Add _MockPropertyFieldsContainer class (#1033)

* Move PropertyFieldsContainer from Post PR to Core

* Move PropertyFieldsContainer from Post PR to Core

* Add testing

* Improve coverage

* Fix retro

* Rename to _MockPropertyFieldsContainer

* Ignore property_fields_container.py on API doc generation

* Remove unnecessary methods

* Improve typehinting

* Put back _MockPropertyFieldsContainer.rescope as it is used by post.Dataframe.select

* Fix retro

* Add back _set_field

.ci/build_doc.bat

@@ -4,7 +4,7 @@ call sphinx-apidoc -o ../docs/source/api ../src/ansys ../src/ansys/dpf/core/log.
 ../src/ansys/dpf/core/field_base.py ../src/ansys/dpf/core/cache.py ../src/ansys/dpf/core/misc.py ^
 ../src/ansys/dpf/core/check_version.py ../src/ansys/dpf/core/operators/build.py ../src/ansys/dpf/core/operators/specification.py ^
 ../src/ansys/dpf/core/vtk_helper.py ../src/ansys/dpf/core/label_space.py ../src/ansys/dpf/core/examples/python_plugins/* ^
-../src/ansys/dpf/core/examples/examples.py ^
+../src/ansys/dpf/core/examples/examples.py ../src/ansys/dpf/core/property_fields_container.py ^
  -f --implicit-namespaces --separate  --no-headings
 pushd .
 cd ../docs/

