Bug 428313: Properly expire the browser's CSS and JS cache when there

are new versions of those files. This also eliminates single-file skins
and should also allow Extensions to have skins.
r=glob, a=mkanat

2 files changed, 159 insertions, 20 deletions

diff --git a/Bugzilla/Install/Filesystem.pm b/Bugzilla/Install/Filesystem.pm
index db55576a4..20bd021ef 100644
--- a/Bugzilla/Install/Filesystem.pm
+++ b/Bugzilla/Install/Filesystem.pm
@@ -284,20 +284,6 @@ sub FILESYSTEM {
                                         contents => '' },
     );
 
-    # Each standard stylesheet has an associated custom stylesheet that
-    # we create. Also, we create placeholders for standard stylesheets
-    # for contrib skins which don't provide them themselves.
-    foreach my $skin_dir ("$skinsdir/custom", <$skinsdir/contrib/*>) {
-        next if basename($skin_dir) =~ /^cvs$/i;
-        foreach my $base_css (<$skinsdir/standard/*.css>) {
-            _add_custom_css($skin_dir, basename($base_css), \%create_files);
-        }
-        foreach my $dir_css (<$skinsdir/standard/*/*.css>) {
-            $dir_css =~ s{.+?([^/]+/[^/]+)$}{$1};
-            _add_custom_css($skin_dir, $dir_css, \%create_files);
-        }
-    }
-
     # Because checksetup controls the creation of index.html separately
     # from all other files, it gets its very own hash.
     my %index_html = (
@@ -455,20 +441,53 @@ EOT
         print "Removing duplicates directory...\n";
         rmtree("$datadir/duplicates");
     }
+
+    _remove_empty_css_files();
+    _convert_single_file_skins();
 }
 
-# A simple helper for creating "empty" CSS files.
-sub _add_custom_css {
-    my ($skin_dir, $path, $create_files) = @_;
-    $create_files->{"$skin_dir/$path"} = { perms => WS_SERVE, contents => <<EOT
+sub _remove_empty_css_files {
+    my $skinsdir = bz_locations()->{'skinsdir'};
+    foreach my $css_file (glob("$skinsdir/custom/*.css"),
+                          glob("$skinsdir/contrib/*/*.css"))
+    {
+        _remove_empty_css($css_file);
+    }
+}
+
+# A simple helper for the update code that removes "empty" CSS files.
+sub _remove_empty_css {
+    my ($file) = @_;
+    my $basename = basename($file);
+    my $empty_contents = <<EOT;
 /*
- * Custom rules for $path.
+ * Custom rules for $basename.
  * The rules you put here override rules in that stylesheet.
  */
 EOT
+    if (length($empty_contents) == -s $file) {
+        open(my $fh, '<', $file) or warn "$file: $!";
+        my $file_contents;
+        { local $/; $file_contents = <$fh>; }
+        if ($file_contents eq $empty_contents) {
+            print install_string('file_remove', { name => $file }), "\n";
+            unlink $file or warn "$file: $!";
+        }
     };
 }
 
+# We used to allow a single css file in the skins/contrib/ directory
+# to be a whole skin.
+sub _convert_single_file_skins {
+    my $skinsdir = bz_locations()->{'skinsdir'};
+    foreach my $skin_file (glob "$skinsdir/contrib/*.css") {
+        my $dir_name = $skin_file;
+        $dir_name =~ s/\.css$//;
+        mkdir $dir_name or warn "$dir_name: $!";
+        _rename_file($skin_file, "$dir_name/global.css");
+    }
+}
+
 sub create_htaccess {
     _create_files(%{FILESYSTEM()->{htaccess}});
 
@@ -492,7 +511,7 @@ sub create_htaccess {
 
 sub _rename_file {
     my ($from, $to) = @_;
-    print "Renaming $from to $to...\n";
+    print install_string('file_rename', { from => $from, to => $to }), "\n";
     if (-e $to) {
         warn "$to already exists, not moving\n";
     }
diff --git a/Bugzilla/Template.pm b/Bugzilla/Template.pm
index 2c2d402a3..ffd702e62 100644
--- a/Bugzilla/Template.pm
+++ b/Bugzilla/Template.pm
@@ -358,6 +358,121 @@ sub get_bug_link {
     return qq{$pre<a href="$linkval" title="$title">$link_text</a>$post};
 }
 
