Starting from 3.2, a new plugin interface is added to allow one to declare any dependency on other plugin(s). This is useful for any plugin that requires another plugin to function. It is particularly useful for a plugin to detect broken dependencies that prevent if from functioning properly.

How to write a plugin that utilize this function

Let start from a real world example:

NP_PageLinkList depends on NP_BlogWithOffset to function, so we want to make sure if a user install NP_PageLinkList whithout first install NP_BlogWithOffset. With this API, Nucleus offers a way for a plugin to detect any missing dependency before it is installed.

In this case, we want to code into NP_PageLinkList to mark that it requires NP_BlogWithOffset. When the plugin is installed, the core calls a function in the plugin called getPluginDep(). This function returns a list of plugin it requires, and the core will check against all installed plugins and refuse to install the plugin if a dependency is missing.

All we have to do is added this function to NP_PageLinkList:

function getPluginDep() {
	 return array('NP_BlogWithOffset');
}

The plugin dependency check also prevents plugins from being uninstalled if other plugins have a dependancy on it.