Now that you know what will be treated in this fourth chapter of the series, it's time to learn how to declare and implement public and protected methods with PHP 5 classes. Of course, as always I'm going to address this useful topic by using a hands-on approach, which means that there's a bunch of code samples ahead, waiting patiently for you.

They talk about calling methods globally first and then move into the keyword restrictions. They show the difference between a public method/variable and a protected one, including how to get at the protected members from a child class.

In this last chapter of the series, I'm going to teach you how to handle the child nodes of an XML document by way of two simple methods, called hasChildNode() and removeChild() respectively. So let's not waste any more time in preliminaries and learn how to use them in a helpful way.

They review some of the concepts mentioned previously before moving ahead to the use of the hasChildNodes and removeChild methods to check for children and get rid of only certain ones.

PHP has a function serialize, which can create a hash from any type of variable, scalars, array, but objects as well. Using the unserialize function, PHP can recreate the variable from the serialized hashed. If we look at how an object is serialized, we see only the properties and the class name are stored.

His method allows for class manipulation via changes to the serialized class information (like changing the value of the name parameter). His "casttoclass()" function makes changing this value simple.

In the last article, "Hello PHP-GTK", we looked at what it takes to create a simple application. At the end, we were left with a PHP-GTK implementation of "Hello World". The application was very simple. Too simple. All it did was display one line of text in a window. In this article we will expand on the previous article by adding more content to the window. Along the way we will look at how parents and children interact and what it takes to make children behave properly.

He starts by explaining the parent child relationship between the base window and other children (spawned) windows, mentioning the GtkWindow and GtkObject widgets. With windows down, he moves on to "boxes", seperation areas inside the windows to help organize the content (including ways to frame them in). And, to wrap it all up, a look at GtkTable, a widget that helps you create a nicely laid out table inside of your window (simpler than several boxes).