[ci skip] Add a method 'EntityCell.mixed_populate_entities()'.

Author: genglert

creme/creme_core/core/entity_cell.py

@@ -19,7 +19,17 @@
 ################################################################################
 
 import logging
-from typing import Dict, Iterable, List, Optional, Tuple, Type  # Callable
+from collections import defaultdict
+from typing import (  # Callable
+    DefaultDict,
+    Dict,
+    Iterable,
+    List,
+    Optional,
+    Sequence,
+    Tuple,
+    Type,
+)
 
 from django.db import models
 from django.db.models import Field, FieldDoesNotExist, Model
@@ -179,7 +189,37 @@ def is_multiline(self) -> bool:
         return issubclass(self._get_field_class(), MULTILINE_FIELDS)
 
     @staticmethod
-    def populate_entities(cells, entities, user):
+    def mixed_populate_entities(cells: Iterable['EntityCell'],
+                                entities: Sequence[CremeEntity],
+                                user) -> None:
+        """Fill caches of CremeEntity objects with grouped SQL queries, & so
+        avoid multiple queries when rendering the cells.
+        The given cells are grouped by types, and then the method
+        'populate_entities()' of each used type is called.
+        @param cells: Instances of (subclasses of) EntityCell.
+        @param entities: Instances of CremeEntities (or subclass).
+        @param user: Instance of <contrib.auth.get_user_model()>.
+        """
+        cell_groups: DefaultDict[Type['EntityCell'], List['EntityCell']] = defaultdict(list)
+
+        for cell in cells:
+            cell_groups[cell.__class__].append(cell)
+
+        for cell_cls, cell_group in cell_groups.items():
+            cell_cls.populate_entities(cell_group, entities, user)
+
+    @staticmethod
+    def populate_entities(cells: Iterable['EntityCell'],
+                          entities: Sequence[CremeEntity],
+                          user) -> None:
+        """Fill caches of CremeEntity objects with grouped SQL queries, & so
+        avoid multiple queries when rendering the cells.
+        The given cells MUST HAVE THE SAME TYPE (corresponding to the class
+        the method belongs).
+        @param cells: Instances of (subclasses of) EntityCell.
+        @param entities: Instances of CremeEntities (or subclass).
+        @param user: Instance of <contrib.auth.get_user_model()>.
+        """
         pass
 
     # TODO: factorise render_* => like FunctionField, result that can be html, csv...

creme/creme_core/forms/header_filter.py

@@ -173,13 +173,18 @@ def sub_widgets(self, widgets: Iterable[UniformEntityCellsWidget]):
     def _build_samples(self) -> List[Dict[str, str]]:
         user = self.user
         samples = []
-
         cells = [*chain.from_iterable(sub_w.choices for sub_w in self._sub_widgets)]
+        entities = [
+            *EntityCredentials.filter(
+                user=user, queryset=self.model.objects.order_by('-modified'),
+            )[:2],
+        ]
+        EntityCell.mixed_populate_entities(
+            cells=[choice[1] for choice in cells],
+            entities=entities, user=user,
+        )
 
-        # TODO: populate entities
-        for entity in EntityCredentials.filter(
-            user, self.model.objects.order_by('-modified'),
-        )[:2]:
+        for entity in entities:
             dump = {}
 
             for choice_id, cell in cells:

creme/creme_core/models/header_filter.py

@@ -20,11 +20,10 @@
 
 import logging
 # import warnings
-from collections import defaultdict
+# from collections import defaultdict
 from json import loads as json_load
-from typing import (
+from typing import (  # DefaultDict
     TYPE_CHECKING,
-    DefaultDict,
     Iterable,
     List,
     Optional,
@@ -318,19 +317,21 @@ def get_edit_absolute_url(self):
     #         )
     #     )
 
