[[!template id=plugin name=underlay author="[[Simon_McVittie|smcv]]"]]
[[!tag type/useful]]

This plugin adds an `add_underlays` option to the `.setup` file.
Its value is a list of underlay directories whose content is added to the wiki.

Multiple underlays are normally set up automatically by other plugins (for
instance, the smiley images used by [[plugins/smileys]]), but they can also be
used as a way to pull in external files that you don't want in revision control,
like photos or software releases.

Directories in `add_underlays` should usually be absolute. If relative, they're
interpreted as relative to the parent directory of the basewiki underlay, which
is probably not particularly useful in this context.

    #!/usr/bin/perl
    package IkiWiki::Plugin::underlay;
    # Copyright © 2008 Simon McVittie <http://smcv.pseudorandom.co.uk/>
    # Licensed under the GNU GPL, version 2, or any later version published by the
    # Free Software Foundation

    use warnings;
    use strict;
    use IkiWiki 2.00;

    sub import {
    	hook(type => "getsetup", id => "underlay",  call => \&getsetup);
    	hook(type => "checkconfig", id => "underlay", call => \&checkconfig);
    }

    sub getsetup () {
    	return
    		plugin => {
    			safe => 0,
    			rebuild => undef,
    		},
    		add_underlays => {
    			type => "string",
    			default => [],
    			description => "extra underlay directories to add",
    			advanced => 1,
    			safe => 0,
    			rebuild => 1,
    		},
    }

    sub checkconfig () {
    	return unless exists $config{add_underlays};

    	foreach my $dir (@{$config{add_underlays}}) {
    		add_underlay($dir);
    	}
    }

    1;