Add common logic for xref buttons, links when viewing object

about dang time for this..probaby needs improvement but a good start

tailbone/views/master.py

@@ -2502,8 +2502,23 @@ class MasterView(View):
         """
         Method stub, so subclass can always invoke super() for it.
         """
+        obj = kwargs['instance']
+        kwargs['xref_buttons'] = self.get_xref_buttons(obj)
+        kwargs['xref_links'] = self.get_xref_links(obj)
         return kwargs
 
+    def get_xref_buttons(self, obj):
+        buttons = []
+        for supp in self.iter_view_supplements():
+            buttons.extend(supp.get_xref_buttons(obj))
+        return buttons
+
+    def get_xref_links(self, obj):
+        links = []
+        for supp in self.iter_view_supplements():
+            links.extend(supp.get_xref_links(obj))
+        return links
+
     def template_kwargs_edit(self, **kwargs):
         """
         Method stub, so subclass can always invoke super() for it.
@@ -5062,10 +5077,8 @@ class ViewSupplement(object):
 
     def __init__(self, master):
         self.master = master
-
-    @property
-    def model(self):
-        return self.master.model
+        self.request = master.request
+        self.model = master.model
 
     def get_grid_query(self, query):
         """
@@ -5111,6 +5124,12 @@ class ViewSupplement(object):
         renderers, default values etc. for them.
         """
 
+    def get_xref_buttons(self, obj):
+        return []
+
+    def get_xref_links(self, obj):
+        return []
+
     def get_version_child_classes(self):
         """
         Return a list of additional "version child classes" which are

tailbone/views/products.py

@@ -187,27 +187,12 @@ class ProductView(MasterView):
         self.handler = self.products_handler
 
     def query(self, session):
-        user = self.request.user
-        if user and user not in session:
-            user = session.merge(user)
+        query = super(ProductView, self).query(session)
 
-        query = session.query(model.Product)
-        # TODO: was this old `has_permission()` call here for a reason..? hope not..
-        # if not auth.has_permission(session, user, 'products.view_deleted'):
-        if not self.request.has_perm('products.view_deleted'):
+        if not self.has_perm('view_deleted'):
             query = query.filter(model.Product.deleted == False)
 
-        # TODO: This used to be a good idea I thought...but in dev it didn't
-        # seem to make much difference, except with a larger (50K) data set it
-        # totally bogged things down instead of helping...
-        # query = query\
-        #     .options(orm.joinedload(model.Product.brand))\
-        #     .options(orm.joinedload(model.Product.department))\
-        #     .options(orm.joinedload(model.Product.subdepartment))\
-        #     .options(orm.joinedload(model.Product.regular_price))\
-        #     .options(orm.joinedload(model.Product.current_price))\
-        #     .options(orm.joinedload(model.Product.vendor))
-
+        # TODO: surely this is not always needed
         query = query.outerjoin(model.ProductInventory)
 
         return query
@@ -1190,6 +1175,7 @@ class ProductView(MasterView):
         return jsdata
 
     def template_kwargs_view(self, **kwargs):
+        kwargs = super(ProductView, self).template_kwargs_view(**kwargs)
         product = kwargs['instance']
         use_buefy = self.get_use_buefy()