--- a/src/pyams_skin/interfaces/resources.py	Mon Dec 10 15:49:32 2018 +0100
+++ b/src/pyams_skin/interfaces/resources.py	Wed Dec 12 10:08:24 2018 +0100
@@ -12,20 +12,15 @@
 
 __docformat__ = 'restructuredtext'
 
-# import standard library
-
-# import interfaces
-
-# import packages
-from zope.interface import Interface
+from zope.interface import Interface, Attribute
 
 
 class IResources(Interface):
     """Get list of CSS and Javascript resources associated with given context"""
 
-    def get_resources(self):
-        """Include page resources
+    resources = Attribute("Resources to include")
+    """Iterable of resources to include into page
 
-        The best way to handle resources is to use Fanstatic to automatically
-        include CSS and Javascript tags
-        """
+    The best way to handle resources is to use Fanstatic to automatically
+    include CSS and Javascript tags
+    """

--- a/src/pyams_skin/resources.py	Mon Dec 10 15:49:32 2018 +0100
+++ b/src/pyams_skin/resources.py	Wed Dec 12 10:08:24 2018 +0100
@@ -12,26 +12,68 @@
 
 __docformat__ = 'restructuredtext'
 
-
-# import standard library
+from fanstatic import get_library_registry
+from pyramid.interfaces import IRequest
+from zope.dublincore.interfaces import IZopeDublinCore
+from zope.interface import Interface
 
-# import interfaces
+from pyams_skin import myams
+from pyams_skin.interfaces import ISkinnable
 from pyams_skin.interfaces.resources import IResources
+from pyams_skin.layer import IPyAMSUserLayer
+from pyams_utils.adapter import ContextRequestViewAdapter, adapter_config
+from pyams_utils.fanstatic import ExternalResource
 from pyams_utils.interfaces.tales import ITALESExtension
-from pyramid.interfaces import IRequest
+from pyams_utils.traversing import get_parent
+from pyams_utils.url import absolute_url
 
-# import packages
-from pyams_skin import myams
-from pyams_utils.adapter import adapter_config, ContextRequestViewAdapter
-from zope.interface import Interface
+for library in get_library_registry().values():
+    break
+else:
+    try:
+        from pyams_skin import library
+    except ImportError:
+        from pyams_default_theme import library
 
 
 @adapter_config(context=(Interface, IRequest, Interface), provides=IResources)
 class ResourcesAdapter(ContextRequestViewAdapter):
     """Get context resources"""
 
-    def get_resources(self):
-        myams.need()
+    resources = (myams,)
+
+
+@adapter_config(name='custom-skin', context=(Interface, IPyAMSUserLayer, Interface), provides=IResources)
+class CustomSkinResourcesAdapter(ContextRequestViewAdapter):
+    """Custom skin resources adapter"""
+
+    weight = 999
+
+    @property
+    def resources(self):
+        main_resources = self.request.registry.queryMultiAdapter((self.context, self.request, self.view), IResources)
+        if main_resources is not None:
+            parent_resources = (main_resources.resources[-1],)
+            skinnable = get_parent(self.request.context, ISkinnable)
+            skin_parent = skinnable.skin_parent
+            custom_css = skin_parent.custom_stylesheet
+            if custom_css:
+                modified = IZopeDublinCore(custom_css).modified
+                custom_css_url = absolute_url(custom_css, self.request, query={'_': modified.timestamp()})
+                resource = library.known_resources.get(custom_css_url)
+                if resource is None:
+                    resource = ExternalResource(library, custom_css_url, resource_type='css',
+                                                depends=parent_resources)
+                yield resource
+            custom_js = skin_parent.custom_script
+            if custom_js:
+                modified = IZopeDublinCore(custom_js).modified
+                custom_js_url = absolute_url(custom_js, self.request, query={'_': modified.timestamp()})
+                resource = library.known_resources.get(custom_js_url)
+                if resource is None:
+                    resource = ExternalResource(library, custom_js_url, resource_type='js',
+                                                depends=parent_resources, bottom=True)
+                yield resource
 
 
 @adapter_config(name='resources', context=(Interface, IRequest, Interface), provides=ITALESExtension)
@@ -41,6 +83,8 @@
     def render(self, context=None):
         if context is None:
             context = self.context
-        for name, adapter in self.request.registry.getAdapters((context, self.request, self.view), IResources):
-            adapter.get_resources()
+        for name, adapter in sorted(self.request.registry.getAdapters((context, self.request, self.view), IResources),
+                                    key=lambda x: getattr(x[1], 'weight', 0)):
+            for resource in adapter.resources:
+                resource.need()
         return ''