incorprorate review comments

CHANGES.rst

@@ -2,6 +2,8 @@
 ===================
 - Fix Node assignment issues. [#275]
 
+- Fix newly required units from rand [#256]
+
 - Update minimum version of astropy to 5.3.0 in order to fix a bug due to a breaking
   change in astropy. [#258]
 

docs/roman_datamodels/datamodels/using_datamodels.rst

@@ -101,17 +101,11 @@ page::
     There are a couple subtlties with regard to changing values in a datamodel.
     If you assign dicts or lists to attributes, it will map these into the
     corresponding DNode or LNode subclasses. In such uses, the assigned values 
-    will be immediately be checked by validating against the defining schemas.
+    will be immediately checked by validating against the defining schemas.
     When the value being assigned fails to pass that validation, an exception
     will occur. This is generally a good thing, particularly if you are changing
     values interactively
 
-    On the other hand, if one assigns to the attribute a subclass of DNode
-    or LNode, no immediate validation is done (for current implenentation
-    reasons). If the wrong kind of DNode or LNode is assigned to the 
-    attribute that doesn't match the expected tag for that attribute, the error
-    will only be raised when trying to write the file to disk.
-
 	If you are getting validation errors consult the corresponding schema in
 	``rad`` to se what is allowed. If you think the schema is wrong, or you
 	continue to have issues, please contact the Roman team for help.

src/roman_datamodels/stnode/_converters.py

@@ -114,50 +114,9 @@ def from_yaml_tree(self, node, tag, ctx):
 
         return SCALAR_NODE_CLASSES_BY_TAG[tag](node)
 
-# The following converters are intended allow the current node behavior of
-# accessing node attributes that are simple lists and dicts and returning
-# them as LNode and DNode instances so that the attribute machinery works
-# (i.e., that it is possible to access dict members as attributes rather
-# than requiring the usual index syntax). This presents a problem with
-# assigning such instances where simple lists and dicts are expected (and
-# thus failing validation). This is solved by providing converters for
-# DNode and LNode that turn instances back to dicts and lists on serialization
-# so that they pass validation. Only conversion is needed for serialization,
-# and not for deserializing since there are no tags that can be used for
-# that.
-
-class DNodeConverter(Converter):
-    tags = []
-    types = ["roman_datamodels.stnode._node.DNode"]
-
-    def select_tag(self, obj, tags, ctx):
-        # return tags[0]
-        return None
-
-    def to_yaml_tree(self, obj, tag, ctx):
-        return obj._data
-
-    def from_yaml_tree(self, node, tag, ctx):
-        raise NotImplementedError()
-
-
-class LNodeConverter(Converter):
-    tags =[]
-    types = ["roman_datamodels.stnode._node.LNode"]
-
-    def select_tag(self, obj, tags, ctx):
-        # return tags[0]
-        return None
-
-    def to_yaml_tree(self, obj, tag, ctx):
-        return obj.data
-
-    def from_yaml_tree(self, node, tag, ctx):
-        raise NotImplementedError()
 
 # Create the ASDF extension for the STNode classes.
 NODE_EXTENSIONS = [
     ManifestExtension.from_uri("asdf://stsci.edu/datamodels/roman/manifests/datamodels-1.0",
         converters=NODE_CONVERTERS.values()),
-    ManifestExtension(None, converters=[DNodeConverter(), LNodeConverter()]),
 ]

src/roman_datamodels/stnode/_node.py

@@ -60,6 +60,10 @@ def _check_value(value, schema, validator_context):
 
 
 def _validate(attr, instance, schema, ctx):
+    if type(instance) == DNode:
+        instance = instance._data
+    elif type(instance) == LNode:
+        instance = instance.data
     tagged_tree = yamlutil.custom_tree_to_tagged_tree(instance, ctx)
     return _value_change(attr, tagged_tree, schema, False, will_strict_validate(), ctx)
 
@@ -148,7 +152,8 @@ def __setattr__(self, key, value):
             if key in self._data:
                 if will_validate():
                     schema = _get_schema_for_property(self._schema(), key)
-                    schema == {} or _validate(key, value, schema, self.ctx)
+                    if schema:
+                        _validate(key, value, schema, self.ctx)
                 self._data[key] = value
             else:
                 raise AttributeError(f"No such attribute ({key}) found in node")