Add support for material property groups. (#90)

As pointed out in issue #78, the material property groups, such as
"Basic" for the material "medium 1" in the demo model, did not show up
in the model tree as displayed by `mph.tree()`. We also could not
access those properties via the `Node.property()` method.

We fix that by also considering "property groups" (in addition to
"feature groups") as Java containers for children of a given node
when traversing the model tree.

mph/node.py

@@ -215,7 +215,12 @@ def java(self):
         java = parent.java
         if not java:
             return None
-        container = java if parent.is_group() else java.feature()
+        if parent.is_group():
+            container = java
+        elif hasattr(java, 'propertyGroup'):
+            container = java.propertyGroup()
+        else:
+            container = java.feature()
         for tag in container.tags():
             member = container.get(tag)
             if name == escape(member.label()):
@@ -260,6 +265,9 @@ def children(self):
             return [self.__class__(self.model, group) for group in self.groups]
         elif self.is_group():
             return [self/escape(java.get(tag).label()) for tag in java.tags()]
+        elif hasattr(java, 'propertyGroup'):
+            return [self/escape(java.propertyGroup(tag).label())
+                    for tag in java.propertyGroup().tags()]
         elif hasattr(java, 'feature'):
             return [self/escape(java.feature(tag).label())
                     for tag in java.feature().tags()]
@@ -579,6 +587,8 @@ def create(self, *arguments, name=None):
                 container = java.feature()
             elif hasattr(java, 'uniquetag') and hasattr(java, 'create'):
                 container = java
+        elif hasattr(java, 'propertyGroup'):
+            container = java.propertyGroup()
         elif hasattr(java, 'feature'):
             container = java.feature()
         if not hasattr(container, 'uniquetag'):
@@ -635,7 +645,13 @@ def remove(self):
             log.error(error)
             raise LookupError(error)
         parent = self.parent()
-        container = parent.java if parent.is_group() else parent.java.feature()
+        java = parent.java
+        if parent.is_group():
+            container = java
+        elif hasattr(java, 'propertyGroup'):
+            container = java.propertyGroup()
+        else:
+            container = java.feature()
         container.remove(self.java.tag())
 
 

tests/fixtures.py

@@ -62,5 +62,6 @@ def setup_logging():
         return
     logging.setLogRecordFactory(timed_records)
     logging.basicConfig(
-        level   = logging.DEBUG,
-        format  = '[%(timestamp)s] %(message)s')
+        level  = logging.DEBUG,
+        format = '[%(timestamp)s] %(message)s',
+    )

tests/test_node.py

@@ -365,6 +365,10 @@ def test_property():
     assert plot.property('plotonsecyaxis') == new
     plot.property('plotonsecyaxis', old)
     assert plot.property('plotonsecyaxis') == old
+    # Test changing material properties.
+    assert (material/'Basic').property('relpermittivity') == ['1']
+    (material/'Basic').property('relpermittivity', 2)
+    assert (material/'Basic').property('relpermittivity') == ['2']
     # Read and write back every node property in the model.
     if not client.port:
         # Skip test in client-server mode where it's excruciatingly slow.
@@ -485,6 +489,11 @@ def test_create():
             Node(model, '').create()
         with raises(RuntimeError):
             Node(model, 'components/component').create()
+    material = Node(model, 'materials/medium 1')
+    material.create('custom', name='custom')
+    assert (material/'custom').exists()
+    (material/'custom').property('bulkviscosity', '1')
+    assert (material/'custom').property('bulkviscosity') == '1'
 
 
 def test_remove():
@@ -498,6 +507,9 @@ def test_remove():
     physics = Node(model, 'physics')
     (physics/'Electrostatics 1').remove()
     assert not (physics/'Electrostatics 1').exists()
+    material = Node(model, 'materials/medium 1')
+    (material/'custom').remove()
+    assert not (material/'custom').exists()
     with logging_disabled():
         with raises(PermissionError):
             Node(model, '').remove()
@@ -584,28 +596,38 @@ def test_tree():
     with capture_stdout() as output:
         mph.tree(model, max_depth=1)
     expected = '''
-    capacitor
-    ├─ parameters
-    ├─ functions
-    ├─ components
-    ├─ geometries
-    ├─ views
-    ├─ selections
-    ├─ coordinates
-    ├─ variables
-    ├─ couplings
-    ├─ physics
-    ├─ multiphysics
-    ├─ materials
-    ├─ meshes
-    ├─ studies
-    ├─ solutions
-    ├─ batches
-    ├─ datasets
-    ├─ evaluations
-    ├─ tables
-    ├─ plots
-    └─ exports
+        capacitor
+        ├─ parameters
+        ├─ functions
+        ├─ components
+        ├─ geometries
+        ├─ views
+        ├─ selections
+        ├─ coordinates
+        ├─ variables
+        ├─ couplings
+        ├─ physics
+        ├─ multiphysics
+        ├─ materials
+        ├─ meshes
+        ├─ studies
+        ├─ solutions
+        ├─ batches
+        ├─ datasets
+        ├─ evaluations
+        ├─ tables
+        ├─ plots
+        └─ exports
+    '''
+    assert output.text().strip() == dedent(expected).strip()
+    with capture_stdout() as output:
+        mph.tree(model/'materials')
+    expected = '''
+        materials
+        ├─ medium 1
+        │  └─ Basic
+        └─ medium 2
+           └─ Basic
     '''
     assert output.text().strip() == dedent(expected).strip()