]> sipb.mit.edu Git - ikiwiki.git/blobdiff - IkiWiki/Plugin/comments.pm
factor out a userpage function
[ikiwiki.git] / IkiWiki / Plugin / comments.pm
index cb5a517a107ea94007f00ae77436d76f69ddbdae..caed0d58c5e05fedc70a7a480a5247e728c83b69 100644 (file)
@@ -7,7 +7,7 @@ package IkiWiki::Plugin::comments;
 
 use warnings;
 use strict;
-use IkiWiki 2.00;
+use IkiWiki 3.00;
 use Encode;
 use POSIX qw(strftime);
 
@@ -16,15 +16,20 @@ use constant POST_COMMENT => "Post comment";
 use constant CANCEL => "Cancel";
 
 my $postcomment;
+my %commentstate;
 
 sub import {
        hook(type => "checkconfig", id => 'comments',  call => \&checkconfig);
        hook(type => "getsetup", id => 'comments',  call => \&getsetup);
+       hook(type => "preprocess", id => 'comment', call => \&preprocess);
+       # here for backwards compatability with old comments
        hook(type => "preprocess", id => '_comment', call => \&preprocess);
        hook(type => "sessioncgi", id => 'comment', call => \&sessioncgi);
        hook(type => "htmlize", id => "_comment", call => \&htmlize);
        hook(type => "pagetemplate", id => "comments", call => \&pagetemplate);
-       hook(type => "cgi", id => "comments", call => \&linkcgi);
+       hook(type => "formbuilder_setup", id => "comments", call => \&formbuilder_setup);
+       # Load goto to fix up user page links for logged-in commenters
+       IkiWiki::loadplugin("goto");
        IkiWiki::loadplugin("inline");
 }
 
@@ -36,7 +41,7 @@ sub getsetup () {
                },
                comments_pagespec => {
                        type => 'pagespec',
-                       example => 'blog/* and *!/Discussion',
+                       example => 'blog/* and !*/Discussion',
                        description => 'PageSpec of pages where comments are allowed',
                        link => 'ikiwiki/PageSpec',
                        safe => 1,
@@ -133,8 +138,8 @@ sub preprocess {
        }
 
        # no need to bother with htmlize if it's just HTML
-       $content = IkiWiki::htmlize($page, $params{destpage}, $format,
-               $content) if defined $format;
+       $content = IkiWiki::htmlize($page, $params{destpage}, $format, $content)
+               if defined $format;
 
        IkiWiki::run_hooks(sanitize => sub {
                $content = shift->(
@@ -151,11 +156,26 @@ sub preprocess {
        my $commentip;
        my $commentauthor;
        my $commentauthorurl;
-
+       my $commentopenid;
        if (defined $params{username}) {
                $commentuser = $params{username};
-               ($commentauthorurl, $commentauthor) =
-                       linkuser($params{username});
+
+               my $oiduser = eval { IkiWiki::openiduser($commentuser) };
+
+               if (defined $oiduser) {
+                       # looks like an OpenID
+                       $commentauthorurl = $commentuser;
+                       $commentauthor = $oiduser;
+                       $commentopenid = $commentuser;
+               }
+               else {
+                       $commentauthorurl = IkiWiki::cgiurl(
+                               do => 'goto',
+                               page => IkiWiki::userpage($commentuser)
+                       );
+
+                       $commentauthor = $commentuser;
+               }
        }
        else {
                if (defined $params{ip}) {
@@ -164,10 +184,11 @@ sub preprocess {
                $commentauthor = gettext("Anonymous");
        }
 
-       $pagestate{$page}{comments}{commentuser} = $commentuser;
-       $pagestate{$page}{comments}{commentip} = $commentip;
-       $pagestate{$page}{comments}{commentauthor} = $commentauthor;
-       $pagestate{$page}{comments}{commentauthorurl} = $commentauthorurl;
+       $commentstate{$page}{commentuser} = $commentuser;
+       $commentstate{$page}{commentopenid} = $commentopenid;
+       $commentstate{$page}{commentip} = $commentip;
+       $commentstate{$page}{commentauthor} = $commentauthor;
+       $commentstate{$page}{commentauthorurl} = $commentauthorurl;
        if (! defined $pagestate{$page}{meta}{author}) {
                $pagestate{$page}{meta}{author} = $commentauthor;
        }
@@ -180,8 +201,17 @@ sub preprocess {
                        $pagestate{$page}{meta}{author} = $params{claimedauthor};
                }
 
