Extension support

bin/plerdwatcher

@@ -75,10 +75,17 @@ my $plerd;
 my $watcher;
 try {
     $plerd = Plerd->new( $config_ref );
+    my $filter;
+
+    my $trigger = defined (keys %{$plerd->post_triggers})
+        ? sprintf '\.(md|markdown|%s)$', join('|', keys %{$plerd->post_triggers})
+        : '\.(md|markdown)$';
+
+    $filter = qr/$trigger/;
 
     $watcher = File::ChangeNotify->instantiate_watcher (
         directories => [ $plerd->source_directory . '' ],
-        filter      => qr/\.(md|markdown)$/,
+        filter      => $filter,
     );
 }
 catch {

cpanfile

@@ -15,6 +15,7 @@ requires 'Try::Tiny';
 requires 'HTML::Strip';
 requires 'HTML::SocialMeta' => '0.72';
 requires 'List::Util' => '1.45';
+requires 'Module::Load';
 requires 'Readonly';
-requires 'Web::Mention' => '0.6'; 
+requires 'Web::Mention' => '0.6';
 requires 'Mojolicious::Lite';

lib/Plerd.pm

@@ -12,6 +12,8 @@ use URI;
 use Carp;
 use Try::Tiny;
 
+use Module::Load;
+
 use Plerd::Post;
 use Plerd::WebmentionQueue;
 
@@ -257,6 +259,23 @@ has 'tags_map' => (
     clearer => 'clear_tags_map',
 );
 
+has 'extensions' => (
+    is => 'ro',
+    isa => 'Maybe[ArrayRef[Str]]'
+);
+
+has 'extension_preferences' => (
+    is => 'ro',
+    isa => 'Maybe[HashRef]',
+);
+
+has 'post_triggers' => (
+    is => 'ro',
+    isa => 'Maybe[HashRef[Str]]',
+    lazy_build => 1,
+);
+
+
 sub BUILD {
     my $self = shift;
 
@@ -273,6 +292,16 @@ sub BUILD {
         }
     }
 
+    foreach my $extension (@{$self->extensions // []}) {
+        try {
+            load $extension;
+        }
+        catch {
+            my $error = shift || "Unknown error";
+            die "Can't load extension: '$extension': $error\n";
+        };
+    }
+
     return $self;
 }
 
@@ -609,15 +638,24 @@ sub _build_recent_posts {
 
 sub _build_posts {
     my $self = shift;
+    my @posts;
+    my $triggers = $self->post_triggers;
+
+    foreach my $file (sort { $a->basename cmp $b->basename } $self->source_directory->children) {
+        if ($file =~ m/\.(?:markdown|md)$/) {
+            push @posts, Plerd::Post->new( plerd => $self, source_file => $file )
+        } else {
+            foreach my $trigger (keys %{$triggers}) {
+                if ($file =~ m/\.$trigger$/i) {
+                    push @posts, $$triggers{$trigger}->new(plerd => $self, source_file => $file);
+                    last;
+                }
+            }
+        }
+    }
 
-    my @posts = sort { $b->date <=> $a->date }
-                map { Plerd::Post->new( plerd => $self, source_file => $_ ) }
-                sort { $a->basename cmp $b->basename }
-                grep { /\.markdown$|\.md$/ }
-                $self->source_directory->children
-    ;
+    return [sort { $b->date <=> $a->date } @posts];
 
-    return \@posts;
 }
 
 sub _build_index_of_post_with_guid {
@@ -664,6 +702,19 @@ sub _throw_template_exception {
         . "template file $template_file: $error\n";
 }
 
+sub _build_post_triggers {
+    my $self = shift;
+    my %triggers;
+
+    foreach my $classref (@{$self->extensions // []}){
+        if ($classref->can('file_type')) {
+            $triggers{ $classref->file_type } = $classref;
+        }
+    }
+
+    return \%triggers;
+}
+
 sub generates_post_guids {
     carp "generates_post_guids() is deprecated. (Also, it doesn't do anything "
          . "anyway.)";
@@ -954,6 +1005,22 @@ tag index HTML files.
 This is a L<URI> object that points to the tag index.  It is
 particularly helpful when creating navigation.
 
