PHP

Getting the first or last item from an array in PHP is usually quite easy. If you create an array and then add a bunch of values to it then the array index will increment by 1 for every element you add. This means that in order to get the first element from an array you just reference the default starting position (0). To get the last item in the array the index key will be the length of the array, minus 1. Here is some example code showing this.

<?php
$array = array();
$array[] = 1;
$array[] = 2;

// get the first item in the array
print $array[0]; // prints 1

// get the last item in the array
print $array[count($array) - 1]; // prints 2

Things become slightly more complicated when the array has non standard key values. Take the following array for example in which the array count it started at 1.

I recently have started looking into making myself a PHP Zend Certified Engineer and after doing a bit of research I found that the standard PHP string and array functions appear to be a large part of the exam material. So as a starting point (and for future revision) I decided it might be a good idea to create a revision sheet for those functions.

The DateTime classes in PHP have been available since version 5.2, but I have largely ignored them until recently. This was partly due to the fact that I was working in PHP 5.1 environments a lot (don't ask) but mostly because I was just used to using the standard date functions that have always been a part of PHP (well, since version 4). I wanted to explain why I will be using the new DateTime classes more from now on and why you shouldn't be hesitant to use them.

Using a combination of strtotime() and date() can handle most things and is a good method to quickly grab a date.

XDebug is a great PHP debugging tool, but it also comes with a very useful profiler that can tell you all sorts of information about your PHP application. This includes things like memory footprint and CPU load but will also have detailed information about the entire callstack of the code that was run. To enable the profiler part of XDebug you just need to set up a few rules in your xdebug.ini file.

I have started to use virtual machines to develop sites rather than installing a local web server. This allows me to replicate the exact setup of the server I will be deploying to with ease. For each virtual machine I set up a shared folder which allows me to store the files locally whilst being able to run the code on the virtual machine. One thing I missed was the ability to use xdebug to debug the sites through Netbeans, so I set about trying to set up the virtual hosts to allow me to use xdebug remotely.

All that is needed was to add a xdebug.remote_connect_back clause to the xdebug.ini file found in the PHP configuration. Set this value to 1 to automatically connect back to any xdebug session that is created on the server.

I have talked before about running Selenium tests in PHPUnit but I have only recently come to properly automate things. Getting a Selenium server to start and stop in a script is relatively easy and can be done in a simple script. My original script for running a directory of PHPUnit tests was as follows. I will explain more about how this all works later on in this post.

I was at a meeting of the Manchester Web Performance Group the other day where Tom Taylor gave a talk about some of the performance testing tool he uses at Laterooms.com. He used a ruby script to set up some preferences in Firefox which then ran Selenium to open some web pages and test them with YSlow. The results of the YSlow inspection are then sent to a Show Slow server where the results can be graphed over time. I realise that I've just mentioned a whole stack of technologies there, so let me pick out the important ones:

Selenium is a remote control agent for web browsers, although it is most stable in Firefox. I have written about this tool before but it allows us to automate interaction with a website via a series of selenium scripts. These scripts can be exported into different code formats, including PHP.

I recently saw an implementation of a Twitter wall that used node.js to run searches on Twitter and post the results on a webpage. I had been wanting to create something using ReactPHP so I thought this was a good opportunity to have a go. ReactPHP, if you haven't heard of it, is an event-driven, non-blocking I/O that is essentially the PHP equivalent of node.js. The major difference is that ReactPHP is written in pure PHP with no extra components, whereas node.js is a collection of different programs, interfaces and languages. As a first attempt I wanted to create something simple so it needed to use simple JavaScript to load in the latest tweets for a given hashtag from a ReactPHP server. I have to warn that this is a simplistic implementation of ReactPHP, but it shows the basics of how to get started.

Checking Syntax Errors In PHP And JavaScript Using Phing

Running a simple syntax check over your files is a good way to save time. This can be when testing code but best practice is to not to even commit code that contains syntax errors.

You can syntax check a single file using the -l (lowercase L) flag with the PHP executable like this.

$ php -l file.php

Unfortunately this can only check one file at a time so I set about trying to find a good way of checking a whole project at once. There are a couple of scripts available on the internet, but I set about creating my own solution using the phplint task in Phing. This means that I can just create a fileset and feed this into the phplint task without having to rewrite the whole thing if I wanted to include (or exclude) a particular directory or file.

When posting happy birthday messages to developers over social media I like to write it in code, just to be geeky. The following code will print the happy birthday song using PHP.

<?php
$string = '';
for ($i = 0; $i < 4; $i++) {
    $string .= "Happy birthday ";
    if ($i != 2) {
        $string .= "to you!\n";
    } else {
        $string .= "dear %s!\n";
    }
}
print sprintf($string, 'name');

This can be easily personalised by just changing the second parameter in the sprintf() function.