gitweb: Change the way "content tags" ('ctags') are handled

The major change is removing the ability to edit content tags (ctags)
in a web browser.

The interface was created by gitweb, while actual editing of tags was
to be done by external script; the API was not defined, and neither
was provided example implementation.  Such split is also a bit fragile
- interface and implementation have to be kept in sync.  Gitweb
provided only ability to add tags; you could not edit tags nor delete
them.

Format of ctags is now described in the comment above git_get_project_ctags
subroutine.  Gitweb now is more robust with respect to original ctags
format; it also accepts two new formats: $GIT_DIR/ctags file, with one
content tag per line, and multi-value `gitweb.ctag' config variable.

Gathering all ctags of all project is now put in git_gather_all_ctags
subroutine, making git_project_list_body more clear.

git_populate_project_tagcloud subroutine now generates data used for
tag cloud, including generation of ctag link, also in the case
HTML::TagCloud module is unavailable.  Links are now generated using
href() subroutine - this is more robust, as ctags might contain '?',
';' and '=' special characters that need to be escaped in query param.
Shown tags are HTML-escaped.

The generation of tag cloud in git_show_project_tagcloud in the case
when HTML::TagCloud is not available is now changed slightly.

The 'content tags' field on project summary page is made more in line
with other fields in "projects_list" table.  Because one cannot now
add new tags from web interface, this field is no longer displayed
when there are no content tags for given project.

Ctags-issue-Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Ctags-issue-Reported-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Jakub Narebski <jnareb@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/gitweb/gitweb.perl b/gitweb/gitweb.perl
index 014b33b50a88c520e81181d4c487340afa17763c..60cb772c5834255acabe5eb61d83787fc91f96a0 100755 (executable)
--- a/gitweb/gitweb.perl
+++ b/gitweb/gitweb.perl
@@ -412,20 +412,23 @@ our %feature = (
                'override' => 0,
                'default' => []},
 
-       # Allow gitweb scan project content tags described in ctags/
-       # of project repository, and display the popular Web 2.0-ish
-       # "tag cloud" near the project list. Note that this is something
-       # COMPLETELY different from the normal Git tags.
+       # Allow gitweb scan project content tags of project repository,
+       # and display the popular Web 2.0-ish "tag cloud" near the projects
+       # list.  Note that this is something COMPLETELY different from the
+       # normal Git tags.
 
        # gitweb by itself can show existing tags, but it does not handle
-       # tagging itself; you need an external application for that.
-       # For an example script, check Girocco's cgi/tagproj.cgi.
+       # tagging itself; you need to do it externally, outside gitweb.
+       # The format is described in git_get_project_ctags() subroutine.
        # You may want to install the HTML::TagCloud Perl module to get
        # a pretty tag cloud instead of just a list of tags.
 
        # To enable system wide have in $GITWEB_CONFIG
-       # $feature{'ctags'}{'default'} = ['path_to_tag_script'];
+       # $feature{'ctags'}{'default'} = [1];
        # Project specific override is not supported.
+
+       # In the future whether ctags editing is enabled might depend
+       # on the value, but using 1 should always mean no editing of ctags.
        'ctags' => {
                'override' => 0,
                'default' => [0]},
@@ -703,6 +706,7 @@ our @cgi_param_mapping = (
        snapshot_format => "sf",
        extra_options => "opt",
        search_use_regexp => "sr",
+       ctag => "by_tag",
        # this must be last entry (for manipulation from JavaScript)
        javascript => "js"
 );
@@ -2572,23 +2576,66 @@ sub git_get_project_description {
        return $descr;
 }
 
+# supported formats:
+# * $GIT_DIR/ctags/<tagname> file (in 'ctags' subdirectory)
+#   - if its contents is a number, use it as tag weight,
+#   - otherwise add a tag with weight 1
+# * $GIT_DIR/ctags file, each line is a tag (with weight 1)
+#   the same value multiple times increases tag weight
+# * `gitweb.ctag' multi-valued repo config variable
 sub git_get_project_ctags {
-       my $path = shift;
+       my $project = shift;
        my $ctags = {};
 
-       $git_dir = "$projectroot/$path";
-       opendir my $dh, "$git_dir/ctags"
-               or return $ctags;
-       foreach (grep { -f $_ } map { "$git_dir/ctags/$_" } readdir($dh)) {
-               open my $ct, '<', $_ or next;
-               my $val = <$ct>;
-               chomp $val;
-               close $ct;
-               my $ctag = $_; $ctag =~ s#.*/##;
-               $ctags->{$ctag} = $val;
+       $git_dir = "$projectroot/$project";
+       if (opendir my $dh, "$git_dir/ctags") {
+               my @files = grep { -f $_ } map { "$git_dir/ctags/$_" } readdir($dh);
+               foreach my $tagfile (@files) {
+                       open my $ct, '<', $tagfile
+                               or next;
+                       my $val = <$ct>;
+                       chomp $val if $val;
+                       close $ct;
+
+                       (my $ctag = $tagfile) =~ s#.*/##;
+                       if ($val =~ /\d+/) {
+                               $ctags->{$ctag} = $val;
+                       } else {
+                               $ctags->{$ctag} = 1;
+                       }
+               }
+               closedir $dh;
+
+       } elsif (open my $fh, '<', "$git_dir/ctags") {
+               while (my $line = <$fh>) {
+                       chomp $line;
+                       $ctags->{$line}++ if $line;
+               }
+               close $fh;
+
+       } else {
+               my $taglist = config_to_multi(git_get_project_config('ctag'));
+               foreach my $tag (@$taglist) {
+                       $ctags->{$tag}++;
+               }
        }
-       closedir $dh;
-       $ctags;
+
+       return $ctags;
+}
+
+# return hash, where keys are content tags ('ctags'),
+# and values are sum of weights of given tag in every project
+sub git_gather_all_ctags {
+       my $projects = shift;
+       my $ctags = {};
+
+       foreach my $p (@$projects) {
+               foreach my $ct (keys %{$p->{'ctags'}}) {
+                       $ctags->{$ct} += $p->{'ctags'}->{$ct};
+               }
+       }
+
+       return $ctags;
 }
 