+=item extensions
+
+An arrayref of strings, representing the plugins to load when a new Plerd
+instance is created.
+
+=item extension_preferences
+
+A hashref of config options for extensions. It is up to each individual extension
+to decide how to act upon the contents therein.
+
+=item post_triggers
+
+A hashref that maps extensions to file types. The key is used as a regex to deduce what
+source file types the particular Post extension using to render pages.
+The value is a reference to that particular extension.
+
 =back
 
 =head1 OBJECT METHODS

t/basic.t

@@ -8,6 +8,7 @@ use DateTime;
 
 use FindBin;
 use lib "$FindBin::Bin/../lib";
+use lib "$FindBin::Bin/lib";
 
 use_ok( 'Plerd' );
 
@@ -54,9 +55,10 @@ unlink "$FindBin::Bin/source/no-title.md";
 
 $plerd->publish_all;
 
-# The "+5" below accounts for the generated recent, archive, and RSS files,
+# The "+4" below accounts for the generated recent, archive, and RSS files,
 # a index.html symlink, and a tags directory.
-my $expected_docroot_count = scalar( $source_dir->children( no_hidden => 1 ) ) + 5;
+my $expected_docroot_count = scalar( $source_dir->children( no_hidden => 1 ) ) + 4;
+
 is( scalar( $docroot_dir->children ),
             $expected_docroot_count,
             "Correct number of files generated in docroot."
@@ -331,6 +333,28 @@ like( $post,
     'Metatags: Defined default alt-text',
 );
 
+}
+{
+### Test extension-support
+my $extension_plerd = Plerd->new(
+    path         => $FindBin::Bin,
+    title        => 'Test Blog',
+    author_name  => 'Nobody',
+    author_email => 'nobody@example.com',
+    extensions   => ['TestExtension'],
+    base_uri     => URI->new ( 'http://blog.example.com/' ),
+    image        => URI->new ( 'http://blog.example.com/logo.png' ),
+
+);
+
+$extension_plerd->publish_all;
+
+my $post = Path::Class::File->new( $docroot_dir, "$ymd-a-very-special-source-file.html" )->slurp;
+like( $post,
+    qr{.sdrawkcab dm. si hcihw md.},
+    'Extensions: Plerd can publish with extensions',
+);
+
 }
 
 done_testing();

t/lib/TestExtension.pm

@@ -0,0 +1,68 @@
+package TestExtension;
+use Plerd::Post;
+use Moose;
+use strict;
+
+use 5.010;
+
+use warnings FATAL => 'all';
+
+extends "Plerd::Post";
+
+sub file_type {
+    'dm';
+}
+
+around 'body' => sub {
+    my $orig = shift;
+    my $self = shift;
+    if (@_){
+        # "Setter"
+        my $body = shift;
+
+        # first time body is called, reverse it!
+        $body = reverse $body unless $self->$orig;
+
+        $self->$orig($body);
+    } else {
+        # "Getter"
+        $self->$orig();
+    }
+};
+
+1;
+
+
+=head1 NAME
+
+TestExtension - A L<Plerd::Post> extension to showcase the extension capabilities of L<Plerd>.
+
+=head1 DESCRIPTION
+
+This extension doesn't do anything truly useful. It's sole purpose is showcasing the extension capabilities.
+
+What it does in fact do, though, is reversing the body of the document (the first time it's set).
+
+It's rather useless.
+
+=head1 OBJECT ATTRIBUTES
+
+=head2 Read-only attributes, set during construction
+
+=over
+
+=item file_type
+
+A regex-compatible string which indicate what file types to associate with the Extension.
+This is set to "dm" (which happens to be "md" spelled backwards)
+
+=item body
+
+The original L<Plerd::Post> body, except that the first time this attribute is set, it gets reversed.
+
+=back
+
+=head2 Other attributes
+
+All other attributes are inherited from L<Plerd::Post> Please consult that documentation for their docs.
+

t/source_model/extension.dm

@@ -0,0 +1,4 @@
+title: A very special source file
+
+
+It's only special because it's file type is .dm which is .md backwards. This is to see if it gets processed by an extension.