Markus Wolff takes a look at a part of the setup surrounding the Zend Framework in this blog post today - the Framework's CLA.

Contributors to the Zend Framework must first sign a Contributor License Agreement (CLA) before they're allowed to commit anything. This is claimed to make the Zend Framework "IP clean", so big corporations have no problem adopting it.

I've never believed in this proclaimed need of being "IP clean". Maybe that's because stealing someone's proprietary code never came to mind - am I just to good a person? However, in a world where in certain strange countries (I won't drop any names here) you can actually patent software - or worse, ideas - it is increasingly difficult to write a single line of code that you can be sure of not violating anyone else's so-called intellectual property.

He quotes from the CLA's FAQ on the Framework site about the protection this CLA offers to both the Framework and to the developers that contribute to it.

His rebuttal is one of "how can this be enforced?", which, of course, he realizes is just not possible. He casts a "marketing first" light on the CLA, suggesting that it's just a way to help sell it to corporations.

DevShed is continuing their "Enforcing Object Types in PHP" series with this new tutorial today. This time, they're focusing mor eon the use of the instanceof operator in PHP5.

This three-part series goes through the basic concepts of object type enforcement in PHP 4/PHP 5. It explores different approaches for checking types of objects to help you avoid possible code contamination when objects of incorrect type are inputted within PHP classes.

The end result of this article hopefully will help you to expand your grounding in how to implement object type enforcement in PHP 5, by developing some illustrative, object-oriented examples.

They start with a look at how not to do the object checking but provide a solution to the situation with the help of the instanceof operator. They explain its usage in the context of the widget class they've created, and show you how it can be integrated easily to simplify object validation.