Introduced slots

force_bdss/core/slot.py

+from traits.api import HasStrictTraits, String
+
+
+class Slot(HasStrictTraits):
+    """Describes an input or output slot in the DataSource or
+    KPICalculator"""
+    #: A textual description of the slot
+    description = String("No description")
+
+    #: The CUBA key of the slot
+    type = String()

force_bdss/core/tests/test_slot.py

+import unittest
+
+from force_bdss.core.slot import Slot
+
+
+class TestSlot(unittest.TestCase):
+    def test_initialization(self):
+        slot = Slot()
+        self.assertEqual(slot.type, "")
+        self.assertEqual(slot.description, "No description")

force_bdss/core_plugins/dummy/csv_extractor/csv_extractor_data_source.py

 import csv
 from force_bdss.api import BaseDataSource, DataValue
+from force_bdss.core.slot import Slot
 
 
 class CSVExtractorDataSource(BaseDataSource):
@@ -20,3 +21,11 @@ class CSVExtractorDataSource(BaseDataSource):
                     break
 
             raise IndexError("Could not find specified data.")
+
+    def slots(self, model):
+        return (
+            (),
+            (
+                Slot(type=model.cuba_type),
+            )
+        )

force_bdss/core_plugins/dummy/dummy_data_source/dummy_data_source.py

@@ -4,3 +4,6 @@ from force_bdss.api import BaseDataSource
 class DummyDataSource(BaseDataSource):
     def run(self, model, parameters):
         return parameters
+
+    def slots(self, model):
+        return (), ()

force_bdss/core_plugins/dummy/dummy_kpi_calculator/dummy_kpi_calculator.py

@@ -4,3 +4,6 @@ from force_bdss.api import BaseKPICalculator
 class DummyKPICalculator(BaseKPICalculator):
     def run(self, model, data_source_results):
         return data_source_results
+
+    def slots(self, model):
+        return (), ()

force_bdss/core_plugins/dummy/kpi_adder/kpi_adder_calculator.py

 from force_bdss.api import BaseKPICalculator, DataValue
+from force_bdss.core.slot import Slot
 
 
 class KPIAdderCalculator(BaseKPICalculator):
@@ -16,3 +17,13 @@ class KPIAdderCalculator(BaseKPICalculator):
                 type=model.cuba_type_out,
                 value=sum
             )]
+
+    def slots(self, model):
+        return (
+            (
+                Slot(type=model.cuba_type_in),
+            ),
+            (
+                Slot(type=model.cuba_type_out),
+            )
+        )

force_bdss/data_sources/base_data_source.py

@@ -55,8 +55,14 @@ class BaseDataSource(ABCHasStrictTraits):
 
         Returns
         -------
-        list[tuple, tuple]
-            A list containing two tuples, the first element is the input slots,
-            the second element is the output slots. Each slot must be an
-            instance of the Slot class.
+        (input_slots, output_slots): tuple[tuple, tuple]
+            A tuple containing two tuples.
+            The first element is the input slots, the second element is
+            the output slots. Each slot must be an instance of the Slot class.
+            It is possible for each of the two inside tuples to be empty.
+            The case of an empty input slot is common: the DataSource does
+            not need any information from the MCO to operate.
+            The case of an empty output slot is uncommon, but supported:
+            the DataSource does not produce any output and is therefore
+            useless.
         """

force_bdss/data_sources/tests/test_base_data_source.py

@@ -13,6 +13,9 @@ class DummyDataSource(BaseDataSource):
     def run(self, *args, **kwargs):
         pass
 
+    def slots(self, model):
+        return (), ()
+
 
 class TestBaseDataSource(unittest.TestCase):
     def test_initialization(self):

force_bdss/kpi/base_kpi_calculator.py

@@ -38,3 +38,32 @@ class BaseKPICalculator(ABCHasStrictTraits):
         List[DataValue]:
             The result of this KPI evaluation, as a list of DataValues.
         """
+
+    @abc.abstractmethod
+    def slots(self, model):
+        """Returns the input (and output) slots of the KPI Calculator.
+        Slots are the entities that are needed (and produced) by this
+        KPI Calculator.
+
+        The slots may depend on the configuration options, and thus the model.
+        This allows, for example, to change the slots depending if an option
+        is enabled or not.
+
+        Parameters
+        ----------
+        model: BaseKPICalculatorModel
+            The model of the KPICalculator, instantiated through create_model()
+
+        Returns
+        -------
+        (input_slots, output_slots): tuple[tuple, tuple]
+            A tuple containing two tuples.
+            The first element is the input slots, the second element is
+            the output slots. Each slot must be an instance of the Slot class.
+            It is possible for each of the two inside tuples to be empty.
+            The case of an empty input slot is common: the KPICalculator does
+            not need any information from the MCO to operate.
+            The case of an empty output slot is uncommon, but supported:
+            the KPICalculator does not produce any output and is therefore
+            useless.
+        """

force_bdss/kpi/tests/test_base_kpi_calculator.py

@@ -12,6 +12,9 @@ class DummyKPICalculator(BaseKPICalculator):
     def run(self, *args, **kwargs):
         pass
 
+    def slots(self, model):
+        return (), ()
+
 
 class TestBaseKPICalculator(unittest.TestCase):
     def test_initialization(self):

force_bdss/tests/test_core_evaluation_driver.py

@@ -80,6 +80,9 @@ class NullKPICalculator(BaseKPICalculator):
     def run(self, model, data_source_results):
         return []
 
+    def slots(self, model):
+        return (), ()
+
 
 class NullKPICalculatorBundle(BaseKPICalculatorBundle):
     def create_model(self, model_data=None):
@@ -97,6 +100,9 @@ class NullDataSource(BaseDataSource):
     def run(self, model, parameters):
         return []
 
+    def slots(self, model):
+        return (), ()
+
 
 class NullDataSourceBundle(BaseDataSourceBundle):
     def create_model(self, model_data=None):