-               if (defined $params{url} and safeurl($params{url})) {
-                       $pagestate{$page}{meta}{authorurl} = $params{url};
+               if (defined $params{url}) {
+                       my $url=$params{url};
+
+                       eval q{use URI::Heuristic}; 
+                       if (! $@) {
+                               $url=URI::Heuristic::uf_uristr($url);
+                       }
+
+                       if (safeurl($url)) {
+                               $pagestate{$page}{meta}{authorurl} = $url;
+                       }
                }
        }
        else {
@@ -193,12 +223,10 @@ sub preprocess {
                $pagestate{$page}{meta}{title} = $params{subject};
        }
 
-       my $baseurl = urlto($params{destpage}, undef, 1);
-       my $anchor = "";
-       if ($params{page} =~ m/\/(\Q$config{comments_pagename}\E\d+)$/) {
-               $anchor = $1;
+       if ($params{page} =~ m/\/\Q$config{comments_pagename}\E\d+_/) {
+               $pagestate{$page}{meta}{permalink} = urlto(IkiWiki::dirname($params{page}), undef, 1).
+                       "#".page_to_id($params{page});
        }
-       $pagestate{$page}{meta}{permalink} = "${baseurl}#${anchor}";
 
        eval q{use Date::Parse};
        if (! $@) {
@@ -206,69 +234,27 @@ sub preprocess {
                $IkiWiki::pagectime{$page} = $time if defined $time;
        }
 
-       # FIXME: hard-coded HTML (although it's just to set an ID)
-       return "<div id=\"$anchor\">$content</div>" if $anchor;
        return $content;
 }
 
-# This is exactly the same as recentchanges_link :-(
-sub linkcgi ($) {
+sub sessioncgi ($$) {
        my $cgi=shift;
-       if (defined $cgi->param('do') && $cgi->param('do') eq "commenter") {
-
-               my $page=decode_utf8($cgi->param("page"));
-               if (! defined $page) {
-                       error("missing page parameter");
-               }
-
-               IkiWiki::loadindex();
-
-               my $link=bestlink("", $page);
-               if (! length $link) {
-                       print "Content-type: text/html\n\n";
-                       print IkiWiki::misctemplate(gettext(gettext("missing page")),
-                               "<p>".
-                               sprintf(gettext("The page %s does not exist."),
-                                       htmllink("", "", $page)).
-                               "</p>");
-               }
-               else {
-                       IkiWiki::redirect($cgi, urlto($link, undef, 1));
-               }
-
-               exit;
-       }
-}
-
-# FIXME: basically the same logic as recentchanges
-# returns (author URL, pretty-printed version)
-sub linkuser ($) {
-       my $user = shift;
-       my $oiduser = eval { IkiWiki::openiduser($user) };
+       my $session=shift;
 
-       if (defined $oiduser) {
-               return ($user, $oiduser);
+       my $do = $cgi->param('do');
+       if ($do eq 'comment') {
+               editcomment($cgi, $session);
        }
-       # FIXME: it'd be good to avoid having such a link for anonymous
-       # posts
-       else {
-               return (IkiWiki::cgiurl(
-                               do => 'commenter',
-                               page => (length $config{userdir}
-                                       ? "$config{userdir}/$user"
-                                       : "$user")
-                       ), $user);
+       elsif ($do eq 'commentmoderation') {
+               commentmoderation($cgi, $session);
        }
 }
 
 # Mostly cargo-culted from IkiWiki::plugin::editpage
-sub sessioncgi ($$) {
+sub editcomment ($$) {
        my $cgi=shift;
        my $session=shift;
 
-       my $do = $cgi->param('do');
-       return unless $do eq 'comment';
-
        IkiWiki::decode_cgi_utf8($cgi);
 
        eval q{use CGI::FormBuilder};
@@ -285,9 +271,7 @@ sub sessioncgi ($$) {
                action => $config{cgiurl},
                header => 0,
                table => 0,
-               template => scalar IkiWiki::template_params('comments_form.tmpl'),
-               # wtf does this do in editpage?
-               wikiname => $config{wikiname},
+               template => scalar IkiWiki::template_params('editcomment.tmpl'),
        );
 
