streamlined declarative mapping code, (re)added assoc. proxies, fixed bugs caused by the switch to declarative

the_works/models.py

@@ -1,27 +1,28 @@
-# code is based on output from `sqlacodegen --generator declarative sqlite:///path/to/the_works.sqlite` 
+# code is built upon output from sqlacodegen 
 
-from typing import List, Optional
-
-from sqlalchemy import Column, ForeignKey, Table, types
-from sqlalchemy.orm import DeclarativeBase, Mapped, mapped_column, relationship
-
-from flask import url_for
 import sys
+from typing import List, Optional
+from sqlalchemy import ForeignKey, types
+from sqlalchemy.orm import DeclarativeBase, Mapped, mapped_column, relationship
+from sqlalchemy.ext.associationproxy import AssociationProxy, association_proxy
+from flask import url_for
 
 
 class Base(DeclarativeBase):
-  def _asdict(self):
+  def asdict(self) -> dict:
     d = {}
     for col in self.__table__.c:
-      if type(col.type) == types.BLOB:
+      if isinstance(col.type, types.BLOB):
-        d[col.key] = "Blob (NULL)" if self.__getattribute__(col.key) == None else f"Blob ({sys.getsizeof(self.__getattribute__(col.key))} Bytes)"
+        d[col.key] = "Blob (NULL)" if self.__getattribute__(col.key) is None else f"Blob ({sys.getsizeof(self.__getattribute__(col.key))} Bytes)"
       else:
-        value = str(self.__getattribute__(col.key))
+        if isinstance(value := self.__getattribute__(col.key), str) and len(value) > 50:
-        d[col.key] = value[:50] + '...' if len(value) > 50 else value
+          d[col.key] = value[:48] + '...'
+        else:
+          d[col.key] = value
     return d
 
-  def __repr__(self):
+  def __repr__(self) -> str:
-    return f"{type(self).__name__}({str(self._asdict())})"    
+    return f"{type(self).__name__}({str(self.asdict())})"    
 
 
 class Genre(Base):
@@ -30,8 +31,8 @@ class Genre(Base):
   ID: Mapped[int] = mapped_column(primary_key=True)
   Genre: Mapped[str]
 
-  text: Mapped[List['Text']] = relationship('Text', secondary='Text_Genre', back_populates='genre')
+  texte: Mapped[List['Text_Genre']] = relationship(back_populates='genre')
-  werk: Mapped[List['Werk']] = relationship('Werk', secondary='Werk_Genre', back_populates='genre')
+  werke: Mapped[List['Werk_Genre']] = relationship(back_populates='genre')
 
 
 class Herausgeber(Base):
@@ -40,7 +41,7 @@ class Herausgeber(Base):
   ID: Mapped[int] = mapped_column(primary_key=True)
   Name: Mapped[str]
 
-  werk: Mapped[List['Werk']] = relationship('Werk', secondary='Werk_Herausgeber', back_populates='herausgeber')
+  werke: Mapped[List['Werk_Herausgeber']] = relationship(back_populates='herausgeber')
 
 
 class Pseudonym(Base):
@@ -49,7 +50,7 @@ class Pseudonym(Base):
   ID: Mapped[int] = mapped_column(primary_key=True)
   Pseudonym: Mapped[str]
 
-  veroeffentlichung: Mapped[List['Veroeffentlichung']] = relationship('Veroeffentlichung', back_populates='pseudonym')
+  veroeffentlichung: Mapped[List['Veroeffentlichung']] = relationship(back_populates='pseudonym')
 
 
 class Sprache(Base):
@@ -58,7 +59,7 @@ class Sprache(Base):
   ID: Mapped[int] = mapped_column(primary_key=True)
   Sprache: Mapped[str]
 
-  text: Mapped[List['Text']] = relationship('Text', back_populates='sprache')
+  text: Mapped[List['Text']] = relationship(back_populates='sprache')
 
 
 class Textform(Base):
@@ -67,7 +68,7 @@ class Textform(Base):
   ID: Mapped[int] = mapped_column(primary_key=True)
   Textform: Mapped[str]
 
