one approach and gave some implementing code for providing time zone adjusted date times to client web applications. Within the space of user facing web applications there are few different approaches to handling the storage and transmission of date time information. Today we will look at a couple broader themes for delivery of date times to client applications from servers and some thoughts on how to do it well. ...

This is short post about a couple issues that end users might run into when using a method of displaying dates I described in a prior post. In short, Microsoft Internet Explorer 9 cannot parse certain types of ISO8601 dates correctly and Google Chrome does not track the system’s time zone correctly. ...