src/ansys/dpf/core/property_fields_container.py

@@ -0,0 +1,226 @@
+"""
+.. _ref_property_fields_container:
+
+_MockPropertyFieldsContainer
+============================
+Contains classes associated with the _MockPropertyFieldsContainer.
+"""
+from __future__ import annotations
+
+from collections.abc import Sequence
+import copy
+from typing import Dict, List, Union
+
+import numpy as np
+
+import ansys.dpf.core as dpf
+from ansys.dpf.core import PropertyField
+from ansys.dpf.core.server_types import BaseServer
+
+
+class _LabelSpaceKV:
+    """Class for internal use to associate a label space with a field."""
+
+    def __init__(self, _dict: Dict[str, int], _field: dpf.Field):
+        """Constructs an association between a dictionary and a field."""
+        self._dict = _dict
+        self._field = _field
+
+    @property
+    def dict(self) -> dict:
+        """Returns the associated dictionary."""
+        return self._dict
+
+    @property
+    def field(self) -> dpf.Field:
+        """Returns the associated field."""
+        return self._field
+
+    @field.setter
+    def field(self, value: dpf.Field):
+        self._field = value
+
+    def __str__(self):
+        """Returns a string representation of the association."""
+        field_str = str(self._field).replace("\n", "\n\t\t\t")
+        return f"Label Space: {self._dict} with field\n\t\t\t{field_str}"
+
+
+class _MockPropertyFieldsContainer(Sequence):
+    """Minimal implementation of a FieldsContainer specialized for _MockPropertyFieldsContainer."""
+
+    def __init__(
+        self,
+        fields_container: _MockPropertyFieldsContainer = None,
+        server: BaseServer = None,
+    ):
+        """Constructs a _MockPropertyFieldsContainer."""
+        # default constructor
+        self._labels = []  # used by Dataframe
+        self.scopings = []
+        self._server = None  # used by Dataframe
+
+        self.label_spaces = []
+        self.ids = []
+
+        # _MockPropertyFieldsContainer copy
+        if fields_container is not None:
+            self._labels = copy.deepcopy(fields_container.labels)
+            # self.scopings = copy.deepcopy(fields_container.scopings)
+            self._server = fields_container._server
+
+            # self.ids = copy.deepcopy(fields_container.ids)
+
+            for ls in fields_container.label_spaces:
+                self.add_entry(copy.deepcopy(ls.dict), ls.field.as_local_field())
+
+        # server copy
+        if server is not None:
+            self._server = server
+
+    # Collection
+    def __str__(self) -> str:
+        """Returns a string representation of a _MockPropertyFieldsContainer."""
+        txt = f"DPF PropertyFieldsContainer with {len(self)} fields\n"
+        for idx, ls in enumerate(self.label_spaces):
+            txt += f"\t {idx}: {ls}\n"
+
+        return txt
+
+    @property
+    def labels(self) -> List[str]:
+        """Returns all labels of the _MockPropertyFieldsContainer."""
+        return self._labels
+
+    @labels.setter
+    def labels(self, labels: List[str]):
+        """Sets all the label of the _MockPropertyFieldsContainer."""
+        if len(self._labels) != 0:
+            raise ValueError("labels already set")
+        for l in labels:
+            self.add_label(l)
+
+    def add_label(self, label: str):
+        """Adds a label."""
+        if label not in self._labels:
+            self._labels.append(label)
+            self.scopings.append([])
+
+    def has_label(self, label) -> bool:
+        """Check if a _MockPropertyFieldsContainer contains a given label."""
+        return label in self.labels
+
+    # used by Dataframe
+    def get_label_space(self, idx) -> Dict:
+        """Get a Label Space at a given index."""
+        return self.label_spaces[idx].dict
+
+    # used by Dataframe
+    def get_label_scoping(self, label="time") -> dpf.Scoping:
+        """Returns a scoping on the fields concerned by the given label."""
+        if label in self.labels:
+            scoping_ids = self.scopings[self.labels.index(label)]
+            return dpf.Scoping(ids=scoping_ids, location="")
+        raise KeyError(f"label {label} not found")
+
+    def add_entry(self, label_space: Dict[str, int], value: dpf.Field):
+        """Adds a PropertyField associated with a dictionary."""
+        new_id = self._new_id()
+
+        if hasattr(value, "_server"):
+            self._server = value._server
+
+        # add Label Space
+        self.label_spaces.append(_LabelSpaceKV(label_space, value))
+
+        # Update IDs
+        self.ids.append(new_id)
+
+        # Update Scopings
+        for label in label_space.keys():
+            label_idx = self.labels.index(label)
+            self.scopings[label_idx].append(new_id)
+
+    def add_field(self, label_space: Dict[str, int], field: dpf.Field):
+        """Add or update a field at a requested label space."""
+        self.add_entry(label_space, field)
+
+    def get_entries(self, label_space_or_index: Union[Dict[str, int], int]):
+        """Returns a list of fields from a complete or partial specification of a dictionary."""
+        if isinstance(label_space_or_index, int):
+            idx: int = label_space_or_index
+            return [self.label_spaces[idx].field]
+        else:
+            _dict: Dict[str, int] = label_space_or_index
+            are_keys_in_labels = [key in self.labels for key in _dict.keys()]
+            if all(are_keys_in_labels):
+                remaining = set(range(len(self.label_spaces)))
+                for key in _dict.keys():
+                    val = _dict[key]
+                    to_remove = set()
+                    for idx in remaining:
+                        ls = self.label_spaces[idx]
+                        if key in ls.dict.keys():
+                            if ls.dict[key] != val:
+                                to_remove.add(idx)
+                        else:
+                            to_remove.add(idx)
+                    remaining = remaining.difference(to_remove)
+
+                idx_to_field = lambda idx: self.label_spaces[idx].field
+                return list(map(idx_to_field, remaining))
+            else:
+                bad_idx = are_keys_in_labels.index(False)
+                bad_key = list(_dict.keys())[bad_idx]
+                raise KeyError(f"Key {bad_key} is not in labels: {self.labels}")
+
+    def get_entry(self, label_space_or_index: Union[Dict[str, int], int]):
+        """Returns the field or (first field found) corresponding to the given dictionary."""
+        ret = self.get_entries(label_space_or_index)
+
+        if len(ret) != 0:
+            return ret[0]
+
+        raise ValueError("Could not find corresponding entry")
+
+    def _new_id(self) -> int:
+        """Helper method generating a new id when calling add_entry(...)."""
+        if len(self.ids) == 0:
+            self.last_id = 1
+            return self.last_id
+        else:
+            self.last_id += 1
+            return self.last_id
+
+    # used by Dataframe
+    def get_fields(self, label_space: Dict[str, int]) -> List[dpf.Field]:
+        """Returns the list of fields associated with given label space."""
+        return self.get_entries(label_space)
+
+    def get_field(self, label_space_or_index: Union[Dict[str, int], int]) -> dpf.Field:
+        """Retrieves the field at a requested index or label space."""
+        return self.get_entry(label_space_or_index)
+
+    # used by Dataframe
+    def __getitem__(self, key: Union[Dict[str, int], int]) -> dpf.Field:
+        """Retrieve the field at a requested index."""
+        return self.get_field(key)
+
+    def __len__(self) -> int:
+        """Retrieve the number of label spaces."""
+        return len(self.label_spaces)
+
+    def _set_field(self, ls_idx, field):
+        self.label_spaces[ls_idx].field = field
+
+    def rescope(self, scoping: dpf.Scoping):  # Used by post.Dataframe
+        """Helper function to reproduce functionality of rescope_fc Operator."""
+        copy_fc = _MockPropertyFieldsContainer(self, server=None)
+        for idx, label_space in enumerate(copy_fc.label_spaces):
+            pfield = PropertyField(location=label_space.field.location)
+            pfield.data = np.ravel(
+                [label_space._field.get_entity_data_by_id(id) for id in scoping.ids]
+            )
+            pfield.scoping.ids = scoping.ids
+            copy_fc._set_field(idx, pfield)
+        return copy_fc