        IkiWiki::decode_form_utf8($form);
@@ -304,10 +288,15 @@ sub sessioncgi ($$) {
        else {
                $type = $config{default_pageext};
        }
+
+
        my @page_types;
        if (exists $IkiWiki::hooks{htmlize}) {
-               @page_types = grep { ! /^_/ } keys %{$IkiWiki::hooks{htmlize}};
+               foreach my $key (grep { !/^_/ } keys %{$IkiWiki::hooks{htmlize}}) {
+                       push @page_types, [$key, $IkiWiki::hooks{htmlize}{$key}{longname} || $key];
+               }
        }
+       @page_types=sort @page_types;
 
        $form->field(name => 'do', type => 'hidden');
        $form->field(name => 'sid', type => 'hidden', value => $session->id,
@@ -334,6 +323,13 @@ sub sessioncgi ($$) {
                        force => 1);
        }
 
+       if (! defined $session->param('name')) {
+               # Make signinurl work and return here.
+               $form->tmpl_param(signinurl => IkiWiki::cgiurl(do => 'signin'));
+               $session->param(postsignin => $ENV{QUERY_STRING});
+               IkiWiki::cgi_savesession($session);
+       }
+
        # The untaint is OK (as in editpage) because we're about to pass
        # it to file_pruned anyway
        my $page = $form->field('page');
@@ -343,8 +339,6 @@ sub sessioncgi ($$) {
                error(gettext("bad page name"));
        }
 
-       # FIXME: is this right? Or should we be using the candidate subpage
-       # (whatever that might mean) as the base URL?
        my $baseurl = urlto($page, undef, 1);
 
        $form->title(sprintf(gettext("commenting on %s"),
@@ -382,16 +376,7 @@ sub sessioncgi ($$) {
        IkiWiki::check_canedit($page, $cgi, $session);
        $postcomment=0;
 
-       # FIXME: rather a simplistic way to make the comments...
-       my $i = 0;
-       my $file;
-       my $location;
-       do {
-               $i++;
-               $location = "$page/$config{comments_pagename}$i";
-       } while (-e "$config{srcdir}/$location._comment");
-
-       my $content = "[[!_comment format=$type\n";
+       my $content = "[[!comment format=$type\n";
 
        # FIXME: handling of double quotes probably wrong?
        if (defined $session->param('name')) {
@@ -408,22 +393,25 @@ sub sessioncgi ($$) {
 
        if ($config{comments_allowauthor}) {
                my $author = $form->field('author');
-               if (length $author) {
+               if (defined $author && length $author) {
                        $author =~ s/"/&quot;/g;
                        $content .= " claimedauthor=\"$author\"\n";
                }
                my $url = $form->field('url');
-               if (length $url) {
+               if (defined $url && length $url) {
                        $url =~ s/"/&quot;/g;
                        $content .= " url=\"$url\"\n";
                }
        }
 
        my $subject = $form->field('subject');
-       if (length $subject) {
+       if (defined $subject && length $subject) {
                $subject =~ s/"/&quot;/g;
-               $content .= " subject=\"$subject\"\n";
        }
+       else {
+               $subject = "comment ".(num_comments($page, $config{srcdir}) + 1);
+       }
+       $content .= " subject=\"$subject\"\n";
 
        $content .= " date=\"" . decode_utf8(strftime('%Y-%m-%dT%H:%M:%SZ', gmtime)) . "\"\n";
 
@@ -433,6 +421,8 @@ sub sessioncgi ($$) {
        $editcontent =~ s/"/\\"/g;
        $content .= " content=\"\"\"\n$editcontent\n\"\"\"]]\n";
 
+       my $location=unique_comment_location($page, $content, $config{srcdir});
+
        # This is essentially a simplified version of editpage:
        # - the user does not control the page that's created, only the parent
        # - it's always a create operation, never an edit
@@ -440,35 +430,49 @@ sub sessioncgi ($$) {
        # - this means that if they do, rocks fall and everyone dies
 
        if ($form->submitted eq PREVIEW) {
-               my $preview = IkiWiki::htmlize($location, $page, '_comment',
-                               IkiWiki::linkify($page, $page,
-                                       IkiWiki::preprocess($page, $page,
-                                               IkiWiki::filter($location,
-                                                       $page, $content),
-                                               0, 1)));
+               my $preview=previewcomment($content, $location, $page, time);
                IkiWiki::run_hooks(format => sub {
-                               $preview = shift->(page => $page,
-                                       content => $preview);
-                       });
-
-               my $template = template("comments_display.tmpl");
-               $template->param(content => $preview);
-               $template->param(title => $form->field('subject'));
-               $template->param(ctime => displaytime(time));
-
-               $form->tmpl_param(page_preview => $template->output);
+                       $preview = shift->(page => $page,
+                               content => $preview);
+               });
+               $form->tmpl_param(page_preview => $preview);
        }
        else {
                $form->tmpl_param(page_preview => "");
        }
 