-  text: Mapped[List['Text']] = relationship('Text', back_populates='textform')
+  text: Mapped[List['Text']] = relationship(back_populates='textform')
 
 
 class Titelbild(Base):
@@ -83,10 +84,10 @@ class Titelbild(Base):
   Thumbnail: Mapped[bytes]
   sha256: Mapped[str] = mapped_column(unique=True)
 
-  werk: Mapped[List['Werk']] = relationship('Werk', back_populates='titelbild')
+  werk: Mapped[List['Werk']] = relationship(back_populates='titelbild')
 
-  def _asdict_with_urls(self):
+  def asdict_with_urls(self):
-    tb = self._asdict()
+    tb = self.asdict()
     tb["Bild"] = url_for("titelbild.image", id=self.ID)
     tb["Thumbnail"] = url_for("titelbild.thumbnail", id=self.ID)
     return tb
@@ -98,8 +99,8 @@ class Verlag(Base):
   ID: Mapped[int] = mapped_column(primary_key=True)
   Verlag: Mapped[str]
 
-  reihe: Mapped[List['Reihe']] = relationship('Reihe', back_populates='verlag')
+  reihe: Mapped[List['Reihe']] = relationship(back_populates='verlag')
-  werk: Mapped[List['Werk']] = relationship('Werk', back_populates='verlag')
+  werk: Mapped[List['Werk']] = relationship(back_populates='verlag')
 
 
 class Werksform(Base):
@@ -108,7 +109,7 @@ class Werksform(Base):
   ID: Mapped[int] = mapped_column(primary_key=True)
   Werksform: Mapped[str]
 
-  werk: Mapped[List['Werk']] = relationship('Werk', back_populates='werksform')
+  werk: Mapped[List['Werk']] = relationship(back_populates='werksform')
 
 
 class Reihe(Base):
@@ -116,92 +117,117 @@ class Reihe(Base):
 
   ID: Mapped[int] = mapped_column(primary_key=True)
   Titel: Mapped[str]
-  Verlag: Mapped[Optional[str]] = mapped_column('Verlag', ForeignKey('Verlag.ID'))
 
-  verlag: Mapped[Optional['Verlag']] = relationship('Verlag', back_populates='reihe')
+  Verlag: Mapped[Optional[str]] = mapped_column(ForeignKey('Verlag.ID'))
-  text: Mapped[List['Text']] = relationship('Text', back_populates='reihe')
+  verlag: Mapped['Verlag'] = relationship(back_populates='reihe')
-  werk: Mapped[List['Werk']] = relationship('Werk', back_populates='reihe')
+
+  text: Mapped[List['Text']] = relationship(back_populates='reihe')
+  werk: Mapped[List['Werk']] = relationship(back_populates='reihe')
 
 
 class Text(Base):
   __tablename__ = 'Text'
 
+  # regular columns
   ID: Mapped[int] = mapped_column(primary_key=True)
   Titel: Mapped[str]
   Untertitel: Mapped[Optional[str]]
-  Reihe: Mapped[Optional[int]] = mapped_column('Reihe', ForeignKey('Reihe.ID'))
-  Textform: Mapped[Optional[int]] = mapped_column('Textform', ForeignKey('Textform.ID'))
-  Sprache: Mapped[Optional[int]] = mapped_column('Sprache', ForeignKey('Sprache.ID'))
 
-  genre: Mapped[List['Genre']] = relationship('Genre', secondary='Text_Genre', back_populates='text')
+  # many-to-one
-  reihe: Mapped[Optional['Reihe']] = relationship('Reihe', back_populates='text')
+  Reihe: Mapped[Optional[int]] = mapped_column(ForeignKey('Reihe.ID'))
-  sprache: Mapped[Optional['Sprache']] = relationship('Sprache', back_populates='text')
+  reihe: Mapped[Optional["Reihe"]] = relationship(back_populates="text")
-  textform: Mapped[Optional['Textform']] = relationship('Textform', back_populates='text')
+  Sprache: Mapped[int] = mapped_column(ForeignKey('Sprache.ID'))
-  veroeffentlichung: Mapped[List['Veroeffentlichung']] = relationship('Veroeffentlichung', back_populates='text')
+  sprache: Mapped['Sprache'] = relationship(back_populates='text')
+  Textform: Mapped[int] = mapped_column(ForeignKey('Textform.ID'))
+  textform: Mapped['Textform'] = relationship(back_populates='text')
+
+  # one-to-many
+  veroeffentlichung: Mapped[List['Veroeffentlichung']] = relationship(back_populates='text')
+
+  # many-to-many
+  genres: Mapped[List['Text_Genre']] = relationship(back_populates='text', cascade="all, delete-orphan")
+  genre_ids: AssociationProxy[List["Genre"]] = association_proxy("genres", "Genre", creator=lambda genre_id: Text_Genre(Genre=genre_id))
 
 
 class Werk(Base):
   __tablename__ = 'Werk'
 
