DevShed continues their series on the Visitor objects in PHP5 with this second part, looking at expanding the "application range" of the objects.

Well, at this stage I'm assuming that creating visitor objects with PHP isn't a strange concept to you any longer, therefore I'll continue this journey by developing some additional -yet useful- examples on how to build up and implement visitors with PHP 5. The main purpose of this is simply reaffirming the concepts deployed in the first tutorial, so you can have a solid background for including your own visitor classes inside your PHP applications.

They start off by creating a new abstract class to use in this part, a User class with plenty of properties and methods. Next up, they make a class extending this base, abstract class to make a SoftwareUser that will accept visitor objects. They then use this interface and create a Visitor class to make the calls, showing a code example of them playing nicely together.

On BarelyFitz Designs, there's a handy tutorial that's been posted to help developers out there combine the powers of PHP and CSS to form a sort of color management system for their site.

While many web sites use powerful programming environments to create HTML, these same tools are usually ignored when it comes to creating Cascading Style Sheets (CSS). This article describes how to take control of your colors in CSS using PHP. You will learn how to:

• Centralize your color definitions using variables.
• Separate presentation and content by referring to colors using abstract names such as base and highlight.
• Automatically generate a color gradient from a single base color:
• Automatically adjust the contrast of foreground colors so they can viewed on top of your background colors

They follow the steps to making a CSS file with PHP - generate the header and output the CSS - as well as examples of its usage. They create a range of colors based around a central one, five levels in either direction. The file they've created to accomplish this is also available for download.

DevShed has the second part of their "Building a PHP5 Form Processor" series posted today - Coding the Form Validator Module. It looks at how to construct a set of functions that will check the data inputted to ensure it exists and correct/valid.

In this second part of a three-part series, we take up the topic of server-side validation. By the time you finish this article, you'll have the general guidelines for how to build a form validating class. You'll use some PHP built-in introspection functions, along with regular expressions, to assist you in building this class.

They create several functions, including validateEmpty, validateInteger, validateNumber, validateRange, and validateEmail. Each one (obviously) serves their own purpose, and some are more complex that others (validating an integer versus a valid email address), but they walk you through each, showing you plenty of code and explainations along the way...