One of the nice things about storing collections of data in arrays rather than objects is the fact that you’re able to easily loop through the collection, and extract data from the collection depending on the position. Sometimes though we may want to manipulate the collection, and store more information than just the data in the collection. This is where SPL comes in.

As of version 5.0 PHP has included the SPL (Standard PHP Library). I am going to look at a couple of interfaces from this library in this blog post: ArrayAccess and SeekableIterator. These interfaces allow us to do a couple of things: SeekableIterator allows us to iterate through the object (eg. a foreach() loop), and the ArrayAccess allows us to extract data from the object as if it was an array. All this in a way that is completely controlled by the programmer.

Definition for the SeekableIterator:

SeekableIterator extends Iterator {
/* Methods */
abstract public void seek ( int $position )

/* Inherited methods */
abstract public mixed Iterator::current ( void )
abstract public scalar Iterator::key ( void )
abstract public void Iterator::next ( void )
abstract public void Iterator::rewind ( void )
abstract public boolean Iterator::valid ( void )
}

Definition for the ArrayAccess:

ArrayAccess {
/* Methods */
abstract public boolean offsetExists ( mixed $offset )
abstract public mixed offsetGet ( mixed $offset )
abstract public void offsetSet ( mixed $offset , mixed $value )
abstract public void offsetUnset ( mixed $offset )
}

The way these work is that they require a variety of methods to appear in the class. With SeekableIterator there is generally a “position” property which is just an integer holding the current position in the collection (so normally defaults to 0). The methods that are required are: seek, current, key, next, rewind and valid. The “seek” moves the position to the number passed in as an argument, “next” method normally increments the position by one, and “rewind” resets the position back to 0. “current” returns the item at which the position property is at, “key” tells you the current value of position and “valid” checks to make sure an item exists at that position. You can then put the object in a foreach loop as if it was an array!

foreach($iterableObject as $item {
     ...
}

ArrayAccess requires fewer methods, and some of them are similar: “offsetExists” is the same as “valid” but rather than getting the position from the internal position property, it is passed in as a parameter. “offsetGet” returns the item at a given position and “offsetSet” sets an item to a given value. You can then treat an object like an array by using standard array notation:

$item = $arrayAccessObject[0];

A single class can implement both of these interfaces without conflict, and SPL contains many more things like this. I have not written this as a tutorial as the PHP Docs are incredibly good on this subject and easy to follow.

http://php.net/manual/en/class.seekableiterator.php
http://php.net/manual/en/class.arrayaccess.php

Log on to your server as root (either directly or using sudo su), then install the Memcache daemon through apt:

apt-get install memcached

Once installed you need to install the Memcache module into PHP. This is done through PECL which in turn is installed through PEAR. When they are both installed, you need to run the command:

pecl install memcache

This will install the memcache extension, and once done will tell you to add the the line “extension=memcache.so” into your php.ini file. I prefer keeping these in separate files (so that the php.ini file can be updated). The easy way to do this is:

echo "extension=memcache.so" > /etc/php5/conf.d/memcache.ini

And finally, reload Apache

/etc/init.d/apache2 reload

If successful, Memcache will now appear in your phpinfo().

article,aside,details,figcaption,figure,footer,header,hgroup,menu,nav,section,summary{
  display: block;
}

Unfortunately there is still a range of browsers which still don’t render HTML 5 objects. This means we need to add a JavaScript hack. Rather than downloading or creating your own JavaScript file, you may as well just link to a file that has already been created for you on Google Code. This means that it will always be kept up to date. Also as it is only needed for IE browsers up to version 8, you won’t need other browsers to load it:

<!--[if lt IE 9]>
<script src="http://html5shiv.googlecode.com/svn/trunk/html5.js"></script>
<![endif]-->

You are then free to start creating your HTML 5 web page!

Why should I spend £38 of my student loan on this?!

There is the saying “it’s not what you know, it’s who you know”. This is not strictly true, however there are definitely elements of truth in this saying. At university you learn a lot about a wide range of things around your subject. This is very important in order to gain a well-rounded education (see my Breadth vs Depth article) but if you know the area you want to go into once you graduate chances are you’ll want to gain more specific knowledge.

Professional conferences will give you insight into what people are doing in the professional world. As a student you are often isolated within a bubble. This bubble contains the information you need to gain good marks on your exams/coursework, but does not necessarily reflect what is happening in the profession. This is your chance to learn from people in that profession. Use their experience to give you guidance and an insight into what you may end up doing yourself.