-    # TODO: dispatch this job in Cells classes
-    #       => get the cells as argument, so we can pass filtered cells
     # TODO: way to mean QuerySet[CremeEntity] ??
     def populate_entities(self, entities: QuerySet, user) -> None:
         """Fill caches of CremeEntity objects, related to the columns that will
         be displayed with this HeaderFilter.
         @param entities: QuerySet on CremeEntity (or subclass).
         @param user: Instance of get_user_model().
         """
-        cell_groups: DefaultDict[Type['EntityCell'], List['EntityCell']] = defaultdict(list)
-
-        for cell in self.cells:
-            cell_groups[cell.__class__].append(cell)
-
-        for cell_cls, cell_group in cell_groups.items():
-            cell_cls.populate_entities(cell_group, entities, user)
+        # cell_groups: DefaultDict[Type['EntityCell'], List['EntityCell']] = defaultdict(list)
+        #
+        # for cell in self.cells:
+        #     cell_groups[cell.__class__].append(cell)
+        #
+        # for cell_cls, cell_group in cell_groups.items():
+        #     cell_cls.populate_entities(cell_group, entities, user)
+        from ..core.entity_cell import EntityCell
+        EntityCell.mixed_populate_entities(
+            cells=self.cells, entities=entities, user=user,
+        )

creme/creme_core/tests/core/test_entity_cell.py

@@ -26,12 +26,16 @@
     function_field_registry,
 )
 from creme.creme_core.models import (
+    CremeEntity,
     CustomField,
     CustomFieldEnumValue,
+    FakeCivility,
     FakeContact,
     FakeDocument,
     FakeFolder,
+    FakePosition,
     FieldsConfig,
+    Relation,
     RelationType,
 )
 
