The two other video tutorials he's posted are:

• an introduction to encryption
• about programming paradigms

If you like the videos, leave him feedback on what you'd like to see in future videos.

Even so not every PHP Developers knows WHY we don't use references pretty much every core function and every somewhat modern framework avoids them so people adapted this best practice. The leftovers in the PHP core, like sort() or str_replace(), are exceptions to the rule. So if the common consensus is, or at least 'should be', that we should not use references then maybe we should start looking for places where they hurt and how we could fix them?

He talks about prepared statements and one thing he sees that makes it a "hard sell" to developers needing a good way to query their databases. He points out the difference in code required between the normal MySQL calls and mysqli (hint: it's more) and shows how to use an abstraction layer to make things a bit easier. He points out the downfalls of using this approach, mainly the performance hit you get (from using his fetchAll method).

In this second part of the three part column on the new garbage collecting mechanism in PHP 5.3, we'll dive into a solution to the problem with circular references. If we look quickly back, we found that by using code like the [first example], an in-request memory leak is created.

He goes on to briefly describe the synchronous algorithm (including a few more helpful graphs to show the flow) and how that has worked its way into the PHP garbage collection methods. He also points out that this collection can be turned off and on via the gc_enable and gc_disable functions. Keep an eye out for the next part of the series where he gets into more detail on how this is all integrated into PHP.

Now there is one use case which leads to an, at first, unexpected behavior which I didn't see as a real live issue when I stumbled over it at first, but then there were a few bug reports about it and recently a friend asked me about it ... so here it goes.

He show a code snippet of looping over an array with two foreaches and a print_r that shows the bug - the array changed from the original for no clearly apparent reason. To understand why this happens, he goes into detail on how variables are handled - complete with graphs.

Last year I spoke at eight conferences and attended a few more multiple times at most of them I found myself in discussions about references and PHP as many users seem to have wrong understandings about them. Before going to deep into the subject let's start with a quick reminder what references are and clear some confusion about objects which are "passed by reference."

He re-introduces referenced variables and scratches the surface about the confusion they can cause, not only on the user level but also in the internals of the language, and can lead to some unexpected results. He also mentions the "always passed by reference" idea that several PHPers have about PHP5 objects and why it's not entirely correct. He finishes off the post with a look at returning referenced parameters and how it can lead to bad application design.

• Unvalidated Parameters
• Broken Access Control
• Broken Account and Session Management
• Cross-Site Scripting (XSS) Flaws
• Buffer Overflows
• Command Injection Flaws
• Error Handling Problems
• Insecure Use of Cryptography
• Remote Administration Flaws
• Web and Application Server Misconfiguration

Each item on the list has a bit of detail (and sometimes some code) to help point out the problem. Some of them even have references to external sources and packages to help you solve the problems.

Reading planet-debian and Apache (from Sven and David), I catched two posts about clones and references in php4 and php5. I do not think it is worth to explain again everything here as Sara wrote a very good post already, check it out here.

He mentions his annoyance with articles/posts like these and the impact that it has on PHP as well as the person posting.

I wonder when the OS community in general will be mature enough to stop bitching at each other. And that's valid for PHP developers, gnome-kde and other well established wars.

Following on from my posts "Object-Oriented Concepts" and "Object-Oriented Javascript", I'm going to take a look at OOP in PHP.

In "Part 1: Definition" we took a look at defining objects and classes in PHP. In part 2 I'm going to look at the most important part of any object-oriented system - the relationships.

They look at inheritance, association, aggregation, and references. Code examples are sprinkled liberally to help illustrate the points.

There's also a comment made about the Call for Papers for php|architect's next conference later in the year.

From Davey:

Mine are:

• Sams Teach Yourself MySQL in 10 Minutes
• JavaScript: The Definitive Guide
• Essential PHP Security
• XSLT
• PHP|Architect's Guide to PHP Design Patterns
• The latest issue of php|architect

And Firman's:

• Wrox Professional CSS Cascading Style Sheets for Web Design
• Design Patterns: Elements of Reusable Object-Oriented Software (Addison-Wesley Professional Computing Series)
• Manning Ajax in Action
• PHP|Architect issues
• PHP Manual
• PEAR Manual

What kind of reference materials do you use? What books are on your desk that never seem to collect dust because is seems like they're always in use? Do you have one of the giant PHP posters on your wall that SitePoint was offering? Post your comments below!]]> Tue, 15 Nov 2005 06:10:09 -0600