Replaces most of the backrefs with explicit relationships

src/onegov/election_day/models/data_source.py

@@ -9,7 +9,6 @@
 from sqlalchemy import Enum
 from sqlalchemy import ForeignKey
 from sqlalchemy import Text
-from sqlalchemy.orm import backref
 from sqlalchemy.orm import object_session
 from sqlalchemy.orm import relationship
 from uuid import uuid4
@@ -71,7 +70,7 @@ class DataSource(Base, TimestampMixin):
         "DataSourceItem",
         cascade="all, delete-orphan",
         lazy="dynamic",
-        backref=backref("source"),
+        back_populates="source",
     )
 
     @property
@@ -135,8 +134,8 @@ class DataSourceItem(Base, TimestampMixin):
     )
 
     election: 'relationship[Election | None]' = relationship(
-        "Election",
-        backref="data_sources"
+        'Election',
+        back_populates="data_sources"
     )
 
     #: the vote
@@ -147,12 +146,14 @@ class DataSourceItem(Base, TimestampMixin):
     )
 
     vote: 'relationship[Vote | None]' = relationship(
-        "Vote",
-        backref="data_sources"
+        'Vote',
+        back_populates="data_sources"
     )
 
-    if TYPE_CHECKING:
-        source: relationship[DataSource]
+    source: 'relationship[DataSource]' = relationship(
+        DataSource,
+        back_populates='items'
+    )
 
     @property
     def item(self) -> Election | Vote | None:

src/onegov/election_day/models/election/election.py

@@ -14,8 +14,8 @@
 from onegov.election_day.models.mixins import StatusMixin
 from onegov.election_day.models.mixins import summarized_property
 from onegov.election_day.models.mixins import TitleTranslationsMixin
-from onegov.election_day.models.party_result.mixins import \
-    PartyResultsOptionsMixin
+from onegov.election_day.models.party_result.mixins import (
+    PartyResultsOptionsMixin)
 from sqlalchemy import Column
 from sqlalchemy import Date
 from sqlalchemy import ForeignKey
@@ -33,8 +33,11 @@
     import datetime
     from collections.abc import Mapping
     from onegov.core.types import AppenderQuery
+    from onegov.election_day.models import DataSourceItem
     from onegov.election_day.models import ElectionCompound
     from onegov.election_day.models import ElectionRelationship
+    from onegov.election_day.models import Notification
+    from onegov.election_day.models import Screen
     from sqlalchemy.orm import Query
     from sqlalchemy.sql import ColumnElement
     from typing import NamedTuple
@@ -381,3 +384,23 @@ def clear_results(self, clear_all: bool = False) -> None:
         ).delete()
         session.flush()
         session.expire_all()
+
+    #: data source items linked to this election
+    data_sources: 'relationship[list[DataSourceItem]]' = relationship(
+        'DataSourceItem',
+        back_populates='election'
+    )
+
+    #: notifcations linked to this election
+    notifications: 'relationship[AppenderQuery[Notification]]'
+    notifications = relationship(  # type:ignore[misc]
+        'onegov.election_day.models.notification.Notification',
+        back_populates='election',
+        lazy='dynamic'
+    )
+
+    #: screens linked to this election
+    screens: 'relationship[AppenderQuery[Screen]]' = relationship(
+        'Screen',
+        back_populates='election',
+    )

src/onegov/election_day/models/election_compound/election_compound.py

@@ -5,19 +5,19 @@
 from onegov.core.orm.mixins import meta_property
 from onegov.core.orm.types import HSTORE
 from onegov.core.utils import groupbylist
-from onegov.election_day.models.election_compound.mixins import \
-    DerivedAttributesMixin
+from onegov.election_day.models.election_compound.mixins import (
+    DerivedAttributesMixin)
 from onegov.election_day.models.mixins import DomainOfInfluenceMixin
 from onegov.election_day.models.mixins import ExplanationsPdfMixin
 from onegov.election_day.models.mixins import IdFromTitlesMixin
 from onegov.election_day.models.mixins import LastModifiedMixin
 from onegov.election_day.models.mixins import TitleTranslationsMixin
-from onegov.election_day.models.party_result.mixins import \
-    HistoricalPartyResultsMixin
-from onegov.election_day.models.party_result.mixins import \
-    PartyResultsCheckMixin
-from onegov.election_day.models.party_result.mixins import \
-    PartyResultsOptionsMixin
+from onegov.election_day.models.party_result.mixins import (
+    HistoricalPartyResultsMixin)
+from onegov.election_day.models.party_result.mixins import (
+    PartyResultsCheckMixin)
+from onegov.election_day.models.party_result.mixins import (
+    PartyResultsOptionsMixin)
 from onegov.file import NamedFile
 from sqlalchemy import Column, Boolean
 from sqlalchemy import Date
@@ -33,8 +33,10 @@
     from onegov.core.types import AppenderQuery
     from onegov.election_day.models import Election
     from onegov.election_day.models import ElectionCompoundRelationship
+    from onegov.election_day.models import Notification
     from onegov.election_day.models import PartyPanachageResult
     from onegov.election_day.models import PartyResult
+    from onegov.election_day.models import Screen
     from onegov.election_day.types import DomainOfInfluence
     import datetime
 
