Fix/new space (#203)

modelx/core/model.py

@@ -36,7 +36,7 @@
     EditableParent,
 )
 from modelx.core.space import UserSpaceImpl
-from modelx.core.binding.namespace import BaseNamespace
+from modelx.core.binding.namespace import BaseNamespace, NamespaceServer
 from modelx.core.formula import NULL_FORMULA
 from modelx.core.util import is_valid_name
 from modelx.core.execution.trace import TraceManager
@@ -1802,10 +1802,8 @@ def new_space(
             formula=None,
             refs=None,
             source=None,
-            is_derived=False,
             prefix="",
-            doc=None,
-            container=None
+            doc=None
     ):
         """Create a new child space.
 
@@ -1862,18 +1860,19 @@ def new_space(
         for n in nx.descendants(self._graph, node):
             self._graph.get_mro(n)
 
-        if container is None:
-            container = parent.named_spaces
-
         space = UserSpaceImpl(
             parent,
             name,
-            container,
+            container=parent.named_spaces,
             formula=formula,
             refs=refs,
             source=source,
             doc=doc
         )
+
+        if isinstance(parent, NamespaceServer):
+            parent.on_notify(parent.named_spaces)   # Fix: bug GH203
+
         self._graph.nodes[node]["space"] = space
         self._graph.nodes[node]["state"] = "created"
 
@@ -1886,7 +1885,7 @@ def new_space(
         try:
             self._instructions.execute()
         except BaseException:
-            del container[name]
+            del parent.named_spaces[name]
             raise
 
         self._update_manager()
@@ -2030,10 +2029,8 @@ def _copy_space_recursively(
             formula=source.formula,
             refs={k: v.interface for k, v in source.own_refs.items()},
             source=source.source,
-            is_derived=False,
             prefix="",
-            doc=source.doc,
-            container=None
+            doc=source.doc
         )
 
         for cells in source.cells.values():

modelx/tests/core/space/test_new_space.py

@@ -0,0 +1,21 @@
+import modelx as mx
+
+
+def test_new_space_when_parent_has_itemspace():
+
+    # https://github.com/fumitoh/modelx/issues/203
+
+    m = mx.new_model()
+    space = m.new_space()
+    space.parameters = ('x', )
+    space[1]    # create an itemspace
+
+    assert 1 in space.itemspaces
+    space.new_space('SpaceA')
+
+    assert not space.itemspaces     # must be empty
+    assert 'SpaceA' in dir(space)   # must have SpaceA in its namespace
+
+
+
+