PHP

If there is one thing in the PHP world that really annoys me it's programmers writing what I call "lazy code". This is code that works but takes the least amount of time (generally meaning keystrokes) to create. This is almost always a bad thing as it is difficult to read, hard to change and almost always uncommented. The main problem is that PHP is quite a forgiving and fluid language in that you allows you to write code in a variety of different ways and formats.

The most common problem I have come across with lazy coding is when programmers write if statements. These can be written in a variety of colourful ways, the most common approach I have found is to leave out the curly brackets, like this:

To convert a time value into a decimal value representing the number of minutes can be useful for certain calculations. The following function takes a time as a string of hh:mm:ss and returns a decimal value in minutes.

/**
 * Convert time into decimal time.
 *
 * @param string $time The time to convert
 *
 * @return integer The time as a decimal value.
 */
function time_to_decimal($time) {
    $timeArr = explode(':', $time);
    $decTime = ($timeArr[0]*60) + ($timeArr[1]) + ($timeArr[2]/60);

    return $decTime;
}

If we take the time of 11:11:11 this gets split into 3 parts by the explode() function into hours, minutes and seconds, which then gets treated in the following way:

Minutes = (Hours x 60) + (Minutes) + (Seconds / 60)
Minutes = (11 x 60) + (11) + (11 / 60)
Minutes = (660) + (11) + (0.18333333)
Minutes = 671.18333333

The function can be used as follows:

I have looked at printing an intelligent list of WordPress pages in a previous blog post, but I wanted to revisit this topic and use the Walker classes that are part of WordPress. The Walker class is an abstract class that sorts out a lot of the basic functionality needed to extract and render a hierarchical list of items from a database. It is essentially an iterator class that understands lists of items that contain lists of items and can be used anywhere in WordPress where this structure is needed. The Walker class can be found in the file wp-includes/classes.php along with four other classes that extend Walker, these are.

This weekend saw the 3rd PHPNW conference and being a PHP developer, working in Manchester, it would be inexcusable for me not to attend :). After missing my train and pouring my first coffee of the day into my conference pack it wasn't the best of starts. However, I still managed to turn up in plenty of time so I didn't miss any of the talks and got to say hello to the people I know from the PHPNW user group and some who I met at the PHPNW conference in previous years.

Day 1

Keynote: Teach a Man to Fish: Coaching Development Teams
Lorna Mitchell @lornajane

The UK PHP TestFest this year was held at MadLab in Manchester on the 11th September. I was one of the 12 people who went along to learn about testing the PHP language. So I thought that I would collate some of the things that we went through during the session.

Before creating a test you need to set up your testing environment, you can do this by going to the TestFest site and running through the tutorial on setting up your system for testing PHP. When you have finished setting up your test environment you will have a folder containing three folders, these are php52, php53 and php-trunk, these are the different versions of PHP which you can test, although we will be concentrating on the php53 version in this article the same practices can be used for the other trunks.

When displaying images added by users it is quite often necessary to resize them in order that they fit into a specific area of the page. Not doing this can cause problems with the images breaking the page layout. The trouble is that if you resize the image absolutely you tend to squash and distort it.

The following function can be used to calculate the width and height of an image to the correct aspect ratio, which will preserve the contents when printed out. This function makes use of the getimagesize() function, which is available as part of the GD library in PHP.

Different functions and options are always being added to PHP. Although new versions generally don't create much backward compatibility issues it is usually prudent to write production code that you know will work on servers running a slightly older version of the language.

To check the currently used PHP version you can use the function phpversion() or the constant PHP_VERSION. Both the function and the constant return a string that contains the version number. There are a couple of ways in which this information can be used, the first is to take the string and convert into an array using the explode() function. With this array you can then check the minor version number and run code like the following:

I quite often find the need to extract a section of text from the beginning of a blog post or similar to be used as the excerpt. I normally use a function that will count the number of whole words available and return the string containing those words.

A good alternative to this, although only applicable if the original post is in HTML, is to use a regular expression to extract the contents. The following code will take a string and extract just the first paragraph of text.

If you need to know the month from a given integer (from 1 to 12) then you can use the following snippet. This will return the string "Feb".

date("M", mktime(0, 0, 0, 2));

This can be encapsulated into a function call that will take a number between 1 and 12 and return the corresponding string for that month. This function includes some simple error checking to make sure that the number is valid before trying to work out the date.

function getMonth($month) 
{
  if (!is_numeric($month) && $month  1 && $month > 12) {
    return false;
  }
  return date("M", mktime(0, 0, 0, $month));
}

Richard Wiseman is a psychologist, magician, and author who runs a little blog over at http://richardwiseman.wordpress.com/. His blog talks about all sorts of things, but every Friday he posts a little puzzle that you can have a go at solving.

The last puzzle posted talked about palindromic numbers and speed, here is the puzzle in full.

The other day I went for a bike ride. My favourite route has signs every meter saying how far you have travelled. I came across the sign saying '15951 meters' and thought 'Oh, that's interesting, it is a number palindrome because it reads the same from left to right as right to left'. Then I rode on. Two hours later I came across the next palindromic number sign. How fast was I going?