@@ -230,6 +232,20 @@ def elected_candidates(self) -> list[tuple[str, str]]:
 
         return result
 
+    #: notifcations linked to this election compound
+    notifications: 'relationship[AppenderQuery[Notification]]'
+    notifications = relationship(  # type:ignore[misc]
+        'onegov.election_day.models.notification.Notification',
+        back_populates='election_compound',
+        lazy='dynamic'
+    )
+
+    #: screens linked to this election compound
+    screens: 'relationship[AppenderQuery[Screen]]' = relationship(
+        'Screen',
+        back_populates='election_compound',
+    )
+
     #: may be used to store a link related to this election
     related_link: dict_property[str | None] = meta_property(
         'related_link'

src/onegov/election_day/models/notification.py

@@ -19,7 +19,6 @@
 from sqlalchemy import func
 from sqlalchemy import or_
 from sqlalchemy import Text
-from sqlalchemy.orm import backref
 from sqlalchemy.orm import relationship
 from uuid import uuid4
 
@@ -78,7 +77,7 @@ class Notification(Base, TimestampMixin):
     #: The corresponding election
     election: 'relationship[Election | None]' = relationship(
         'Election',
-        backref=backref('notifications', lazy='dynamic')
+        back_populates='notifications'
     )
 
     #: The corresponding election compound id
@@ -93,7 +92,7 @@ class Notification(Base, TimestampMixin):
     #: The corresponding election compound
     election_compound: 'relationship[ElectionCompound | None]' = relationship(
         'ElectionCompound',
-        backref=backref('notifications', lazy='dynamic')
+        back_populates='notifications'
     )
 
     #: The corresponding vote id
@@ -106,7 +105,7 @@ class Notification(Base, TimestampMixin):
     #: The corresponding vote
     vote: 'relationship[Vote | None]' = relationship(
         'Vote',
-        backref=backref('notifications', lazy='dynamic')
+        back_populates='notifications'
     )
 
     def update_from_model(

src/onegov/election_day/models/screen.py

@@ -67,7 +67,7 @@ class Screen(Base, ContentMixin, TimestampMixin):
     )
     vote: 'relationship[Vote | None]' = relationship(
         'Vote',
-        backref='screens'
+        back_populates='screens'
     )
 
     #: The election
@@ -77,7 +77,7 @@ class Screen(Base, ContentMixin, TimestampMixin):
     )
     election: 'relationship[Election | None]' = relationship(
         'Election',
-        backref='screens'
+        back_populates='screens'
     )
 
     #: The election compound
@@ -87,7 +87,7 @@ class Screen(Base, ContentMixin, TimestampMixin):
     )
     election_compound: 'relationship[ElectionCompound | None]' = relationship(
         'ElectionCompound',
-        backref='screens'
+        back_populates='screens'
     )
 
     #: The domain of the election compound part.

src/onegov/election_day/models/vote/vote.py

@@ -28,6 +28,10 @@
 if TYPE_CHECKING:
     import datetime
     from collections.abc import Mapping
+    from onegov.core.types import AppenderQuery
+    from onegov.election_day.models import DataSourceItem
+    from onegov.election_day.models import Notification
+    from onegov.election_day.models import Screen
     from onegov.election_day.types import BallotType
     from sqlalchemy.sql import ColumnElement
 
@@ -305,6 +309,26 @@ def last_modified(cls) -> 'ColumnElement[datetime.datetime | None]':
             cls.last_change, cls.last_result_change, cls.last_ballot_change
         )
 
+    #: data source items linked to this vote
+    data_sources: 'relationship[list[DataSourceItem]]' = relationship(
+        'DataSourceItem',
+        back_populates='vote'
+    )
+
+    #: notifcations linked to this vote
+    notifications: 'relationship[AppenderQuery[Notification]]'
+    notifications = relationship(  # type:ignore[misc]
+        'onegov.election_day.models.notification.Notification',
+        back_populates='vote',
+        lazy='dynamic'
+    )
+
+    #: screens linked to this vote
+    screens: 'relationship[AppenderQuery[Screen]]' = relationship(
+        'Screen',
+        back_populates='vote',
+    )
+
     #: may be used to store a link related to this vote
     related_link: dict_property[str | None] = meta_property('related_link')
 

src/onegov/election_day/views/upload/election.py

@@ -80,7 +80,7 @@ def view_upload_majorz_election(
                 )
             elif form.file_format.data == 'wabsti_c':
                 source: DataSourceItem
-                for source in self.data_sources:  # type:ignore[attr-defined]
+                for source in self.data_sources:
                     assert source.district is not None
                     assert source.number is not None
                     assert form.wm_wahl.data is not None
@@ -182,7 +182,7 @@ def view_upload_proporz_election(
                 )
             elif form.file_format.data == 'wabsti_c':
                 source: DataSourceItem
-                for source in self.data_sources:  # type:ignore[attr-defined]
+                for source in self.data_sources:
                     assert source.number is not None
                     assert form.wp_wahl.data is not None
                     assert form.wp_wahl.file is not None

