Refactor "edit printer settings" view for Label Profile

for sake of Buefy, but it was definitely using some old form patterns...

tailbone/forms/core.py

@@ -37,6 +37,7 @@ from sqlalchemy.ext.associationproxy import AssociationProxy, ASSOCIATION_PROXY
 
 from rattail.time import localtime
 from rattail.util import prettify, pretty_boolean, pretty_hours, pretty_quantity
+from rattail.core import UNSPECIFIED
 
 import colander
 import deform
@@ -338,7 +339,7 @@ class Form(object):
     auto_disable_cancel = True
 
     def __init__(self, fields=None, schema=None, request=None, mobile=False, readonly=False, readonly_fields=[],
-                 model_instance=None, model_class=None, nodes={}, enums={}, labels={}, renderers=None,
+                 model_instance=None, model_class=None, appstruct=UNSPECIFIED, nodes={}, enums={}, labels={}, renderers=None,
                  hidden={}, widgets={}, defaults={}, validators={}, required={}, helptext={}, focus_spec=None,
                  action_url=None, cancel_url=None, use_buefy=None):
 
@@ -358,6 +359,7 @@ class Form(object):
             self.model_class = type(self.model_instance)
         if self.model_class and self.fields is None:
             self.set_fields(self.make_fields())
+        self.appstruct = appstruct
         self.nodes = nodes or {}
         self.enums = enums or {}
         self.labels = labels or {}
@@ -706,7 +708,12 @@ class Form(object):
 
             # get initial form values from model instance
             kwargs = {}
-            if self.model_instance:
+            # TODO: ugh, this is necessary to avoid some logic
+            # which assumes a ColanderAlchemy schema i think?
+            if self.appstruct is not UNSPECIFIED:
+                if self.appstruct:
+                    kwargs['appstruct'] = self.appstruct
+            elif self.model_instance:
                 if self.model_class:
                     kwargs['appstruct'] = schema.dictify(self.model_instance)
                 else: