Development

Just a word of warning when using PHP and Mysql - if you’re trying to make efficient code and not utilizing all sort of frameworks and abstractions, you might be in for a small surprise in a default setting.

Usually is slightly lazy and often use the mysql_fetch_assoc function. It provides each row as an associative array, and is quite convenient to work with. Recently however while optimizing some code, I figured I’d switch to using mysql_fetch_array assuming it should be more efficient. The logic being that mapping hash keys to array values wouldn’t be needed and it should use less memory.

In most web applications there’s a host of functions (or methods if speaking in the object-oriented world). It’s widely recognized, that it’s probably a good idea to name them something, which may suggest the purpose or functionality of what the function is doing, but often developers seem to fail at making a stringent naming convention. Before starting on your next big development adventure, here are a three suggested rules for naming functions.

I’m sorry but sometimes I really don’t get why even seasoned developers doesn’t learn the art of the commit message in version control system. All too often I’ve come across check-ins where the entire commit message just reads “bugfix”, “change”, “oops” or something just as mindless.

The effort of writing a useful message compared to the potential benefit seems to be one the best ratios - but of course the pay-back is usually some time away - too bad. Once you work on the same code for years - or even better inherit code from others, you’ll quickly learn to appreciate anyone who used more than 10 seconds on composing a thoughtful message for the future.

I’ve been developing web applications for some years now, and while I make no claims to being the world greatest developer, I do figure, that I do have some solid experience which may help others

• or at least encourage thoughts and discussion. This is the first in a series of posts, and while it may be from a PHP developers point of view, it may applicable to other programming languages, and maybe even beyond web applications. Here are my four tips on function parameters.

Always have a default value on all parameters

Functions parameters are often used as input to SQL queries, calling webservices or computations. Null or non-existing values often tend to break these things and throws horrible messages to the end-user.

I’ve been refactoring and refactoring some old code, and it’s kind of odd what short-cuts (or even time bombs), you’ll find in code, which apparently wasn’t supposed to live on for years. In a now retired CMS system, we had an issue every new year, when some kind of bug would reset all “schedules” for upcoming stories and content. No-one ever got around to fix it, as the system was soon to be decommissioned - but sadly the bug did survive a few years anyway.

In user interfaces, it’s sometimes the case, that you need to have dropdowns with content dynamically loaded from a database, and sure you can query the database and place the content in the HTML-source as regular markup, but you can also write a few lines of jQuery powered javascript, and provide the data from an ajax-source.

Here’s how to do it.

First make the drop-down and as the single option make a “loading” message - just to let the user know something is happening.

In this mordern web 2.0 age, javascript includes are used more and more - and in some cases solutions often depend on included content from 3rd parties. While it is nice these 3rd parties may provide us with data (such as the latest tweets from twitter), it would be quite nice, if issues on their server didn’t break the fancy page we’re building.

So the question is this: If you build a page and include javascript from foreign scripts, will error messages on their part break your site? We’ve made the assumption, that the Web2.0 page will degrade gracefully, so that the content/functionality of the javascript-includes is just extra frosting, not needed to use the page

Like tables, jQuery also allows you to play around with all other tags. In a recent project, we wanted to change a fixed set of labels/texts into icons instead. For this challenge jQuery was used to build the new image tag, and for good measure, here is a small example of how you can build an image tag - including alt-text and click-event.

The basic code for building and inserting an image into the DOM looks like this:

I’ve been playing with jQuery the recent weeks, and while it is reasonable simple to get started with and the jQuery documentation is pretty good, I thought I’d share a few snippets of jquery examples/code, which showcases a few simple practical uses for jquery.

First up - tables and jquery.

With jQuery you can add content to a HTML table. Here are to simple examples on how to add content into a table.

Quite awhile ago I posted a little piece of javascript, which could be used to a (very) simple webpage slide show. Someone requested a version a little more advanced for use in a kiosk mode, and sure why not - updating the script with the option to set different times on the webpages displayed was a minor change, and it’s been done now.

If you’d like an updated version of a basic webpage slideshow with an option to specify the time each page is displayed, go ahead get it from the lab.