Add stages to Asset so the checksum is less volatile

Author: Jan Henning Thorsen

lib/Mojolicious/Plugin/AssetPack.pm

@@ -132,12 +132,14 @@ sub _process {
     $asset->checksum;
   }
 
-  for my $method (qw(before_process process after_process)) {
+  for my $stage (qw(before_process process after_process)) {
+    $assets->map(stage => $stage);
+
     for my $pipe (@{$self->{pipes}}) {
-      next unless $pipe->can($method);
+      next unless $pipe->can($stage);
       local $pipe->{topic} = $topic;
-      diag '%s->%s("%s")', ref $pipe, $method, $topic if DEBUG;
-      $pipe->$method($assets);
+      diag '%s->%s("%s")', ref $pipe, $stage, $topic if DEBUG;
+      $pipe->$stage($assets);
     }
   }
 

lib/Mojolicious/Plugin/AssetPack/Asset.pm

@@ -13,7 +13,8 @@ $TAG_TEMPLATE{js}  = [qw(script src)];
 $TAG_TEMPLATE{$_} = [qw(img src)]    for qw(gif jpg jpeg png svg);
 $TAG_TEMPLATE{$_} = [qw(source src)] for qw(mp3 mp4 ogg ogv webm);
 
-has checksum => sub { Mojolicious::Plugin::AssetPack::Util::checksum(shift->content) };
+has stage => 'init';
+
 has format => sub {
   my $self = shift;
   my $name = $self->url =~ /^https?:/ ? Mojo::URL->new($self->url)->path->[-1] : (split m!(\\|/)!, $self->url)[-1];
@@ -69,6 +70,15 @@ sub asset {
   return $clone;
 }
 
+sub checksum {
+  my $self = shift;
+  return $self->{checksum} ||= Mojolicious::Plugin::AssetPack::Util::checksum($self->content) unless @_;
+  Carp::confess(qq(Cannot change checksum when stage is "@{[$self->stage]}")) unless $self->stage eq 'before_process';
+  $self->{checksum} = shift;
+  diag qq(checksum(@{[$self->url]}) = $self->{checksum}) if DEBUG;
+  return $self;
+}
+
 sub content {
   my $self = shift;
   return $self->_asset->slurp unless @_;
@@ -98,7 +108,7 @@ sub _default_tag_for {
 
 sub FROM_JSON {
   my ($self, $attrs) = @_;
-  $self->$_($attrs->{$_}) for grep { defined $attrs->{$_} } qw(checksum format minified);
+  $self->$_($attrs->{$_}) for grep { defined $attrs->{$_} } qw(format minified);
   $self;
 }
 
@@ -125,13 +135,6 @@ L<Mojolicious::Plugin::AssetPack::Asset> represents an asset.
 
 =head1 ATTRIBUTES
 
-=head2 checksum
-
-  $str = $self->checksum;
-  $self = $self->checksum($str);
-
-The L<checksum|Mojolicious::Plugin::AssetPack::Util/checksum> of L</content>.
-
 =head2 format
 
   $str = $self->format;
@@ -161,6 +164,13 @@ Returns the basename of L</url>, without extension.
 Can be used to register a custom render method for this asset. This is called
 by L<Mojolicious::Plugin::AssetPack::Store/serve_asset>.
 
+=head2 stage
+
+  $str = $self->stage;
+  $self = $self->stage("process");
+
+Contains the pipe stage name "before_process", "process" or "after_process".
+
 =head2 tag_for
 
   $code = $self->tag_for;
@@ -207,6 +217,14 @@ content or path from this object.
 
 This method is EXPERIMENTAL.
 
+=head2 checksum
+
+  $str = $self->checksum;
+  $self = $self->checksum($str);
+
+The L<checksum|Mojolicious::Plugin::AssetPack::Util/checksum> of L</content>.
+The value can only be changed if L</stage> is "before_process".
+
 =head2 content
 
   $bytes = $self->content;

lib/Mojolicious/Plugin/AssetPack/Pipe/Combine.pm

@@ -31,9 +31,15 @@ sub process {
     my $checksum = checksum $combine->map('checksum')->join(':');
     my $content = $combine->map('content')->map(sub { /\n$/ ? $_ : "$_\n" })->join;
     diag 'Combining assets into "%s" with checksum %s.', $self->topic, $checksum if DEBUG;
-    push @$assets,
-      Mojolicious::Plugin::AssetPack::Asset->new(url => $self->topic)->checksum($checksum)->minified(1)
-      ->content($content);
+    push(
+      @$assets,
+      Mojolicious::Plugin::AssetPack::Asset->new(
+        checksum => $checksum,
+        content  => $content,
+        minified => 1,
+        url      => $self->topic,
+      )
+    );
   }
 }
 

lib/Mojolicious/Plugin/AssetPack/Pipe/Sass.pm

@@ -15,6 +15,19 @@ $SOURCE_MAP_PLACEHOLDER =~ s!::!_!g;
 has functions => sub { +{} };
 has generate_source_map => sub { shift->app->mode eq 'development' ? 1 : 0 };
 