Conferences are not just a load of lectures happening. A lot of what’s important (and indeed a lot of what you learn) takes place in the breaks, meals and of course – in the bar! Through having conversations with other delegates you can get even more insight into what it’s like to work in this industry and also will allow you to get to know people in the industry. This is where you can pick up contacts and even potential placements (if you’re on a sandwich course) or employment for once you’ve graduated. This may not come in terms of a job offer, but showing your face at these conferences prove that you’re keen and interested. It will also be beneficial in at least being slightly familiar if a job opportunity comes up with someone you met there.

Finally, there is the CV. You can put on your CV and application forms that you attended this conference (of your own accord with your own money) so you could learn more about the profession in your own time. This shows dedication and interest. Potential employers hold this in high regard and can set you apart from other candidates going for the same job. Particularly if you are able to talk about what you learnt.

OK, you’ve convinced me! Should I do anything to prepare?

Yes, it is highly recommended, particularly if you are not overly familiar with the subjects being talked about. There is a variety of talks; some are basic/beginner, some more advanced. All talks will assume knowledge of PHP (after all, this is why we’re here) and experience with a LAMP (Linux, Apache, Mysql, PHP) server setup will be very beneficial as this is the most common platform for PHP development. You should also look at the talk schedule and read up about the areas surrounding the talks, as this will give you some context for the talk and also help you decide which talks you are most interested in.

When coming to the conference it is recommended that you bring a laptop (if you have one) with a full battery. There will be power points available, but generally not in the rooms with talks and people will be fighting over them in the breaks. A laptop will allow you to do extra research around the area as well as communicate with other people on at the conference (via IRC, Twitter etc..). Finally, come and say hello before the conference in the official PHPNW IRC channel: #phpnw on freenode, and don’t forget to book your ticket!

In order to do this, you need to create a new virtual host in your Apache config. Create a new file in the directory /etc/apache2/sites-available and open it in your favourite editor. It doesn’t matter what the file is called, but it’s best to keep it descriptive. We’ll call this project “mysite”, so the file can be called “mysite”. In the file we need to configure the Apache virtual host.

<VirtualHost 127.0.0.1>
ServerName mysite.localhost
DocumentRoot /var/www/mysite/public/
</VirtualHost>

In the VirtualHost tag, you put the IP, seeing as I only want this for local loopback (for development) I have just put 127.0.0.1. The ServerName is the URL that you use to connect to the site and the DocumentRoot is where the public documents are stored. This is a very basic set up, so there are many more options you can add.

To make the site enabled, you create a symbolic link to the file from the sites-enabled directory.

cd /etc/apache2/sites-enabled
ln -s ../sites-available/mysite mysite

You now need to add the subdomain (mysite.localhost) to the list of hosts, so open /etc/hosts in your favourite editor and append the line:

127.0.0.1 mysite.localhost

And then restart Apache:

sudo /etc/init.d/apache2 restart

Now you should be able to visit http://mysite.localhost on the local machine (assuming the directory does actually exist).

This should also be similar on MacOS and other linux Distros, but the file locations (particularly for Apache) will vary.

In the past I have found Netbeans to be pretty good with code-completion when being used with Zend Framework, however with the release of Zend Tool (something I do really like), you’ve had to switch from Netbeans to the command line in order to create the project and then create a new Netbeans project from existing sources. This was a bit of a hassle.

Now, all you need to do is download the Framework, go into the Netbeans preferences > PHP > Zend tab, Zend script box should point to the zf script (from within the bin directory of the ZF downloading). On Mac and Linux it wants the zf.sh file (on Windows it will probably want the zf.bat file, although not tested). Once that has been set up, you can now create brand new Zend Framework projects from within Netbeans, and it preconfigures everything for you. Lovely!

Many web developers are all too aware of the pain of getting their websites working correctly in all web browsers and THEN having to make sure they work in IE6. This is not only inconvenient and irritating, but expensive. However, with Google announcing it is no longer supporting IE6 and now Amazon following their lead, it is appearing that very soon (not immediately) people will be forced to update/change their web browser to use these large and prominent websites. Many other sites have also dropped IE6 support (list at http://idroppedie6.com/).

Finally we will be able to spend our time on functionality rather than legacy support.

Here are the slides