Category Archives: opinion

Strange behavior in PHP with method visibility

Normally I feel very comfortable with PHP, but not all is good. There’s some things I don’t like. One is the lack of real annotations and another one is this rare behaviour with visibility within the OO. Let me explain this a little bit.

Last week I was refactoring one old script. I removed a coupling problem with DI. Something like this:

class AnotherClass
{
    protected function foo()
    {
        return "bar";
    }
}

class OneClass extends AnotherClass{
    private $object;

    public function __construct(AnotherClass $object)
    {
        $this->object = $object;
    }

    public function myFunction()
    {
        return $this->object->foo();
    }
}

$anotherClass = new AnotherClass();
$oneClass = new OneClass($anotherClass);

echo $oneClass->myFunction();

It works, but I realized that I didn’t need to extend OneClass with AnotherClass (due to the DI), so I removed it. Then the script crashed:
Fatal error: Call to protected method AnotherClass::foo() from context ‘OneClass’

Obviously it was due to the protected function AnotherClass::foo. But, Why it worked when I extends OneClass with AnotherClass? The visibility is the same.

I reported this “bug” to the PHP community. PHP community is great. I had an answer very quick. It was not a bug. I needed to read several times the answer to understand it but finally did it.

As someone answer me:

foo() is protected and was defined in the context of OneClass. The access is done in the context of AnotherClass. AnotherClass is a subclass of OneClass (the context where foo() was defined). Therefore access is granted

In PHP the visibility belongs to the class not to the instance of the class. I understand the reason, but my mind compute it as a bug :( and it isn’t. It’s a feature.

What do you think?

Deploying tips for Web Applications

I’ve seen the same error in too many projects. When we start a project normally we start with a paper, a white board or something similar. After the first drafts we start coding. In the early stage of the project we want to build a working prototype. It’s natural. It’s important to have a working prototype as fast as we can. The things are different in a browser. All works within a white board, but with a working alpha release we will feel “real” sensations.

Now the project is growing up. Maybe we need several weeks to going live yet. Maybe we haven’t even decide the hosting, but there is something we need to take into account even in the early stages of the project. We need to build an automate deploy system. The way we’re going to use to put our code in the production server. It’s mandatory to have an automated way to deploy our application. Deploy code in production must be something really trivial. Must be done with a few clicks. Hard to deploy means we are not agile, and that is not cool.

If the project is a “professional” one (someone pay/will pay for it), problems in the deploy means down times. Down times are not good. Our clients don’t pay us for those kind of problems. If the project is a personal project, a hard deploy system means that we’re going to be very lazy to improve our project. Deploy by hand is good idea only if we never forget anything and if we’re perfect. If not, it’s always better to have a build script.

It’s important to define different environments within our application. Modern frameworks such as symfony2 has a great way to define environments. It’s important to take into account that. Our code must be exactly the same in our development environment and at the production one. Exactly the same means exactly the same. If we need to change the code before deploy it into production server we’ve got a problem. A simple trick to define environments is create two ini files one with development data (database dsn, urls, paths) and another one to production. We can also use enviromnent variables, but keeping the source code identical.

So we need at least a build script to the source code, but we must remember that we also need to deploy database changes. Deploy database changes is a hard work, but source code can be trivial if we take into account a few details:

  • Source code must be the same in all environments. Differences must be placed in configuration files.
  • Never perform file-system operations directly with the console. We need to create scripts and execute the script to perform file-system operations. (folder creation, write-enables to log and caches, …)

If we follow those simple rules we can create a very simple build scrip with our scm (git, mercurial).

The idea is very simple. One mercurial repository on development server. Another one on production server.

// .hg/hgrc
[paths]
prod = ssh://user@host//path/to/app

[hooks]
changegroup = hg update

Now we can easily clone the development repository. A simple “hg push prod” will push code to the production server and update the working repository. If you don’t have ssh access to the server maybe you need to build a custom script. Please do it. “Waste” your time creating your build script. It must works like a charm. Your life will be better. Another tools that will help us to build deploy scripts:

http://capifony.org/
https://github.com/capistrano/capistrano
http://www.phing.info/trac/

And that’s all. Regards, Gonzalo

Looking for the perfect PHP IDE

I’ve got a problem. I haven’t found the perfect IDE for me. Yet. I’ve got problems with every software. Now I will try to explain the problems I have and maybe someone shows me the light and helps me to discover the perfect editor/IDE.

