Modern PHP

Chapter 5. Good Practices

This chapter contains an assortment of good practices that you should apply when building PHP applications. Following good practices makes your applications faster, more secure, and more stable. The PHP language is an accumulation of tools introduced piecemeal over a long period of time, and we use these tools to apply good practices. Tools change with the passage of time as newer and better solutions are introduced in newer PHP versions. Unfortunately, the PHP language still contains outdated tools from its past, and it’s possible to build slow and insecure applications with these outmoded tools if you’re not careful. The trick is knowing which tools to use and which to ignore. That’s what this chapter is all about.

I’m not preaching “best practices” from atop an academic ivory tower. This chapter contains good and practical advice that I use every day in all of my own projects. You can immediately apply this knowledge to your own projects.

Note

Good practices demonstrated in this chapter have always been possible with past and present PHP versions. However, how you implement these practices changes as the PHP language evolves. Newer PHP versions introduce tools that make it easier to apply good practices. This chapter demonstrates how to apply good practices with the latest tools in PHP 5.3+.

Sanitize, Validate, and Escape

Fox Mulder is correct—trust no one. Never trust any data that originates from a source not under your direct control. A few external ...