PHP for desktop, is it worth it?

PHP is described on Wikipedia as:

PHP: Hypertext Preprocessor is a widely used, general-purpose scripting language that was originally designed for web development to produce dynamic web pages.

Taking this into consideration, apps divide in 3 category: web, command line and desktop.

For the Web, PHP is the most popular open-source (and not only) programming language.

PHP CLI

PHP CLI (Command Line Interface) I find it very interesting, even though is not used at it’s full potential. A lot of developers prefer shell scripting or Perl with no real reason. I’ve been playing around with this tool and I liked the result.

Important frameworks like: Zend, Symfony or Cake PHP are using PHP CLI to generate projects, models, CRUD or other features that can be easily used with a command line.

In the Windows environment the command line is not exactly popular, but in Linux is almost imperative. After all what’s the point of using shell scripting when you can use a powerful language with a lot of features like PHP?

But CLI is not limited just to the command line, it is usually used for cronjobs, pipes, socket-servers etc.

PHP-GTK

When it comes to PHP and desktop usually people thing about PHP-GTK. What do I thing about the project? Is not dead, like it says on the official website, but is not exactly alive. The reason? Gtk is not exactly simple. If you come from the Linux environment probably is not that difficult, but if you usually work on the web is not exactly html… Nevertheless there is a community that keep this project alive.

Nevertheless, it allows developers to build desktop apps in PHP, compatible with a wide variety of operating systems.

But there is an issue, the resulting apps are not exactly compiled code, they must run using a PHP virtual machine. Here is the issue, how do you distribute the app? If you have a small app of only few lines of code, to distribute it with a virtual machine is a little complicated… Also the code is visible, of course there are methods to solve this issue, but there aren’t exactly simple.

This is probabily the most popular PHP platform for desktop, if you can say that about this environment.

The documentation is pretty big, it was taken from the C++ version. Is not as well polished like the PHP manual for instance, but I believe is sufficient.

Winbinder

Compared to PHP-GTK it has an disadvantage, it only works on MS Widows operating system. The advantage is that it has a much simpler API. If I had to choose a PHP platform for desktop, probably I would go for Winbinder. Unfortunately is in the same state, is not dead but is not exactly alive. It also have the support of a community, but without any particular special results.

The issue with the compiled code is found here also, and even more the issue with platform distribution is just as bad. I firmly believe that if you want to develop an app using this platform, to make it work on your computer is the easiest part, to make it work on someone else’s computer is the real issue…

The documentation is pretty small, because of the API. But simplicity is good when it comes to programming, that means you can easily build pretty interesting apps.

Compilers

There a few, and the majority of them have some issue because they use old PHP versions of even old GTK. I’ve spend many hours on Google trying to find some reals solution but with no success.

Most popular compilers:

• Bambalam – works well with CLI and Winbinder. But it has a great disadvantage: it’s only compatible with PHP 4.4.4, and I believe that says it all. Anyway I believe it was the most interesting solution, unfortunately to old (the last version was released in 2006).
• PriadoBlender – works well with PHP-GTK and CLI, but is not very stable. The last (beta) version was released in 2007, and since then nothing new was ever heard from it. Probably if that version would be updated  it would help a lot the PHP-GTK project.

Conclusion

When it comes to Web, everything is great!

PHP as a command line tool is ever more popular and more tools appear each day!

In the desktop environment is a “the living dead” sensation… This projects are not dead but there not exactly alive. Of course there are other solution for PHP on desktop which I did not mention, but there are in about the same state. Probably a new approach would help, something more attractive for web developers and those passionate about this language.

CodeIgniter is an open-source PHP framework build for RAD.
The book CodeIgniter 1.7 from PacktPublishing, written by  Jose Argudo Blanco and David Upton is trying to build an overall image of of the CodeIgniter framework,  as an addintion to the user guide.

The book is not a reference, and that becomes obvious with every chapter, each time a new feature of the CodeIgniter framework is introduced the user is directed to the corresponding page of the module in the user guide or wiki. Even more, suggestions are made for alternative modules that can achieve a similar task in a different way.

Authors say that only minimal knowledge of PHP is necessary to read this book, a promise that is hard to keep in my opinion, usually books that target novice to medium skill readers are saying something like that. To my surprise they ware right, the reader only needs PHP4 knowledge. And when it comes to OOP not even PHP5 features are required, just the PHP4 object model. In this book even the copping objects by reference is described! Of course copping objects by reference is no longer a relevant issue with PHP5, but taking this in to consideration that is an PHP4 framework it was a good idea to mention and explain it. It seems like there are still PHP4 server on the Internet… that is just sad…

Reading the book flashbacks came to my mind with pieces of code written directly in PHP and the hell of debugging them, trying to understand other peoples code… what times… horribly of course. The reasoning behind this concepts of re usability in a framework is just  great: “Possibly you like typing regex. Some people like lying on a bed of nails…”. When a developer, especially a beginner, is reading something like this it makes him understand that you don’t have to reinvent the wheel each time, but just use solutions already developed by others.