First important thing. I’m a Linux user so Windows only softwares are out. I know Mac user really love Textmate but buying a mac is not in my scope. They are good hardware, reliable and of course cool. I know nowadays there are a lot of web developers working with mac but I’m not convinced yet to change my computer from PC with linux to mac. Probably I will make myself the question when the core breaks down. Don’t ask me why but my last three PCs broke down with a fail the core (after years of usage). So the baseline is clear. Software must work with linux and it must work in a native way. Not with wine or things like that.

My requirement list is the following ones:

  • Code auto-completion.
  • Syntax highlight.
  • Debugger.

Easy, isn’t it? But even with those simple requirements I haven’t found yet my perfect IDE. So I’m going to enumerate the problems I’ve got with each one.

Zend Studio 7

It’s not free. That’s not the main problem. But we can find another similar for free. Debugger works fine. Code auto-completion really good. Syntax highlight perfect. Auto indentation and one of my favourite feature code analysis. Really useful. It detects problems such as:

$var = 0;
if ($Var == 0) { // $Var and $var are different variables. It’s probably a type error very difficult to detect in a glance
	...
}

It’s look like the perfect IDE but it’s maddeningly slow. If you are working with a few files is perfect but is your project is big (hundred of files) sometimes you are forced to make too many coffee breaks when it becomes crazy (building workspace…). Maybe if you’ve got a super pc with infinite RAM and hundred cores it works fine but, at least for me it’s irritating.

Eclise PDT

Zend Studio 7 is based on eclipse. PDT it’s almost the same than Zend Studio 7 (without its great integration with the zend services that I don’t use). Exactly the same problems (very slow) but even without some extra features, such as code analysis (really useful for me). By other hand it’s free (as free beer)

Netbeans

Similar features than Eclipse PDT and lighter. Also free. The problem here it’s the debugger. Only works with xdebug. Not a real problem for me. I don’t really mind what debugger to use. Zend debugger and xdebug meets my requirements. But it’s a bit strange how to debug. I don’t like it. In early versions it created the url when you started to debug. And that url cannot be changed properly. That’s means it doesn’t worked for me. Now it’s better but still not good. It looks like the PHP plugin of Netbeans isn’t as good as Java one’s. The future of Netbeans isn’t clear with the acquisition of Oracle. They said Netbeans isn’t an strategical project (that’s means they cut some funds)

VIM

It looks like the perfect editor but It’s hard to learn, at least in the beginning. Syntax highlight perfect. Really light. Works perfect everywhere even on remote hosts via ssh. Code auto-completion works but not as good as in eclipse and Netbeans (but it’s fair enough). I said is not as good as Eclipse and Netbeans because for example it doesn’t hint me with the variables of the function or ignores PHPDoc in the auto-completion pop up, and I really appreciate it. The main problem I have is with the debugger. It’s so strange for me. I thing I need a couple of hours working on it because nowadays debugging with VIM is something like a miracle a miracle for me. Sometimes work but I it’s too many endeavor. Yet. I hope so. If you want more about about PHP and VIM, you must take a look to this link.

Emacs

I must admit that I am too lazy to learn to use it. I invested time with VIM. I feel that I need more and I don’t want to start with another one like emacs from zero. Maybe I’m wrong and that’s the perfect IDE but it’s not in my mind now.

Zend Studio 5.5

That “was” the perfect IDE. It was not for free but it was really good. Fast. Even with big projects (sometimes become crazy and crashed, I known). Debugging was perfect. Only with Zend debugger but really easy to use. You don’t need a great pc. 2G RAM was fair enough. But there’s a problem. This software is obsolete. Zend changed to an Eclipse based one. We can still using it but there isn’t any update. The main problem with it is we cannot use any new PHP5.3 features, such as namespaces. OK we can use them if our server has PHP5.3 but IDE mark those new keywords as syntax errors. So If we work with this software and a PHP5.3 project we need to assume that the red warnings of our editor (syntax errors) are not always errors. It’d be a great new for me if Zend people releases Zend Studio 5.5 as open source a someone continues the project adding PHP 5.3 support.

As you can see I’m not 100% happy with any IDE. Do you have a perfect IDE? I’d really like to be wrong in my assumptions. So I’ll keep looking for.

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