+  # regular columns
   ID: Mapped[int] = mapped_column(primary_key=True)
   Titel: Mapped[str]
   Untertitel: Mapped[Optional[str]]
-  Werksform: Mapped[Optional[int]] = mapped_column('Werksform', ForeignKey('Werksform.ID'))
-  Verlag: Mapped[Optional[int]] = mapped_column('Verlag', ForeignKey('Verlag.ID'))
-  Reihe: Mapped[Optional[int]] = mapped_column('Reihe', ForeignKey('Reihe.ID'))
   Reihennummer: Mapped[Optional[str]]
   Erscheinungsdatum: Mapped[Optional[str]]
   ISBN_13: Mapped[Optional[str]]
   ISBN_10: Mapped[Optional[str]]
   ISSN: Mapped[Optional[str]]
   Preis: Mapped[Optional[str]]
-  Titelbild: Mapped[Optional[int]] = mapped_column('Titelbild', ForeignKey('Titelbild.ID'))
   Klappentext: Mapped[Optional[str]]
   Anmerkungen: Mapped[Optional[str]]
 
-  genre: Mapped[List['Genre']] = relationship('Genre', secondary='Werk_Genre', back_populates='werk')
+  # many-to-one
-  herausgeber: Mapped[List['Herausgeber']] = relationship('Herausgeber', secondary='Werk_Herausgeber', back_populates='werk')
+  Reihe: Mapped[Optional[int]] = mapped_column(ForeignKey('Reihe.ID'))
-  reihe: Mapped[Optional['Reihe']] = relationship('Reihe', back_populates='werk')
+  reihe: Mapped[Optional['Reihe']] = relationship(back_populates='werk')
-  titelbild: Mapped[Optional['Titelbild']] = relationship('Titelbild', back_populates='werk')
+  Titelbild: Mapped[Optional[int]] = mapped_column(ForeignKey('Titelbild.ID'))
-  verlag: Mapped[Optional['Verlag']] = relationship('Verlag', back_populates='werk')
+  titelbild: Mapped[Optional['Titelbild']] = relationship(back_populates='werk')
-  werksform: Mapped[Optional['Werksform']] = relationship('Werksform', back_populates='werk')
+  Verlag: Mapped[Optional[int]] = mapped_column(ForeignKey('Verlag.ID'))
-  veroeffentlichung: Mapped[List['Veroeffentlichung']] = relationship('Veroeffentlichung', back_populates='werk')
+  verlag: Mapped[Optional['Verlag']] = relationship(back_populates='werk')
+  Werksform: Mapped[int] = mapped_column(ForeignKey('Werksform.ID'))
+  werksform: Mapped['Werksform'] = relationship(back_populates='werk')
+
+  # one-to-many
+  veroeffentlichung: Mapped[List['Veroeffentlichung']] = relationship(back_populates='werk')
+
+  # many-to-many
+  genres: Mapped[List['Werk_Genre']] = relationship(back_populates='werk', cascade='all, delete-orphan')
+  genre_ids: AssociationProxy[List["Genre"]] = association_proxy("genres", "Genre", creator=lambda genre_id: Werk_Genre(Genre=genre_id))
+  herausgeber: Mapped[List['Werk_Herausgeber']] = relationship(back_populates='werk', cascade="all, delete-orphan")
+  herausgeber_ids: AssociationProxy[List['Herausgeber']] = association_proxy("herausgeber", "Herausgeber", creator=lambda hrsg_id: Werk_Herausgeber(Herausgeber=hrsg_id))
 
 
 class Veroeffentlichung(Base):
   __tablename__ = 'Veroeffentlichung'
 