Comparing between different available solutions I believe is the most funny part of a book like this. Is difficult or even impossible to compare for instance Zend Framework or even CakePHP with CodeIgniter. After all almost all frameworks say the same thing, just download and start working. Personally when I need to use a module from Zend Framework I just load the autoloader and get to work. The comparison shows CodeIgniter as a winner for most users, as expected, the reasoning behind that claim is pretty honest.  Afterall is a small framework and does not have complex features like autogenerating CRUD. I remember a Java book where the author was representing the fact that C++ is faster then Java as a disadvantage, of course was just silly.

I sometimes had the impression that the terms were wrongly defined. The authors are using “small” mistakes in terms to explain what’s actually happening in the background. When you are working with MVC frameworks some of the notions are simple and obvious, but for a developer that’s not familiar with that terms there are quite hard to comprehend.

And to continue with the mistakes in the book, I’ve found a few. Quite a difficult moment when you start learning something new. Fortunately there are quite obvious because they result in errors, and if you read chapter after chapter you’ll know what the issue is and how to fix it.

Examples are pretty consistent and well documented. When a new concept or module is introduced it is fully explained in detail.

The resulting apps are not very complex, for instance at the end of the book there isn’t a full complex app like a CMS, rather modules and the way there are combined is explained. The user will have to decide in the end how will his app look and feel. For instance in chapter 13 pagination and ordering is explained. When pagination is used everything is OK, but when ordering is introduced the pagination begin to slip. It took me about 5-10 minutes to fix the issue, but it would have been nice for the authors to fix the issue themselves.

Overall is a good book, especially for users that have no prior knowledge of CodeIgniter, is just like is presented by the authors, a book for developers that want more productivity in there work or just what to see what other tools are out there.  The book does not present full solutions like a CMS or a shopping cart, but rather what this framework has to offer.

An advanced developer can understand from this book the structure of the CodeIgniter framework, possibly to compare it to other popular frameworks, without loosing time with complex and irrelevant examples.

Factory method design pattern introduced by GoF (Gang of Four) which I’ve talked about in a previous blog, has the base idea of a method that generates objects. Most implementations are “poor”, because they use a lot of hard-coding for the factory (just like me in the previous blog).

PHP 5.3 offers the possibility of a very interesting implementation using “Late static bindings“.

The classes from which the objects will be generated are:

 1// abstract base class that will be inherited
 2abstract class Drink {
 3
 4    // ingredients
 5    protected $ingredients;
 6
 7    // public method for producing the drink
 8    abstract public function MakeDrink();
 9}
10
11// a child class for tea
12class Tea_Drink extends Drink {
13
14    // ingredients for tea
15    protected $ingredients = array('tea', 'sugar', 'mink', 'water');
16
17    // make tea
18    public function MakeDrink() {
19
20        // make tea
21    }
22}
23
24// another class for Bloody Mary
25class BloodyMary_Drink extends Drink {
26
27    // ingredients for Bloody Mary
28    protected $ingredients = array('votka', 'salt', 'tomato juice');
29
30    // make Bloody Mary
31    public function MakeDrink() {
32
33        // make BloodyMary
34
35    }
36}

The idea is to have an abstract factory class to extend as simple as possible when creating each new factory class.

PHP 5

In PHP 5 the class will look something like this:

 1// abstract Factory class
 2abstract class absFactory {
 3
 4    // name of the base class
 5    static protected $base_class = '';
 6
 7    // factory method
 8    public static function getInstance($type) {
 9
10        // name of the resulting class
11        $class_name = $type . '_' . self::$base_class;
12
13        // check if class exists
14        // here you can add an autoloader
15        if(!class_exists($class_name)) {
16            throw new Exception( 'Class ' . $class_name . ' not loaded!');
17        }
18
19        // check to see if the class inherits the base class
20        if(!is_subclass_of($class_name, self::$base_class)) {
21            throw new Exception(
22                'Class ' . $class_name . ' is not a child of ' . self::$base_class
23            );
24        }
25
26        // new object
27        return new $class_name;
28
29    }
30
31}

Because the getInstance() method is static the property will be static too.

