2 files changed, 26 insertions, 1 deletions
diff --git a/lib/Tree/Transform/XSLTish/Transformer.pm b/lib/Tree/Transform/XSLTish/Transformer.pm
index c6102a7..fd61ea6 100644
--- a/lib/Tree/Transform/XSLTish/Transformer.pm
+++ b/lib/Tree/Transform/XSLTish/Transformer.pm
@@ -36,9 +36,22 @@ has 'context_stack' => (
 has 'engine' => (
     is => 'ro',
     isa => 'Tree::Transform::XSLTish::Engine',
-    default => sub { Tree::XPathEngine->new() },
+    lazy => 1,
+    builder => '_build_engine',
 );
 
+sub _build_engine {
+    my ($self)=@_;
+
+    if ($self->rules_package) {
+        my $factory=Tree::Transform::XSLTish::Utils::_engine_factory($self->rules_package);
+        if ($$factory) {
+            return $$factory->();
+        }
+    }
+    return Tree::XPathEngine->new();
+}
+
 sub it { $_[0]->context->current_node }
 
 sub transform {
diff --git a/lib/Tree/Transform/XSLTish/Utils.pm b/lib/Tree/Transform/XSLTish/Utils.pm
index 11a25cb..bed1167 100644
--- a/lib/Tree/Transform/XSLTish/Utils.pm
+++ b/lib/Tree/Transform/XSLTish/Utils.pm
@@ -14,6 +14,18 @@ sub _rules_store {
     return $pack->get_package_symbol($RULES_NAME);
 }
 
+my $ENGINE_FACTORY_NAME='$_tree_transform_engine_factory';
+
+sub _engine_factory {
+    my $pack=Class::MOP::Class->initialize($_[0]);
+
+    if (! $pack->has_package_symbol($ENGINE_FACTORY_NAME) ) { 
+        $pack->add_package_symbol($ENGINE_FACTORY_NAME,undef);
+    }
+    return $pack->get_package_symbol($ENGINE_FACTORY_NAME);
+}
+
+
 sub _get_inheritance {
     return Class::MOP::Class->initialize($_[0])->class_precedence_list;
 }