        if ($form->submitted eq POST_COMMENT && $form->validate) {
-               my $file = "$location._comment";
-
                IkiWiki::checksessionexpiry($cgi, $session);
+               
+               $postcomment=1;
+               my $ok=IkiWiki::check_content(content => $form->field('editcontent'),
+                       subject => $form->field('subject'),
+                       $config{comments_allowauthor} ? (
+                               author => $form->field('author'),
+                               url => $form->field('url'),
+                       ) : (),
+                       page => $location,
+                       cgi => $cgi,
+                       session => $session,
+                       nonfatal => 1,
+               );
+               $postcomment=0;
+
+               if (! $ok) {
+                       my $penddir=$config{wikistatedir}."/comments_pending";
+                       $location=unique_comment_location($page, $content, $penddir);
+                       writefile("$location._comment", $penddir, $content);
+                       IkiWiki::printheader($session);
+                       print IkiWiki::misctemplate(gettext(gettext("comment stored for moderation")),
+                               "<p>".
+                               gettext("Your comment will be posted after moderator review").
+                               "</p>");
+                       exit;
+               }
 
                # FIXME: could probably do some sort of graceful retry
                # on error? Would require significant unwinding though
+               my $file = "$location._comment";
                writefile($file, $config{srcdir}, $content);
 
                my $conflict;
@@ -499,9 +503,12 @@ sub sessioncgi ($$) {
                # breaks it or something
                error($conflict) if defined $conflict;
 
-               # Bounce back to where we were, but defeat broken caches
-               my $anticache = "?updated=$page/$config{comments_pagename}$i";
-               IkiWiki::redirect($cgi, urlto($page, undef, 1).$anticache);
+               # Jump to the new comment on the page.
+               # The trailing question mark tries to avoid broken
+               # caches and get the most recent version of the page.
+               IkiWiki::redirect($cgi, urlto($page, undef, 1).
+                       "?updated#".page_to_id($location));
+
        }
        else {
                IkiWiki::showform ($form, \@buttons, $session, $cgi,
@@ -511,10 +518,178 @@ sub sessioncgi ($$) {
        exit;
 }
 