If we try:

 1class DrinkFactory extends absFactory {
 2
 3    static protected $base_class = 'Drink';
 4}
 5
 6try {
 7
 8    $obj = DrinkFactory::getInstance('Tea');
 9
10} catch (Exception $e) {
11
12    echo $e->getMessage();
13}

The output will be:

1Class Tea_ not loaded!

Because of the “self”, we can’t just call the method using the child class because the value of $base_class will be “” and not “Drink”, we must overwrite the getInstance() method. Which is quite “complicated”.

A working version in PHP 5 will be:

 1class DrinkFactory extends absFactory {
 2
 3    public static function getInstance($type) {
 4
 5        self::$base_class = 'Drink';
 6
 7        // factory method of the base factory class
 8        parent::getInstance($type);
 9
10    }
11
12}
13
14try {
15
16    $obj = DrinkFactory::getInstance('Tea');
17
18} catch (Exception $e) {
19
20    echo $e->getMessage();
21}

But is not exactly “elegant”.

PHP 5.3

Here we have “Late static bindings”, which is basically introducing the work “static”.

The base factory class will look something like this:

 1// abstract Factory class
 2abstract class absFactory {
 3
 4    // name of the base class
 5    static protected $base_class = '';
 6
 7    // factory method
 8    public static function getInstance($type) {
 9
10        // name of the resulting class
11        $class_name = $type . '_' . static::$base_class;
12
13        // check if class exists
14        // here you can add an autoloader
15        if(!class_exists($class_name)) {
16            throw new Exception( 'Class ' . $class_name . ' not loaded!');
17        }
18
19        // check to see if the class inherits the base class
20        if(!is_subclass_of($class_name, static::$base_class)) {
21            throw new Exception(
22                'Class ' . $class_name . ' is not a child of ' . static::$base_class
23            );
24        }
25
26        // new object
27        return new $class_name;
28
29    }
30
31}

A change so small allows us to create a much “nicer” factory class:

 1class DrinkFactory extends absFactory {
 2
 3     static protected $base_class = 'Drink';
 4
 5}
 6
 7try {
 8
 9    $obj = DrinkFactory::getInstance('Tea');
10
11} catch (Exception $e) {
12
13    echo $e->getMessage();
14}

Basically in this version only the relevant property in this context is overwritten.

Another year has passed and PHP 6 is still not here…

But that’s not exactly news, is the 4-th year when this long awaited version is not released. Not for nothing is called the most awaited version.

But overall it was a good year for the community, even though we still don’t have native Unicode in a stable version now we have all other awaited features in PHP 5.3, which will probably need another few years to become used on a large scale.

Even though everyone was expecting last year for Oracle to enter in full force on medium and small database market by purchasing Sun, enlarging it’s already well established  portfolio on the enterprise market. It seems that it was not to be, CE is still analyzing the deal.

However MySQL is not what it used to be 5-6 years ago, when nobody dared to use it for enterprise products. This days MySQL is a product ready to be used in both small and large products that require a lot of scalability.

But back to the year that just ended, it was a full year, even with this economic crises.

CodeIgniter is an open-source PHP framework, build for RAD development. This framework is continuously growing in popularity, probably especially since people realized that is much easier to use an open-source framework instead of developing an internal one, but that’s another story. The CodeIgniter 1.7 book from PacktPublishing, written by Jose Argudo Blanco and David Upton is building a big picture about the CodeIgniter 1.7 framework, as an addition to the reference manual.

After all every respectable framework has an detailed reference, with usability examples, more or less comprehensible. When it comes to learning an framework (and not only), an reference is usually not the best place to start from, because is hard to get the big picture when you can only receive atomic answers. That’s why we buy books this days, to have a general image with problems and solutions. And this is where the CodeIgniter 1.7 book comes in.

Initially, when I’ve seen that the title has the version number of the analyzed framework I was a little pessimistic, because usually when you buy a book you don’t want it to be tight up to particular version, isn’t it? Well, not exactly… I had a similar issue with Zend Framework, most books use “older versions”  (ex: 1.5-1.6) and I wanted to see an approach using the new features from version 1.8 or greater. After all when you start learning something you usually want the latest version of the framework or what ever it is that you are learning, and when new features appear it will be much easier to simply look then in the reference guide since you already know the basics.

This book seams to start from the beginners level and progressively describe both basic elements as well as the most common problems the user may encounter when developing apps using the CodeIgniter framework.  The sample chapter, looks pretty well structured and easy to understand, and from the table of contents it seams to approach all the important subjects. With the hope that the rest of the book will be just as well structured (I’m actually judging a book by the cover?) and a second part to this review will follow I can’t barely wait for the book.

To be continued…