Deprecation can happen for various reasons - perhaps an API is no longer useful and has reached its end-of-life, or the refactoring of code to improve its reusability and testability obsoletes particular methods. In this article I'll share with you some key points that you should follow when deprecating APIs so you can continue to grow your code and provide fair warning to those who depend on it.

They break it up into a few different steps:

• Prepare for Refactoring
• Employ the Single Responsibility Principle
• Communicate with your Users
• Remove the Old Code

There are several reasons why a plugin may be deprecated. The symfony core framework might have included the functionality of the plugin in a recent release, or another plugin with the same functionality might be doing a better job at it. Whatever the reason, a developer is now able to mark a plugin as deprecated. This is simply done in the administration panel of the plugin.

A message will pop up when the plugin is next used to let the developers of the site know the deprecation status of the plugin - complete with a custom message.

In this final part of the series, learn about things to consider when upgrading from PHP V5.2. There are changes that break backward-compatibility and features that are deprecated in PHP V5.3 for removal in future versions. Some enhancements to existing features within PHP are also covered.

Changes included in the list are:

• Syntax changes
• Changes to functions and methods
• Extension changes
• Build changes
• Deprecated items