+sub commentmoderation ($$) {
+       my $cgi=shift;
+       my $session=shift;
+
+       IkiWiki::needsignin($cgi, $session);
+       if (! IkiWiki::is_admin($session->param("name"))) {
+               error(gettext("you are not logged in as an admin"));
+       }
+
+       IkiWiki::decode_cgi_utf8($cgi);
+       
+       if (defined $cgi->param('sid')) {
+               IkiWiki::checksessionexpiry($cgi, $session);
+
+               my $rejectalldefer=$cgi->param('rejectalldefer');
+
+               my %vars=$cgi->Vars;
+               my $added=0;
+               foreach my $id (keys %vars) {
+                       if ($id =~ /(.*)\Q._comment\E$/) {
+                               my $action=$cgi->param($id);
+                               next if $action eq 'Defer' && ! $rejectalldefer;
+
+                               # Make sure that the id is of a legal
+                               # pending comment before untainting.
+                               my ($f)= $id =~ /$config{wiki_file_regexp}/;
+                               if (! defined $f || ! length $f ||
+                                   IkiWiki::file_pruned($f, $config{srcdir})) {
+                                       error("illegal file");
+                               }
+
+                               my $page=IkiWiki::possibly_foolish_untaint(IkiWiki::dirname($1));
+                               my $file="$config{wikistatedir}/comments_pending/".
+                                       IkiWiki::possibly_foolish_untaint($id);
+
+                               if ($action eq 'Accept') {
+                                       my $content=eval { readfile($file) };
+                                       next if $@; # file vanished since form was displayed
+                                       my $dest=unique_comment_location($page, $content, $config{srcdir})."._comment";
+                                       writefile($dest, $config{srcdir}, $content);
+                                       if ($config{rcs} and $config{comments_commit}) {
+                                               IkiWiki::rcs_add($dest);
+                                       }
+                                       $added++;
+                               }
+
+                               # This removes empty subdirs, so the
+                               # .ikiwiki/comments_pending dir will
+                               # go away when all are moderated.
+                               require IkiWiki::Render;
+                               IkiWiki::prune($file);
+                       }
+               }
+
+               if ($added) {
+                       my $conflict;
+                       if ($config{rcs} and $config{comments_commit}) {
+                               my $message = gettext("Comment moderation");
+                               IkiWiki::disable_commit_hook();
+                               $conflict=IkiWiki::rcs_commit_staged($message,
+                                       $session->param('name'), $ENV{REMOTE_ADDR});
+                               IkiWiki::enable_commit_hook();
+                               IkiWiki::rcs_update();
+                       }
+               
+                       # Now we need a refresh
+                       require IkiWiki::Render;
+                       IkiWiki::refresh();
+                       IkiWiki::saveindex();
+               
+                       error($conflict) if defined $conflict;
+               }
+       }
+
+       my @comments=map {
+               my ($id, $ctime)=@{$_};
+               my $file="$config{wikistatedir}/comments_pending/$id";
+               my $content=readfile($file);
+               my $preview=previewcomment($content, $id,
+                       IkiWiki::dirname($_), $ctime);
+               {
+                       id => $id,
+                       view => $preview,
+               } 
+       } sort { $b->[1] <=> $a->[1] } comments_pending();
+
+       my $template=template("commentmoderation.tmpl");
+       $template->param(
+               sid => $session->id,
+               comments => \@comments,
+       );
+       IkiWiki::printheader($session);
+       my $out=$template->output;
+       IkiWiki::run_hooks(format => sub {
+               $out = shift->(page => "", content => $out);
+       });
+       print IkiWiki::misctemplate(gettext("comment moderation"), $out);
+       exit;
+}
+
+sub formbuilder_setup (@) {
+       my %params=@_;
+
+       my $form=$params{form};
+       if ($form->title eq "preferences" &&
+           IkiWiki::is_admin($params{session}->param("name"))) {
+               push @{$params{buttons}}, "Comment Moderation";
+               if ($form->submitted && $form->submitted eq "Comment Moderation") {
+                       commentmoderation($params{cgi}, $params{session});
+               }
+       }
+}
+
+sub comments_pending () {
+       my $dir="$config{wikistatedir}/comments_pending/";
+       return unless -d $dir;
+
+       my @ret;
+       eval q{use File::Find};
+       error($@) if $@;
+       find({
+               no_chdir => 1,
+               wanted => sub {
+                       $_=decode_utf8($_);
+                       if (IkiWiki::file_pruned($_, $dir)) {
+                               $File::Find::prune=1;
+                       }
+                       elsif (! -l $_ && ! -d _) {
+                               $File::Find::prune=0;
+                               my ($f)=/$config{wiki_file_regexp}/; # untaint
+                               if (defined $f && $f =~ /\Q._comment\E$/) {
+                                       my $ctime=(stat($f))[10];
+                                       $f=~s/^\Q$dir\E\/?//;
+                                        push @ret, [$f, $ctime];
+                               }
+                       }
+               }
+       }, $dir);
+
+       return @ret;
+}
+
+sub previewcomment ($$$) {
+       my $content=shift;
+       my $location=shift;
+       my $page=shift;
+       my $time=shift;
+
+       my $preview = IkiWiki::htmlize($location, $page, '_comment',
+                       IkiWiki::linkify($location, $page,
+                       IkiWiki::preprocess($location, $page,
+                       IkiWiki::filter($location, $page, $content), 0, 1)));
+
+       my $template = template("comment.tmpl");
+       $template->param(content => $preview);
+       $template->param(ctime => displaytime($time));
+
+       IkiWiki::run_hooks(pagetemplate => sub {
+               shift->(page => $location,
+                       destpage => $page,
+                       template => $template);
+       });
+
+       $template->param(have_actions => 0);
+
+       return $template->output;
+}
+
 sub commentsshown ($) {
        my $page=shift;
 
-       return ! pagespec_match($page, "*/$config{comments_pagename}*",
+       return ! pagespec_match($page, "internal(*/$config{comments_pagename}*)",
                                location => $page) &&
               pagespec_match($page, $config{comments_pagespec},
                              location => $page);
@@ -534,15 +709,18 @@ sub pagetemplate (@) {
 
        my $page = $params{page};
        my $template = $params{template};
+       my $shown = ($template->query(name => 'commentslink') ||
+                    $template->query(name => 'commentsurl') ||
+                    $template->query(name => 'atomcommentsurl') ||
+                    $template->query(name => 'comments')) &&
+                   commentsshown($page);
 
