path: root/IkiWiki/Plugin/search.pm

#!/usr/bin/perl
# xapian-omega search engine plugin
package IkiWiki::Plugin::search;

use warnings;
use strict;
use IkiWiki 2.00;

sub import { #{{{
    hook(type => "checkconfig", id => "search", call => \&checkconfig);
    hook(type => "pagetemplate", id => "search", call => \&pagetemplate);
    # run last so other needsbuild hooks can modify the list
    hook(type => "needsbuild", id => "search", call => \&needsbuild,
        last => 1);
    hook(type => "filter", id => "search", call => \&filter);
    hook(type => "delete", id => "search", call => \&delete);
    hook(type => "cgi", id => "search", call => \&cgi);
} # }}}

sub checkconfig () { #{{{
    foreach my $required (qw(url cgiurl)) {
        if (! length $config{$required}) {
            error(sprintf(gettext("Must specify %s when using the search plugin"), $required));
        }
    }

    if (! exists $config{omega_cgi}) {
        $config{omega_cgi}="/usr/lib/cgi-bin/omega/omega";
    }
    
    if (! -e $config{wikistatedir}."/xapian" || $config{rebuild}) {
        writefile("omega.conf", $config{wikistatedir}."/xapian",
            "database_dir .\n".
            "template_dir ./templates\n");
        writefile("query", $config{wikistatedir}."/xapian/templates",
            IkiWiki::misctemplate(gettext("search"),
                readfile(IkiWiki::template_file("searchquery.tmpl"))));
    }
} #}}}

my $form;
sub pagetemplate (@) { #{{{
    my %params=@_;
    my $page=$params{page};
    my $template=$params{template};

    # Add search box to page header.
    if ($template->query(name => "searchform")) {
        if (! defined $form) {
            my $searchform = template("searchform.tmpl", blind_cache => 1);
            $searchform->param(searchaction => $config{cgiurl});
            $form=$searchform->output;
        }

        $template->param(searchform => $form);
    }
} #}}}

my %toindex;
sub needsbuild ($) { #{{{
    %toindex = map { pagename($_) => 1 } @{shift()};
} #}}}

my $scrubber;
sub filter (@) { #{{{
    my %params=@_;
    
    if ($params{page} eq $params{destpage} && $toindex{$params{page}}) {
        # index page
        my $db=xapiandb();
        my $doc=Search::Xapian::Document->new();
        my $title;
        if (exists $pagestate{$params{page}}{meta} &&
            exists $pagestate{$params{page}}{meta}{title}) {
            $title=$pagestate{$params{page}}{meta}{title};
        }
        else {
            $title=IkiWiki::pagetitle($params{page});
        }

        # Remove any html from text to be indexed.
        # TODO: This removes html that is in eg, a markdown pre,
        # which should not be removed, really.
        if (! defined $scrubber) {
            eval q{use HTML::Scrubber};
            if (! $@) {
                $scrubber=HTML::Scrubber->new(allow => []);
            }
        }
        my $toindex = defined $scrubber ? $scrubber->scrub($params{content}) : $params{content};
        
        # Take 512 characters for a sample, then extend it out
        # if it stopped in the middle of a word.
        my $size=512;
        my ($sample)=substr($toindex, 0, $size);
        if (length($sample) == $size) {
            my $max=length($toindex);
            my $next;
            while ($size < $max &&
                   ($next=substr($toindex, $size++, 1)) !~ /\s/) {
                $sample.=$next;
            }
        }
        $sample=~s/\n/ /g;
        
        # data used by omega
        $doc->set_data(
            "url=".urlto($params{page}, "")."\n".
            "sample=$sample\n".
            "caption=$title\n".
            "modtime=$IkiWiki::pagemtime{$params{page}}\n".
            "size=".length($params{content})."\n"
        );

        my $tg = Search::Xapian::TermGenerator->new();
        $tg->set_stemmer(new Search::Xapian::Stem("english"));
        $tg->set_document($doc);
        $tg->index_text($params{page}, 2);
        $tg->index_text($title, 2);
        $tg->index_text($toindex);

        my $pageterm=pageterm($params{page});
        $doc->add_term($pageterm);
        $db->replace_document_by_term($pageterm, $doc);
    }

    return $params{content};
} #}}}

sub delete (@) { #{{{
    my $db=xapiandb();
    foreach my $page (@_) {
        $db->delete_document_by_term(pageterm($page));
    }
} #}}}

sub cgi ($) { #{{{
    my $cgi=shift;

    if (defined $cgi->param('P')) {
        # only works for GET requests
        chdir("$config{wikistatedir}/xapian") || error("chdir: $!");
        $ENV{OMEGA_CONFIG_FILE}="./omega.conf";
        $ENV{CGIURL}=$config{cgiurl},
        exec($config{omega_cgi}) || error("$config{omega_cgi} failed: $!");
    }
} #}}}

sub pageterm ($) { #{{{
    my $page=shift;

    # TODO: check if > 255 char page names overflow term
    # length; use sha1 if so?
    return "U:".$page;
} #}}}

my $db;
sub xapiandb () { #{{{
    if (! defined $db) {
        eval q{
            use Search::Xapian;
            use Search::Xapian::WritableDatabase;
        };
        error($@) if $@;
        $db=Search::Xapian::WritableDatabase->new($config{wikistatedir}."/xapian/default",
            Search::Xapian::DB_CREATE_OR_OPEN());
    }
    return $db;
} #}}}

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