aas.examples: create formulas

check formulas for equality in data checker
close #66

aas/examples/data/_helper.py

@@ -183,13 +183,16 @@ class AASDataChecker(DataChecker):
         :param expected_object: The expected qualifiable object
         :return: The value of expression to be used in control statements
         """
-        # TODO add check of formula => not clear how to identify a formula
         self.check_contained_element_length(object_, 'qualifier', model.Constraint, len(expected_object.qualifier))
         for expected_element in expected_object.qualifier:
             element = self._find_element_by_attribute(expected_element, object_.qualifier, 'type')
             if self.check(element is not None, 'Constraint{} must exist'.format(repr(expected_element))):
-                self._check_qualifier_equal(element, expected_element)  # type: ignore
-
+                if isinstance(element, model.Formula):
+                    self._check_formula_equal(element, expected_element)  # type: ignore
+                elif isinstance(element, model.Qualifier):
+                    self._check_qualifier_equal(element, expected_element)  # type: ignore
+                else:
+                    raise TypeError('Constraint class not implemented')
         found_elements = self._find_extra_elements_by_attribute(object_.qualifier, expected_object.qualifier, 'type')
         self.check(found_elements == set(), 'Qualifiable Element {} must not have extra elements'.format(repr(object_)),
                    value=found_elements)
@@ -594,6 +597,19 @@ class AASDataChecker(DataChecker):
         self.check_attribute_equal(object_, 'value', expected_value.value)
         self.check_attribute_equal(object_, 'value_id', expected_value.value_id)
 
+    def _check_formula_equal(self, object_: model.Formula, expected_value: model.Formula):
+        """
+        Checks if the given Formula objects are equal
+
+        :param object_: Given Formula object to check
+        :param expected_value: expected Formula object
+        :return:
+        """
+        for expected_ref in expected_value.depends_on:
+            ref = self._find_reference(expected_ref, object_.depends_on)
+            if self.check(ref is not None, 'Reference {} must exist'.format(repr(expected_ref))):
+                self._check_reference_equal(ref, expected_ref)  # type: ignore
+
     def check_asset_equal(self, object_: model.Asset, expected_value: model.Asset):
         """
         Checks if the given Asset objects are equal

aas/examples/data/example_aas.py

@@ -161,7 +161,12 @@ def create_example_bill_of_material_submodel() -> model.Submodel:
                                                local=False,
                                                value='http://acplt.org/Properties/ExampleProperty',
                                                id_type=model.KeyType.IRI),)),
-        qualifier=None,
+        qualifier={model.Formula(
+            depends_on={model.Reference((model.Key(type_=model.KeyElements.GLOBAL_REFERENCE,
+                                                   local=False,
+                                                   value='http://acplt.org/ValueId/ExampleValueId',
+                                                   id_type=model.KeyType.IRI),))}),
+                   model.Formula()},
         kind=model.ModelingKind.INSTANCE)
 
     submodel_element_property2 = model.Property(