        if ($template->query(name => 'comments')) {
-               my $shown = commentsshown($page);
-
                my $comments = undef;
                if ($shown) {
                        $comments = IkiWiki::preprocess_inline(
                                pages => "internal($page/$config{comments_pagename}*)",
-                               template => 'comments_display',
+                               template => 'comment',
                                show => 0,
                                reverse => 'yes',
                                page => $page,
@@ -557,9 +735,25 @@ sub pagetemplate (@) {
                }
 
                if ($shown && commentsopen($page)) {
-                       my $commenturl = IkiWiki::cgiurl(do => 'comment',
+                       my $addcommenturl = IkiWiki::cgiurl(do => 'comment',
                                page => $page);
-                       $template->param(commenturl => $commenturl);
+                       $template->param(addcommenturl => $addcommenturl);
+               }
+       }
+
+       if ($template->query(name => 'commentsurl')) {
+               if ($shown) {
+                       $template->param(commentsurl =>
+                               urlto($page, undef, 1).'#comments');
+               }
+       }
+
+       if ($template->query(name => 'atomcommentsurl') && $config{usedirs}) {
+               if ($shown) {
+                       # This will 404 until there are some comments, but I
+                       # think that's probably OK...
+                       $template->param(atomcommentsurl =>
+                               urlto($page, undef, 1).'comments.atom');
                }
        }
 
@@ -568,7 +762,7 @@ sub pagetemplate (@) {
                # the link. But, to update the number, blog pages
                # would have to update whenever comments of any inlines
                # page are added, which is not currently done.
-               if (commentsshown($page)) {
+               if ($shown) {
                        $template->param(commentslink =>
                                htmllink($page, $params{destpage}, $page,
                                        linktext => gettext("Comments"),
@@ -577,27 +771,89 @@ sub pagetemplate (@) {
                }
        }
 
+       # everything below this point is only relevant to the comments
+       # themselves
+       if (!exists $commentstate{$page}) {
+               return;
+       }
+       
+       if ($template->query(name => 'commentid')) {
+               $template->param(commentid => page_to_id($page));
+       }
+
        if ($template->query(name => 'commentuser')) {
                $template->param(commentuser =>
-                       $pagestate{$page}{comments}{commentuser});
+                       $commentstate{$page}{commentuser});
+       }
+
+       if ($template->query(name => 'commentopenid')) {
+               $template->param(commentopenid =>
+                       $commentstate{$page}{commentopenid});
        }
 
        if ($template->query(name => 'commentip')) {
                $template->param(commentip =>
-                       $pagestate{$page}{comments}{commentip});
+                       $commentstate{$page}{commentip});
        }
 
        if ($template->query(name => 'commentauthor')) {
                $template->param(commentauthor =>
-                       $pagestate{$page}{comments}{commentauthor});
+                       $commentstate{$page}{commentauthor});
        }
 
        if ($template->query(name => 'commentauthorurl')) {
                $template->param(commentauthorurl =>
-                       $pagestate{$page}{comments}{commentauthorurl});
+                       $commentstate{$page}{commentauthorurl});
+       }
+
+       if ($template->query(name => 'removeurl') &&
+           IkiWiki::Plugin::remove->can("check_canremove") &&
+           length $config{cgiurl}) {
+               $template->param(removeurl => IkiWiki::cgiurl(do => 'remove',
+                       page => $page));
+               $template->param(have_actions => 1);
        }
 }
 
+sub num_comments ($$) {
+       my $page=shift;
+       my $dir=shift;
+
+       my @comments=glob("$dir/$page/$config{comments_pagename}*._comment");
+       return @comments;
+}
+
+sub unique_comment_location ($$$) {
+       my $page=shift;
+
+       eval q{use Digest::MD5 'md5_hex'};
+       error($@) if $@;
+       my $content_md5=md5_hex(shift);
+
+       my $dir=shift;
+
+       my $location;
+       my $i = num_comments($page, $dir);
+       do {
+               $i++;
+               $location = "$page/$config{comments_pagename}${i}_${content_md5}";
+       } while (-e "$dir/$location._comment");
+
+       return $location;
+}
+
+sub page_to_id ($) {
+       # Converts a comment page name into a unique, legal html id
+       # addtibute value, that can be used as an anchor to link to the
+       # comment.
+       my $page=shift;
+
+       eval q{use Digest::MD5 'md5_hex'};
+       error($@) if $@;
+
+       return "comment-".md5_hex($page);
+}
+       
 package IkiWiki::PageSpec;
 
 sub match_postcomment ($$;@) {