@@ -597,3 +601,151 @@ def __init__(self, model, value):
             TestCell(model=FakeDocument, value='title'),
             cell1
         )
+
+    def test_mixed_populate_entities01(self):
+        "Regular fields: no FK."
+        user = self.create_user()
+
+        pos = FakePosition.objects.create(title='Pilot')
+        create_contact = partial(FakeContact.objects.create, user=user, position_id=pos.id)
+        contacts = [
+            create_contact(first_name='Nagate',  last_name='Tanikaze'),
+            create_contact(first_name='Shizuka', last_name='Hoshijiro'),
+        ]
+
+        build = partial(EntityCellRegularField.build, model=FakeContact)
+        cells = [build(name='last_name'), build(name='first_name')]
+
+        with self.assertNumQueries(0):
+            EntityCell.mixed_populate_entities(cells=cells, entities=contacts, user=user)
+
+        with self.assertNumQueries(1):
+            contacts[0].position  # NOQA
+
+    def test_mixed_populate_entities02(self):
+        "Regular fields: FK."
+        user = self.create_user()
+
+        pos = FakePosition.objects.all()[0]
+        civ = FakeCivility.objects.all()[0]
+        create_contact = partial(
+            FakeContact.objects.create, user=user, position=pos, civility=civ,
+        )
+        contact1 = create_contact(first_name='Nagate', last_name='Tanikaze')
+        contact2 = create_contact(first_name='Shizuka', last_name='Hoshijiro')
+        # NB: we refresh because the __str__() method retrieves the civility
+        contacts = [self.refresh(contact1), self.refresh(contact2)]
+
+        build = partial(EntityCellRegularField.build, model=FakeContact)
+        cells = [
+            build(name='last_name'), build(name='first_name'),
+            build(name='position'),
+            build(name='civility__title'),
+        ]
+
+        with self.assertNumQueries(2):
+            EntityCell.mixed_populate_entities(cells=cells, entities=contacts, user=user)
+
+        with self.assertNumQueries(0):
+            contacts[0].position  # NOQA
+            contacts[1].position  # NOQA
+            contacts[0].civility  # NOQA
+            contacts[1].civility  # NOQA
+
+    def test_mixed_populate_entities03(self):
+        "Relationships."
+        user = self.create_user()
+
+        create_rt = RelationType.create
+        loved = create_rt(
+            ('test-subject_love', 'Is loving'),
+            ('test-object_love', 'Is loved by'),
+        )[1]
+        hated = create_rt(
+            ('test-subject_hate', 'Is hating'),
+            ('test-object_hate', 'Is hated by'),
+        )[1]
+
+        cells = [
+            EntityCellRegularField.build(model=FakeContact, name='last_name'),
+            EntityCellRelation(model=FakeContact, rtype=loved),
+            EntityCellRelation(model=FakeContact, rtype=hated),
+        ]
+
+        create_contact = partial(FakeContact.objects.create, user=user)
+        nagate  = create_contact(first_name='Nagate',  last_name='Tanikaze')
+        shizuka = create_contact(first_name='Shizuka', last_name='Hoshijiro')
+        izana   = create_contact(first_name='Izana',   last_name='Shinatose')
+        norio   = create_contact(first_name='Norio',   last_name='Kunato')
+
+        create_rel = partial(Relation.objects.create, user=user)
+        create_rel(subject_entity=nagate,  type=loved, object_entity=izana)
+        create_rel(subject_entity=nagate,  type=hated, object_entity=norio)
+        create_rel(subject_entity=shizuka, type=loved, object_entity=norio)
+
+        # NB: sometimes a query to get this CT is performed when the Relations
+        # are retrieved. So we force the cache to be filled has he should be
+        ContentType.objects.get_for_model(CremeEntity)
+
+        with self.assertNumQueries(2):
+            EntityCell.mixed_populate_entities(cells, [nagate, shizuka], user)
+
+        with self.assertNumQueries(0):
+            r1 = nagate.get_relations(loved.id,  real_obj_entities=True)
+            r2 = nagate.get_relations(hated.id,  real_obj_entities=True)
+            r3 = shizuka.get_relations(loved.id, real_obj_entities=True)
+            r4 = shizuka.get_relations(hated.id, real_obj_entities=True)
+
+        with self.assertNumQueries(0):
+            objs1 = [r.object_entity.get_real_entity() for r in r1]
+            objs2 = [r.object_entity.get_real_entity() for r in r2]
+            objs3 = [r.object_entity.get_real_entity() for r in r3]
+            objs4 = [r.object_entity.get_real_entity() for r in r4]
+
+        self.assertListEqual([izana], objs1)
+        self.assertListEqual([norio], objs2)
+        self.assertListEqual([norio], objs3)
+        self.assertListEqual([],      objs4)
+
+    def test_mixed_populate_entities04(self):
+        "Mixed types."
+        user = self.create_user()
+
+        pos = FakePosition.objects.all()[0]
+        create_contact = partial(FakeContact.objects.create, user=user)
+        contacts = [
+            create_contact(first_name='Nagate',  last_name='Tanikaze', position=pos),
+            create_contact(first_name='Shizuka', last_name='Hoshijiro'),
+            create_contact(first_name='Izana',   last_name='Shinatose'),
+        ]
+
+        loved = RelationType.create(
+            ('test-subject_love', 'Is loving'),
+            ('test-object_love', 'Is loved by'),
+        )[1]
+        Relation.objects.create(
+            user=user, subject_entity=contacts[0], type=loved, object_entity=contacts[2],
+        )
+
+        build_rfield = partial(EntityCellRegularField.build, model=FakeContact)
+        cells = [
+            build_rfield(name='last_name'),
+            build_rfield(name='position'),
+            EntityCellRelation(model=FakeContact, rtype=loved),
+        ]
+
+        # NB: sometimes a query to get this CT is performed when the Relations
+        # are retrieved. So we force the cache to be filled has he should be
+        ContentType.objects.get_for_model(CremeEntity)
+
+        # Drop caches
+        contacts = [self.refresh(c) for c in contacts]
+
+        with self.assertNumQueries(3):
+            EntityCell.mixed_populate_entities(cells, contacts, user)
+
+        with self.assertNumQueries(0):
+            contacts[0].position  # NOQA
+
+        with self.assertNumQueries(0):
+            contacts[0].get_relations(loved.id,  real_obj_entities=True)