Today I was looking for an unobtrusive method of determining a user’s connection speed using JavaScript. A quick search on Google returned an array of tricks mostly having to do with using Ajax to make a call behind the scenes, and track the payload time for the small file. In most cases people use an image with a random variable at the end to avoid caching, like image.jpg?foo=1Rt2X21. This is all good but adds an HTTP connection which could potentially interfere with the user’s experience, especially if they are already on a slow connection to begin with. Continue »

The latest release of the iPhone SDK from Apple comes with an array of new Mac utilities for developing iPhone specific software. One of the new tools included with the iPhone SDK beta is the Aspen Simulator. Aspen is an iPhone simulator that developers can test their apps on which emulates all of the the features and functionality of the iPhone. For example you can use the mouse to swipe the page up, down, even pinch and more. Continue »

Here is a simple test to see if users have Firebug installed on their browsers. Obviously this would also weed out non-FireFox users.

if (window.console && window.console.firebug) {
  alert("found Firebug");
}else{
  alert("can't find Firebug");
}

Continue »

Here is the simple form of an AJAX call made to an XML document, parsing through the returned document and and grabbing the a specific node from the DOM. There is a try/catch clause to handle the 4 different sets of XMLHTTP objects for different browsers. The callback function is called once the response is returned as 4+200 and the response is rendered to the user. Below is the JavasScript code snippet. Continue »

Lines of markup code per website are growing at a hurried pace these days. JavaScript and CSS files are getting bigger by the day. But you want to keep your site lean and speedy and avoid from becoming slow and bloated. There are some basic techniques I use to optimize JavaScript files and the same ideas can be applied to CSS and HTML files as well. I’ll briefly cover 4 popular solutions, namely validating, joining, shrinking and compressing your markup source code. Continue »