tests/test_property_fields_container.py

@@ -0,0 +1,47 @@
+import pytest
+
+from ansys.dpf.core.property_fields_container import _MockPropertyFieldsContainer, _LabelSpaceKV
+from ansys.dpf import core as dpf
+
+
+def test_property_fields_container(allkindofcomplexity, server_type):
+    model = dpf.Model(allkindofcomplexity, server=server_type)
+    fields_container = _MockPropertyFieldsContainer(server=server_type)
+    fields_container.add_label(label="test")
+    assert fields_container.has_label(label="test")
+    assert fields_container.labels == ["test"]
+    with pytest.raises(ValueError, match="labels already set"):
+        fields_container.labels = ["test"]
+    field = model.metadata.meshed_region.elements.connectivities_field
+    fields_container.add_field(label_space={"test": 42}, field=field)
+    assert len(fields_container.label_spaces) == 1
+    label_space = fields_container.label_spaces[0]
+    assert fields_container.get_label_space(0) == {"test": 42}
+    assert isinstance(label_space, _LabelSpaceKV)
+    assert label_space.field == field
+    assert label_space.dict == {"test": 42}
+    label_space.field = model.metadata.meshed_region.elements.element_types_field
+    ref = """DPF PropertyFieldsContainer with 1 fields
+\t 0: Label Space: {'test': 42} with field
+\t\t\t"""  # noqa
+    assert ref in str(fields_container)
+    with pytest.raises(KeyError, match="label test2 not found"):
+        fields_container.get_label_scoping("test2")
+    scoping = fields_container.get_label_scoping("test")
+    assert isinstance(scoping, dpf.Scoping)
+    assert scoping.ids == [1]
+    assert scoping.location == ""
+
+    property_field = fields_container.get_entries(0)[0]
+    assert isinstance(property_field, dpf.property_field.PropertyField)
+    assert fields_container.get_entries({"test": 42})[0] == property_field
+    with pytest.raises(KeyError, match="is not in labels:"):
+        fields_container.get_entries(({"test2": 0}))
+    assert fields_container.get_entry({"test": 42}) == property_field
+    with pytest.raises(ValueError, match="Could not find corresponding entry"):
+        fields_container.get_entry(({"test": 0}))
+    assert fields_container[{"test": 42}] == property_field
+    assert len(fields_container) == 1
+
+    assert fields_container.get_fields({"test": 42})[0] == property_field
+    assert fields_container.get_field(0) == property_field