[wp-hackers] Restrict plugin load to certain pages?

[John Blackbourn]

On 1 July 2013 10:02, David Anderson <david at wordshell.net> wrote:
> Looking at the WP core code, my only option to achieve this seems to be to
> be (via an mu-plugin, since a plugin would present a Catch-22) to hook
> get_option, detect the option 'active_plugins', and remove the offending
> plugin depending on the contents of _SERVER['REQUEST_URI'] and is_admin() (I
> don't want to disable anything admin-side).

You're approaching this from the wrong angle. Rather than not loading
the plugin at all when it's not necessary, you should only load the
required parts of your plugin when necessary. If your mu-plugin is
able to detect the correct condition to determine when your forum
plugin should or should not be loaded, then it can instead be done
within the forum plugin itself.

If your plugin is split up into separate files effectively then you
should only load minimal code on every page load, detect if the rest
of the plugin needs to be loaded (eg. by inspecting the URL as you
state) and then loading its other files when necessary. There's no
need for a separate plugin, and certainly no need for a nasty hack
like filtering the value of the active plugins option.

This can be as simple as (pseudo-code):

if ( url_contains( 'forum' ) )
    include 'forum-code.php';

Lots of plugins use similar code for only loading files in the admin
are. It's pretty simple stuff.

if ( is_admin() )
    include 'admin-code.php';

Additionally, if your plugin makes good use of object oriented
programming and is split into multiple classes then you can use
autoloading.

John