CHAPTER 12 – DEPENDENCIES 2

Optional Dependencies Use optional dependencies (<dep optional="yes" ...> in package.xml) for pack- ages or extensions that would add functionality to your package without being absolutely required. For example, if you have a file-handling package, you could use an optional dependency to the zlib extension and handle .gz files only if the zlib extension is available.  

Some Examples This example shows a package.xml snippet with dependency definitions taken from the DB package: <deps> <dep type="php" rel="ge" version="4.2.0" /> <dep type="pkg" rel="ge" version="1.0b1">PEAR</dep> </deps> DB requires PHP 4.2.0 or newer, as well as release 1.0b1 or newer of the PEAR package. Here is a an example demonstrating optional dependencies: <deps> <dep type="php" rel="ge" version="5.0.0" /> <dep type="pkg" optional="yes">Cache_Lite</dep> <dep type="ext">zlib</dep> </deps> This package requires PHP 5.0.0 or newer with zlib loaded, and offers extra features if the Cache_Lite package is installed.