Catching PHP Exceptions: Except the unexpected

PHP Exceptions can greatly assist in implementing various error scenario’s into an application. Before PHP5 one had to resort to specific return values or drastic measures like trigger_error(). Planning exceptions, I found out, is just as important as class design. At any point where a developer needs to handle the possibility of an exception being thrown he needs to know:

  • What Exceptions can I expect?
  • What Exceptions do I plan to catch?

In this post I’ll show some important aspects to consider when planning exceptions.

Keep reading

Usability: What does this button do?

In software development projects, paying proper attention to usability aspects, can greatly help ‘getting the message functionality across’. Usability is a field of expertise on its own and involves techniques like wireframes, prototyping and card sorting. Not every project is the same and (sadly) lack of time or budget can prevent specialized interaction designers to be involved in the project. This means that making the application ‘usable’ becomes the responsibility of graphic designers or developers (or it is neglected altogether). Not an easy combination of tasks…

Keep reading

PHPBenelux meeting at Freshheads

Yesterday (sept. 29th) I went to the Freshheads office in Tilburg to attend the monthly PHPBenelux meeting. As it appeared it was right around the corner of the 013 venue so it was an easy find. Two talks were scheduled and Stefan Koopmanschap kicked off the meeting with a presentation titled “Integrating Symfony and Zend Framework” (slides). After a short introduction pointing out the benefits of using any framework at all, Stefan showed how both Symfony’s and Zend Framework’s autoloaders can be initialized in the application’s bootstrap code.…

Keep reading

Taming the Javascript event scope: Closures

When doing client-side developing there are times that jQuery’s get-this-do-that nature doesn’t provide all that is needed. For more complex applications I usually find myself creating javascript objects that ‘control’ a specific part of the page’s interaction. In the objects the application’s state is tracked, references to other objects (could be relevant DOM nodes) are stored and event handlers are set.

One of the problems typically encountered when dealing with javascript event handlers is that they have their own take on the ‘this’ keyword. Closures to the rescue.

Keep reading

Controlled initialization of domain objects

In a recent project I’ve been working on, we have used the ‘Domain Model‘ to describe and design our application. Doing so we decouple persistency logic from the objects that are being passed around and modified throughout our application: The Domain objects. So what in MVC is often referred to as ‘model’ is actually a combination of a persistency layer, a service layer and a Domain layer. The persistency and service layer are also referred to as Data Access Objects: DAO. (As for the why and how of this architecture I recommend the article Writing robust backends with Zend Framework. For a good description of the DAO concept look here).

One of the challenges we were facing was that on one hand we wanted to implement business rules in our Domain objects. In plainish english: On setting or changing properties of the object (like changing a status) we want to validate if that action is allowed. On the other hand we want to be able to initialize an object to whatever state corresponds with the data fetched from the persistency layer. Doing so we found that the business rules got in the way during initialization when fetching it from the persistency layer. So what we were looking for was a way to allow the service layer to construct a Domain object using methods that are hidden from the rest of the code. We found two ways:

  1. Reflection (as of PHP 5.3)
  2. A design pattern where the Domain object initializes itself using the provided Service object.

Keep reading

DPC09 down, DPC10 to go

The biggest PHP event in Holland is over. Two great days have passed and it feels like it were just two hours. I didn’t attend the tutorial day so at friday after a brief intro by Cal Evans (with great cartoony visuals) the event kicked off with the opening keynote by Andrei Zmievski. A talk about what makes PHP the language it is and about where PHP is heading with 5.3 and 6. It had humor, appealing imagery and a nice metaphor comparing PHP to a ball of nails: ‘whatever you throw it at it sticks to’. For me what showed the maturity of PHP, was the fact PHP6 is undergoing (or will so) compatibility tests with respect to packages like Drupal, WordPress and Zend Framework.

Keep reading

Explicit PHP6?

Some days ago I read Fabien Potencier’s post ‘What for PHP 6’ pointing me to some features that might be implemented in PHP6. Two of those would have been nice in a project I’m currently working on where I’ve been experimenting with ‘domain objects’ having ‘scalar’ or ‘value’ objects as properties (more on that later). The first is scalar type hinting and hinted return values. The other is a __cast() method that replaces (or complements __toString()). Now that sounds quite java-ish and one of PHP merits is it’s flexibility but having the option to be more strict in my opinion is a good thing: If I feed my application with garbage I don’t blame it for being equally blunt.

Keep reading

Zend_Test, Zend_Layout and the need to reset

In a recent Zend Framework project I’ve used Zend_Test to test the functioning of the website ‘as a whole’. So besides testing the separate (authorization) components, the website was tested in the same way a visitor would use it. This is especially useful for testing login scenarios, so I added the test below:

public function testLogoutShouldDenyAccess()

         // verify that profile page now doesn't contain login form
    $this->assertQueryCount('form#login', 0);

        // dispatch logout page

        // verify that profile now holds login form
    $this->assertQueryCount('form#login', 1);

This failed on the last assertQueryCount() which left me puzzled. Performing above steps manually seemed to work fine so I was overlooking something either in my app-code or the test-code.

Keep reading

Installing PHPUnit on XAMPP Lite (Windows)

At my work PHPUnit is ‘just there’ but it’s not on my home machine where I’m running an out of the box XAMPP Lite setup. So I visited the PHPUnit installation manual and all looked easy:

pear channel-discover
pear install phpunit/PHPUnit

But what I got was a message saying my pear installer was out of date, 1.7.1 was needed. Running ‘pear -V’ showed:

E:\Xampplite\php>pear -V
PEAR Version: 1.4.5
PHP Version: 5.2.5
Zend Engine Version: 2.2.0
Running on: Windows NT T1720 6.0 build 6000

Allright, upgrading PEAR it is. That was not as straightforward as hoped.

Keep reading

Fixing Netbeans after Ubuntu 9 upgrade

This morning I upgraded my Ubuntu machine using the auto-update. As I just recently started using Ubuntu I’m very pleased at how some features work compared to Vista. (Vista users will probably be familiar with the auto-update restart that has a terrific feel for timing by always presenting you the choice for postponing the restart when you have several documents opened and are away for a coffee break.) After my self initiated restart everything worked like a charm, OpenOffice is updated to version 3 (nice for the docx workflow) but… Netbeans didn’t start.…

Keep reading