Topbit Technicals

Just a quick note on what is going to be posted in the next few weeks – I’ve got a few significant pieces in mind for various topics – including:

• Doing the work elsewhere – asynchronous queues

This is going to be a series of articles – and to support it, I’m rewriting some code that I had originally wrote for my last job (v2, and so significantly improved over the original). First though, I’ll tell you what is planned, and just how asynchronous queues are used and how they can be incredibly useful for scaling up any significant website, and not just in the obvious ways.

• Mail queuing, on a vast scale

Dave Marshall has just posted an entry on “Using message queues to improve user experience”: http://www.davedevelopment.co.uk/2009/06/01/using-message-queues-to-improve-user-experience/ where he queues up some emails in order to spool them out over the course of a few minutes. For the last 18 months, I’d been doing something very similar, on a far larger scale, with PEAR’s Mail_Queue. I’ll show you how I did it and I’ll show you how the messages were generated quickly, and how they could be sent out – and more importantly without destroying the system it was running on. As a bonus, I’ll show you how if you run some form of internal mail system, you could save gigabytes of database space and give yourself vastly more flexibility.

• Self stubbing mocks

Using the Mocking functionality in PHPunit & Simpletest can be complicated with the various calls that are required. There’s just not much documentation around the PHP-world on how to run it. Another method, which can be easier to understand, is self-stubbing – putting your code into the test class. I’ll show some examples of how to do that.

Finally, I’m going to be doing my ZCE exam in the next week or two – quite possibly on Thursday 3rd June. Keep a close eye here, and on my Twitter @topbit for the results, and a follow-up.

see my previous post on the topic, #1.

My last post ended up more as a how-to than what-to. This time, I’ll say why you should have local copies of the documentation for most of the tools you use. I’ll also tell you the sort of things I always have handy as well.

Getting a local copy of php.net – and getting installed as an apache vhost and updated (probably weekly) is some effort, but well worth it. I’ve said it before, but PHP.net is the best language reference site that I’ve seen. It’s kept up to date (sometimes ahead of the code releases in fact) and while the notes that are added to it can sometimes confuse, as much as help, when they do help, they will really make the difference.

I don’t tend to buy many PHP books, because what can they do besides re-iterate what is is already there?

The most important thing to bear in mind though is not to just have the documentation there to read – you have to know what is available. Projects like PHP, the Zend Framework and PHPUnit have a lot of parts – and knowing that they have things – even if you don’t know how they work right now, can save you days or weeks of effort.

It’s for that reason that you need to at least scan over all the the docs you have – and indeed for all the libraries and tools that you use. Even I don’t read everything and expect to remember it all – but I remember enough to recognise that a paticular tool might have something to help – maybe PHP has something to search the values in an array (http://php.net/array-search), or can use Oracle, or Ldap, or Memcached, or that Zend Framework can let you easily loop over maildirs (or an mbox) to get each mail from within it. If you don’t read the manual – at least skimming over it, you would never know that functionality exists, and you inevitably end up reimplementing other people’s already debugged code. That’s a waste of your time.

So, take an hour now, and assemble a directory to put these docs into, and read through them – not everything, but at least look at headers of every section, just to get an idea of what is available and maybe go back and read up some more on things that may be useful to you. If something isn’t so interesting to you now, do bear in mind, your next project, or job, might change that.

Above all, keep learning. Never stop.

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Continue reading "Always have up to date documentation, part #2"

Just a quick tip here, and I’ll expand on it below the cut.

When you have a library, like PEAR or Zend Framework – or ven just the whole PHP language library – it’s absolutely vital you know what it can do.

What you don’t know can cost you weeks of effort and pain. I found this out (again) today, but it’s not my pain – it’s an employee who was too busy deciding that the Zend Framework wasn’t suitable for a simple cron-script task, he has spent most of the last few weeks duplicating something that is not as good as what I could write – with ZF – in about an hour.

Continue reading "Know thy tools first of all"