+sub before_process {
+  my ($self, $assets) = @_;
+
+  return $assets->each(sub {
+    my ($asset, $index) = @_;
+    return if $asset->format !~ $FORMAT_RE;
+    my @paths = (_include_path_for_asset($asset), @{$self->store->paths});
+    my $content = $asset->content;
+    $asset->checksum($self->_checksum(\$content, $asset, [grep {$_} @paths]));
+    $asset->content($content) unless $asset->path;
+  });
+}
+
 sub process {
   my ($self, $assets) = @_;
   my $store = $self->assetpack->store;
@@ -33,29 +46,24 @@ sub process {
 
   return $assets->each(sub {
     my ($asset, $index) = @_;
-
     return if $asset->format !~ $FORMAT_RE;
+
     my ($attrs, $content) = ($asset->TO_JSON, $asset->content);
-    local $self->{checksum_for_file} = {};
-    local $opts{include_paths}[0] = _include_path($asset);
     $attrs->{minified} = $self->assetpack->minify;
     $attrs->{key}      = sprintf 'sass%s', $attrs->{minified} ? '-min' : '';
     $attrs->{format}   = 'css';
-    $attrs->{checksum} = $self->_checksum(\$content, $asset, $opts{include_paths});
 
     return $asset->content($file)->FROM_JSON($attrs) if $file = $store->load($attrs);
     return if $asset->isa('Mojolicious::Plugin::AssetPack::Asset::Null');
-    $opts{include_paths}[0] = $asset->path ? $asset->path->dirname : undef;
-    $opts{include_paths} = [grep {$_} @{$opts{include_paths}}];
-    diag 'Process "%s" with checksum %s.', $asset->url, $attrs->{checksum} if DEBUG;
+    local $opts{include_paths}[0] = $asset->path ? $asset->path->dirname : undef;
+    local $opts{include_paths} = [grep {$_} @{$opts{include_paths}}];
+    diag 'Process "%s" with checksum %s.', $asset->url, $asset->checksum if DEBUG;
 
     if ($self->{has_module} //= eval { load_module 'CSS::Sass'; 1 }) {
       $opts{output_style} = _output_style($attrs->{minified});
       $content = CSS::Sass::sass2scss($content) if $asset->format eq 'sass';
       my ($css, $err, $stats) = CSS::Sass::sass_compile($content, %opts);
-      if ($err) {
-        die sprintf '[Pipe::Sass] Could not compile "%s" with opts=%s: %s', $asset->url, dumper(\%opts), $err;
-      }
+      $err and Carp::confess(qq/[Pipe::Sass] Could not compile "@{[$asset->url]}" with opts=@{[dumper(\%opts)]}: $err/);
       $css = Mojo::Util::encode('UTF-8', $css);
       $self->_add_source_map_asset($asset, \$css, $stats) if $stats->{source_map_string};
       $asset->content($store->save(\$css, $attrs))->FROM_JSON($attrs);
@@ -94,7 +102,6 @@ sub _checksum {
   my $store = $self->assetpack->store;
   my @c     = (checksum $$ref);
 
-SEARCH:
   while ($$ref =~ /$IMPORT_RE/gs) {
     my $pre      = $1;
     my $rel_path = $4;
@@ -113,12 +120,12 @@ SEARCH:
     next if $rel_path =~ m!^https?://! and !$dynamic;
 
     unshift @basename, "_$name.$ext", "$name.$ext" unless $name =~ /\.$ext$/;
-    my $imported = $store->asset([map { join '/', @rel, $_ } @basename], $paths)
-      or die qq([Pipe::Sass] Could not find "$rel_path" file in @$paths);
+    my $imported = $self->store->asset([map { join '/', @rel, $_ } @basename], $paths)
+      or Carp::confess(qq([Pipe::Sass] Could not find "$rel_path" file in [@{[join ', ', @$paths]}].));
 
     if ($imported->path) {
       diag '@import "%s" (%s)', $rel_path, $imported->path if DEBUG >= 2;
-      local $paths->[0] = _include_path($imported);
+      local $paths->[0] = _include_path_for_asset($imported);
       push @c, $self->_checksum(\$imported->content, $imported, $paths);
     }
     else {
@@ -132,7 +139,7 @@ SEARCH:
   return checksum join ':', @c;
 }
 
-sub _include_path {
+sub _include_path_for_asset {
   my $asset = shift;
   return $asset->url if $asset->url =~ m!^https?://!;
   return $asset->path->dirname if $asset->path;
@@ -224,6 +231,10 @@ dev tools.
 
 =head1 METHODS
 
+=head2 before_process
+
+See L<Mojolicious::Plugin::AssetPack::Pipe/before_process>.
+
 =head2 process
 
 See L<Mojolicious::Plugin::AssetPack::Pipe/process>.