src/onegov/election_day/views/upload/vote.py

@@ -62,7 +62,7 @@ def view_upload(
                 assert form.sg_gemeinden.data is not None
                 assert form.sg_gemeinden.file is not None
                 source: DataSourceItem
-                for source in self.data_sources:  # type:ignore[attr-defined]
+                for source in self.data_sources:
                     assert source.number is not None
                     assert source.district is not None
                     errors.extend(

src/onegov/file/models/file.py

@@ -16,6 +16,7 @@
 from onegov.file.attachments import ProcessedUploadedFile
 from onegov.file.filters import OnlyIfImage, WithThumbnailFilter
 from onegov.file.filters import OnlyIfPDF, WithPDFThumbnailFilter
+from onegov.file.models.fileset import file_to_set_associations
 from onegov.file.utils import extension_for_content_type
 from onegov.search import ORMSearchable
 from pathlib import Path
@@ -25,7 +26,7 @@
 from sqlalchemy import text
 from sqlalchemy import type_coerce
 from sqlalchemy.ext.hybrid import hybrid_property
-from sqlalchemy.orm import deferred
+from sqlalchemy.orm import deferred, relationship
 from sqlalchemy.orm import object_session, Session
 from sqlalchemy.orm.attributes import flag_modified
 from time import monotonic
@@ -41,7 +42,6 @@
     from onegov.file import FileSet
     from onegov.file.types import FileStats, SignatureMetadata
     from sqlalchemy.engine import Dialect
-    from sqlalchemy.orm import relationship
     from sqlalchemy.orm.session import SessionTransaction
     from sqlalchemy.sql.type_api import TypeEngine
 
@@ -252,9 +252,11 @@ class File(Base, Associable, TimestampMixin):
     #: store additional information using e.g. `meta_property`
     meta: 'Column[dict[str, Any]]' = Column(JSON, nullable=False, default=dict)
 
-    if TYPE_CHECKING:
-        # forward declare backref
-        filesets: 'relationship[list[FileSet]]'
+    filesets: 'relationship[list[FileSet]]' = relationship(
+        'FileSet',
+        secondary=file_to_set_associations,
+        back_populates='files'
+    )
 
     __mapper_args__ = {
         'polymorphic_on': 'type',

src/onegov/file/models/fileset.py

@@ -59,7 +59,7 @@ class FileSet(Base, ContentMixin, TimestampMixin):
     files: 'relationship[list[File]]' = relationship(
         'File',
         secondary=file_to_set_associations,
-        backref='filesets',
+        back_populates='filesets',
         order_by='desc(File.last_change)'
     )
 

src/onegov/form/models/definition.py

@@ -77,14 +77,14 @@ def id(self) -> str:
     #: link between forms and submissions
     submissions: 'relationship[list[FormSubmission]]' = relationship(
         FormSubmission,
-        backref='form'
+        back_populates='form'
     )
 
     #: link between forms and registration windows
     registration_windows: 'relationship[list[FormRegistrationWindow]]'
     registration_windows = relationship(
         FormRegistrationWindow,
-        backref='form',
+        back_populates='form',
         order_by='FormRegistrationWindow.start',
         cascade='all, delete-orphan'
     )
@@ -257,14 +257,14 @@ def id(self) -> str:
     #: link between surveys and submissions
     submissions: 'relationship[list[SurveySubmission]]' = relationship(
         SurveySubmission,
-        backref='survey'
+        back_populates='survey'
     )
 
     #: link between surveys and submission windows
     submission_windows: 'relationship[list[SurveySubmissionWindow]]'
     submission_windows = relationship(
         SurveySubmissionWindow,
-        backref='survey',
+        back_populates='survey',
         order_by='SurveySubmissionWindow.start',
         cascade='all, delete-orphan'
     )

src/onegov/form/models/registration_window.py

@@ -58,6 +58,12 @@ class FormRegistrationWindow(Base, TimestampMixin):
         nullable=False
     )
 
+    #: the form to which this registration window belongs
+    form: 'relationship[FormDefinition]' = relationship(
+        'FormDefinition',
+        back_populates='registration_windows'
+    )
+
     #: true if the registration window is enabled
     enabled: 'Column[bool]' = Column(Boolean, nullable=False, default=True)
 
@@ -80,16 +86,12 @@ class FormRegistrationWindow(Base, TimestampMixin):
     #: enable an overflow of submissions
     overflow: 'Column[bool]' = Column(Boolean, nullable=False, default=True)
 
-    #: submissions linked to this
+    #: submissions linked to this registration window
     submissions: 'relationship[list[FormSubmission]]' = relationship(
         FormSubmission,
-        backref='registration_window'
+        back_populates='registration_window'
     )
 
-    if TYPE_CHECKING:
-        # forward declare backref
-        form: relationship[FormDefinition]
-
     __table_args__ = (
 
         # ensures that there are no overlapping date ranges within one form