 sub git_populate_project_tagcloud {
@@ -2608,31 +2655,41 @@ sub git_populate_project_tagcloud {
        my $cloud;
        if (eval { require HTML::TagCloud; 1; }) {
                $cloud = HTML::TagCloud->new;
-               foreach (sort keys %ctags_lc) {
+               foreach my $ctag (sort keys %ctags_lc) {
                        # Pad the title with spaces so that the cloud looks
                        # less crammed.
-                       my $title = $ctags_lc{$_}->{topname};
+                       my $title = esc_html($ctags_lc{$ctag}->{topname});
                        $title =~ s/ /&nbsp;/g;
                        $title =~ s/^/&nbsp;/g;
                        $title =~ s/$/&nbsp;/g;
-                       $cloud->add($title, $home_link."?by_tag=".$_, $ctags_lc{$_}->{count});
+                       $cloud->add($title, href(project=>undef, ctag=>$ctag),
+                                   $ctags_lc{$ctag}->{count});
                }
        } else {
-               $cloud = \%ctags_lc;
+               $cloud = {};
+               foreach my $ctag (keys %ctags_lc) {
+                       my $title = $ctags_lc{$ctag}->{topname};
+                       $cloud->{$ctag}{count} = $ctags_lc{$ctag}->{count};
+                       $cloud->{$ctag}{ctag} =
+                               $cgi->a({-href=>href(project=>undef, ctag=>$ctag)},
+                                 esc_html($title, -nbsp=>1));
+               }
        }
-       $cloud;
+       return $cloud;
 }
 
 sub git_show_project_tagcloud {
        my ($cloud, $count) = @_;
-       print STDERR ref($cloud)."..\n";
        if (ref $cloud eq 'HTML::TagCloud') {
                return $cloud->html_and_css($count);
        } else {
-               my @tags = sort { $cloud->{$a}->{count} <=> $cloud->{$b}->{count} } keys %$cloud;
-               return '<p align="center">' . join (', ', map {
-                       $cgi->a({-href=>"$home_link?by_tag=$_"}, $cloud->{$_}->{topname})
-               } splice(@tags, 0, $count)) . '</p>';
+               my @tags = sort { $cloud->{$a}->{'count'} <=> $cloud->{$b}->{'count'} } keys %$cloud;
+               return
+                       '<div id="htmltagcloud"'.($project ? '' : ' align="center"').'>' .
+                       join (', ', map {
+                               $cloud->{$_}->{'ctag'}
+                       } splice(@tags, 0, $count)) .
+                       '</div>';
        }
 }
 
@@ -4920,13 +4977,8 @@ sub git_project_list_body {
        @projects = sort_projects_list(\@projects, $order);
 
        if ($show_ctags) {
-               my %ctags;
-               foreach my $p (@projects) {
-                       foreach my $ct (keys %{$p->{'ctags'}}) {
-                               $ctags{$ct} += $p->{'ctags'}->{$ct};
-                       }
-               }
-               my $cloud = git_populate_project_tagcloud(\%ctags);
+               my $ctags = git_gather_all_ctags(\@projects);
+               my $cloud = git_populate_project_tagcloud($ctags);
                print git_show_project_tagcloud($cloud, 64);
        }
 
@@ -5521,13 +5573,14 @@ sub git_summary {
        my $show_ctags = gitweb_check_feature('ctags');
        if ($show_ctags) {
                my $ctags = git_get_project_ctags($project);
-               my $cloud = git_populate_project_tagcloud($ctags);
-               print "<tr id=\"metadata_ctags\"><td>Content tags:<br />";
-               print "</td>\n<td>" unless %$ctags;
-               print "<form action=\"$show_ctags\" method=\"post\"><input type=\"hidden\" name=\"p\" value=\"$project\" />Add: <input type=\"text\" name=\"t\" size=\"8\" /></form>";
-               print "</td>\n<td>" if %$ctags;
-               print git_show_project_tagcloud($cloud, 48);
-               print "</td></tr>";
+               if (%$ctags) {
+                       # without ability to add tags, don't show if there are none
+                       my $cloud = git_populate_project_tagcloud($ctags);
+                       print "<tr id=\"metadata_ctags\">" .
+                             "<td>content tags</td>" .
+                             "<td>".git_show_project_tagcloud($cloud, 48)."</td>" .
+                             "</tr>\n";
+               }
        }
 
        print "</table>\n";