When programming in any language there are certain common errors that everyone makes as they mature and evolve their programming skills. In the case of PHP, I’ve seen a lot of ugly and complicated code around, since the language is very permissive.
To have a good and healthy PHP code base so it won’t resemble the unmanageable cabling mess in the picture above, your project needs to have the following:
- no spaghetti code
- code reuse (avoid code repetition)
- avoid complicated nested loops
- Encapsulation (organize code in classes)
- Clean user I/O
- Code Documentation
- Consistent code conventions
Luckily there are some PHP code quality tools that can help us address most of these problems and give us a diagnostic of our project’s code health.
Documenting your code
PHP Documentor: Documenting code with PHP Documentor is very simple and easy. You just need to follow a very simple markup before your functions and classes and the tool will generate all the developer documentation for you. It’s also very handy when adding new people to your project or inheriting someone else’s work. Just by seeing the documentation comments in the code you can understand what a given function does, what each of its parameters need to be and what it returns. You can also expand the documentation to add use cases and even unit tests!
PHP Code Sniffer: A tool that analyses the syntax of your project’s code based on a PHP syntax standard. Known standards like PEAR or Zend syntax styles are included by default but you can also customize and define our own team’s style.
PHP Depend Analyzes the code for common issues and potential optimizations. Some examples of those are:
- if your function is too long
- if your function has too many parameters
- variable names too long or too short
- too many nested cycles
- use of eval()
- name convention consistency
- unused methods or variables
PHP Mess detector: A fork of PHPDepend with a friendlier UI and configuration options
PHPCPD (Copy/Paste Detector): A tool that will detect copy/pasted code across your project that can be reused.
PHP Unit and Simpletest: Unit testing has been very useful in my experience on recent projects where I’ve been allowed to implement it. On personal project I always tend to do unit testing before layout out all my code. It might take more time to develop your project at the beginning but it will save you tons of time debugging and tracing back errors when you think you’re done programming.
Integration Testing (browser emulation)
Put it all together with Phing
Phing is a tool like GNU Make or Apache Ant but it’s in PHP and extensible via PHP classes. You can put all of these tools together with Phing, so you can automate all the checking, testing and even deployment and cleanup of files or databases.
With these tools you can have a very robust quality assurance workflow on your project. Of course, this doesn’t mean that there’s not going to be any bugs or that your project will have the best code, but at least it will reduce very common problems, will increase code maintainability and help you spot problems easier. The transitions from adding or removing people from the project (like in large teams or dynamic organizations) will be smoother, as well. Also those transitions will be even smoother if you consider using an established web framework for your project instead of writing your own.
I gave a talk at FSL Vallarta 2012 about this, you can download the slides for the talk “Herramientas de calidad en codigo PHP” here. (slides in Spanish)