[wp-hackers] Plugin interference

[gbellucci]

Recently, I've provided help to users when my plugin doesn't work
after activating it. The very first thing I suggest to them:
Deactivate all plugins, activate my plugin and if it begins working -
start activating other plugins until it stops again.

When they tell me which ones cause the plugin to stop working I start
looking at the code for those plugins. In all cases, the problem is
caused by plugin 'X' registering with the wp_admin_head() hook or by
registering some other call that causes Word Press to inject plugin
'X' java scripts and their java script dependencies for every single
backend page - this includes admin pages that are created for and used
by other plugins.

Frankly, this is just... bad behavior. It isn't difficult to determine
which backend page is about to be presented to the user. If your
plugin interacts with that page - great! If not, then don't create an
environment in which your plugin possibly renders another plugin
unusable.