+#####################
+# Header Generation #
+#####################
+
+# Returns the last modification time of a file, as an integer number of
+# seconds since the epoch.
+sub _mtime { return (stat($_[0]))[9] }
+
+sub mtime_filter {
+    my ($file_url) = @_;
+    my $cgi_path = bz_locations()->{'cgi_path'};
+    my $file_path = "$cgi_path/$file_url";
+    return "$file_url?" . _mtime($file_path);
+}
+
+# Set up the skin CSS cascade:
+#
+#  1. YUI CSS
+#  2. Standard Bugzilla stylesheet set (persistent)
+#  3. Standard Bugzilla stylesheet set (selectable)
+#  4. All third-party "skin" stylesheet sets (selectable)
+#  5. Page-specific styles
+#  6. Custom Bugzilla stylesheet set (persistent)
+#
+# "Selectable" skin file sets may be either preferred or alternate.
+# Exactly one is preferred, determined by the "skin" user preference.
+sub css_files {
+    my ($style_urls, $yui, $yui_css) = @_;
+    
+    # global.css goes on every page, and so does IE-fixes.css.
+    my @requested_css = ('skins/standard/global.css', @$style_urls,
+                         'skins/standard/IE-fixes.css');
+
+    my @yui_required_css;
+    foreach my $yui_name (@$yui) {
+        next if !$yui_css->{$yui_name};
+        push(@yui_required_css, "js/yui/assets/skins/sam/$yui_name.css");
+    }
+    unshift(@requested_css, @yui_required_css);
+    
+    my @css_sets = map { _css_link_set($_) } @requested_css;
+    
+    my %by_type = (standard => [], alternate => {}, skin => [], custom => []);
+    foreach my $set (@css_sets) {
+        foreach my $key (keys %$set) {
+            if ($key eq 'alternate') {
+                foreach my $alternate_skin (keys %{ $set->{alternate} }) {
+                    my $files = $by_type{alternate}->{$alternate_skin} ||= [];
+                    push(@$files, $set->{alternate}->{$alternate_skin});
+                }
+            }
+            else {
+                push(@{ $by_type{$key} }, $set->{$key});
+            }
+        }
+    }
+    
+    return \%by_type;
+}
+
+sub _css_link_set {
+    my ($file_name) = @_;
+
+    my $standard_mtime = _mtime($file_name);
+    my %set = (standard => $file_name . "?$standard_mtime");
+    
+    # We use (^|/) to allow Extensions to use the skins system if they
+    # want.
+    if ($file_name !~ m{(^|/)skins/standard/}) {
+        return \%set;
+    }
+    
+    my $user = Bugzilla->user;
+    my $cgi_path = bz_locations()->{'cgi_path'};
+    my $all_skins = $user->settings->{'skin'}->legal_values;    
+    my %skin_urls;
+    foreach my $option (@$all_skins) {
+        next if $option eq 'standard';
+        my $skin_file_name = $file_name;
+        $skin_file_name =~ s{(^|/)skins/standard/}{skins/contrib/$option/};
+        if (my $mtime = _mtime("$cgi_path/$skin_file_name")) {
+            $skin_urls{$option} = $skin_file_name . "?$mtime";
+        }
+    }
+    $set{alternate} = \%skin_urls;
+    
+    my $skin = $user->settings->{'skin'}->{'value'};
+    if ($skin ne 'standard' and defined $set{alternate}->{$skin}) {
+        $set{skin} = delete $set{alternate}->{$skin};
+    }
+    
+    my $custom_file_name = $file_name;
+    $custom_file_name =~ s{(^|/)skins/standard/}{skins/custom/};
+    if (my $custom_mtime = _mtime("$cgi_path/$custom_file_name")) {
+        $set{custom} = $custom_file_name . "?$custom_mtime";
+    }
+    
+    return \%set;
+}
+
+# YUI dependency resolution
+sub yui_resolve_deps {
+    my ($yui, $yui_deps) = @_;
+    
+    my @yui_resolved;
+    foreach my $yui_name (@$yui) {
+        my $deps = $yui_deps->{$yui_name} || [];
+        foreach my $dep (reverse @$deps) {
+            push(@yui_resolved, $dep) if !grep { $_ eq $dep } @yui_resolved;
+        }
+        push(@yui_resolved, $yui_name) if !grep { $_ eq $yui_name } @yui_resolved;
+    }
+    return \@yui_resolved;
+}
+
 ###############################################################################
 # Templatization Code
 
@@ -647,6 +762,8 @@ sub create {
             html_light => \&Bugzilla::Util::html_light_quote,
 
             email => \&Bugzilla::Util::email_filter,
+            
+            mtime_url => \&mtime_filter,
 
             # iCalendar contentline filter
             ics => [ sub {
@@ -769,6 +886,9 @@ sub create {
                     Bugzilla->fields({ by_name => 1 });
                 return $cache->{template_bug_fields};
             },
+            
+            'css_files' => \&css_files,
+            yui_resolve_deps => \&yui_resolve_deps,
 
             # Whether or not keywords are enabled, in this Bugzilla.
             'use_keywords' => sub { return Bugzilla::Keyword->any_exist; },