+  # regular columns
   ID: Mapped[int] = mapped_column(primary_key=True)
-  Text: Mapped[int] = mapped_column('Text', ForeignKey('Text.ID'))
-  Werk: Mapped[int] = mapped_column('Werk', ForeignKey('Werk.ID'))
-  Pseudonym: Mapped[int] = mapped_column('Pseudonym', ForeignKey('Pseudonym.ID'))
   AltTitel: Mapped[Optional[str]]
   AltUntertitel: Mapped[Optional[str]]
 
-  pseudonym: Mapped['Pseudonym'] = relationship('Pseudonym', back_populates='veroeffentlichung')
+  # many-to-one
-  text: Mapped['Text'] = relationship('Text', back_populates='veroeffentlichung')
+  Pseudonym: Mapped[int] = mapped_column(ForeignKey('Pseudonym.ID'))
-  werk: Mapped['Werk'] = relationship('Werk', back_populates='veroeffentlichung')
+  pseudonym: Mapped['Pseudonym'] = relationship(back_populates='veroeffentlichung')
+  Text: Mapped[int] = mapped_column(ForeignKey('Text.ID'))
+  text: Mapped['Text'] = relationship(back_populates='veroeffentlichung')
+  Werk: Mapped[int] = mapped_column(ForeignKey('Werk.ID'))
+  werk: Mapped['Werk'] = relationship(back_populates='veroeffentlichung')
 
 
-t_Text_Genre = Table(
+class Text_Genre(Base):
-  'Text_Genre', 
+  __tablename__ = 'Text_Genre'
-  Base.metadata,
+
-  Column('Text', ForeignKey('Text.ID'), primary_key=True),
+  Text: Mapped[int] = mapped_column(ForeignKey("Text.ID"), primary_key=True)
-  Column('Genre', ForeignKey('Genre.ID'), primary_key=True)
+  Genre: Mapped[int] = mapped_column(ForeignKey("Genre.ID"), primary_key=True)
-)
+
+  text: Mapped['Text'] = relationship(back_populates="genres")
+  genre: Mapped['Genre'] = relationship(back_populates="texte")
 
 
-t_Werk_Genre = Table(
+class Werk_Genre(Base):
-  'Werk_Genre', 
+  __tablename__ = 'Werk_Genre'
-  Base.metadata,
+
-  Column('Werk', ForeignKey('Werk.ID'), primary_key=True),
+  Werk: Mapped[int] = mapped_column(ForeignKey('Werk.ID'), primary_key=True)
-  Column('Genre', ForeignKey('Genre.ID'), primary_key=True)
+  Genre: Mapped[int] = mapped_column(ForeignKey("Genre.ID"), primary_key=True)
-)
+
+  werk: Mapped['Werk'] = relationship(back_populates="genres")
+  genre: Mapped['Genre'] = relationship(back_populates="werke")
 
 
-t_Werk_Herausgeber = Table(
+class Werk_Herausgeber(Base):
-  'Werk_Herausgeber', 
+  __tablename__ = 'Werk_Herausgeber'
-  Base.metadata,
+
-  Column('Herausgeber', ForeignKey('Herausgeber.ID'), primary_key=True),
+  Werk: Mapped[int] = mapped_column(ForeignKey('Werk.ID'), primary_key=True)
-  Column('Werk', ForeignKey('Werk.ID'), primary_key=True)
+  Herausgeber: Mapped[int] = mapped_column(ForeignKey("Herausgeber.ID"), primary_key=True)
-)
+
+  werk: Mapped['Werk'] = relationship(back_populates="herausgeber")
+  herausgeber: Mapped['Herausgeber'] = relationship(back_populates="werke")
+

the_works/views/text.py

@@ -1,7 +1,7 @@
 from flask import Blueprint, render_template, request, redirect, flash, url_for
-from sqlalchemy import select, insert, update, delete
+from sqlalchemy import select
 from the_works.database import db
-from the_works.models import Text, Reihe, Sprache, Textform, t_Text_Genre, Genre
+from the_works.models import Text, Reihe, Sprache, Textform, Genre
 
 bp = Blueprint("text", __name__)
 
@@ -23,8 +23,7 @@ def all():
       "tf_id": row.Text.Textform,
       "Sprache": row.Sprache.Sprache, 
       "s_id": row.Text.Sprache,
-      "Genre_list": [tg.genre.Genre for tg in row.Text.text_genre],
+      "Genre_list": [tg.genre.Genre for tg in row.Text.genres]
-      "g_id_list": row.Text.genres
     })
   return render_template("views/text.html", texte=texte)
 
@@ -35,15 +34,11 @@ def read(id):
     return render_template("views/text_detail.html", text={"ID": 0}, reihen=db.session.scalars(select(Reihe)), textformen=db.session.scalars(select(Textform)), sprachen=db.session.scalars(select(Sprache)), genres=db.session.scalars(select(Genre)))
   # all other ids -> update existing entry 
   t = db.session.get(Text, id)
-  text = {
+  if not t:
-    "ID": t.ID,
+    raise ValueError(f"Text with ID {id} not found")
-    "Titel": t.Titel,
+  text = t.asdict()
-    "Untertitel": t.Untertitel or "",
+  text["Genres"] = t.genre_ids
-    "Reihe": t.Reihe or "",
+
-    "Textform": t.Textform,
-    "Sprache": t.Sprache,
-    "Genres": t.genres
-  }
   return render_template("views/text_detail.html", text=text, reihen=db.session.scalars(select(Reihe)), textformen=db.session.scalars(select(Textform)), sprachen=db.session.scalars(select(Sprache)), genres=db.session.scalars(select(Genre)))
 
 @bp.route("/text/create", methods=["POST"])
@@ -56,7 +51,7 @@ def create():
     Sprache = request.form["form_Sprache"]
   )
   for g in request.form.getlist("form_Genres"):
-    text.genres.append(g)
+    text.genre_ids.append(int(g))
   db.session.add(text)
   db.session.commit()
   flash("Eintrag erfolgreich hinzugefügt")
@@ -75,11 +70,11 @@ def update(id):
   text.Sprache = request.form["form_Sprache"]
 
   # update genre list by removing genres not in form selection and adding selected ones not currently in list 
-  form_set = set(map(lambda g: int(g), request.form.getlist("form_Genre")))
+  form_set = set(map(int, request.form.getlist("form_Genre")))
-  for g in set(text.genres) - form_set:
+  for g in set(text.genre_ids) - form_set:
-    text.genres.remove(g)
+    text.genre_ids.remove(g)
-  for g in form_set - set(text.genres):
+  for g in form_set - set(text.genre_ids):
-    text.genres.append(g)
+    text.genre_ids.append(g)
 
   # commit changes
   db.session.commit()

the_works/views/werk.py

@@ -1,8 +1,7 @@
 from flask import Blueprint, render_template, request, redirect, flash, url_for
-from sqlalchemy import select, insert, update, delete
+from sqlalchemy import select
 from the_works.database import db
-from the_works.models import Werk, Reihe, Verlag, Werksform, t_Werk_Genre, Genre, t_Werk_Herausgeber, Herausgeber, Titelbild
+from the_works.models import Werk, Reihe, Verlag, Werksform, Genre, Herausgeber, Titelbild
-from the_works.views import titelbild as tb
 
 bp = Blueprint("werk", __name__)
 
@@ -29,11 +28,11 @@ def all():
       "ISSN": row.Werk.ISSN or "",
       "Preis": row.Werk.Preis or "",
 #      "Titelbild": url_for("titelbild.thumbnail", id=row.Werk.Titelbild) if row.Werk.Titelbild else "",
-      "Titelbild": db.session.get(Titelbild, row.Werk.Titelbild)._asdict_with_urls() if row.Werk.Titelbild else "",
+      "Titelbild": db.session.get(Titelbild, row.Werk.Titelbild).asdict_with_urls() if row.Werk.Titelbild else "",
       "Klappentext": row.Werk.Klappentext or "",
       "Anmerkungen": row.Werk.Anmerkungen or "",
-      "Herausgeber_list": [wh.herausgeber.Name for wh in row.Werk.werk_herausgeber],
+      "Herausgeber_list": [wh.herausgeber.Name for wh in row.Werk.herausgeber],
-      "Genre_list": [wg.genre.Genre for wg in row.Werk.werk_genre],
+      "Genre_list": [wg.genre.Genre for wg in row.Werk.genres],
     })
   return render_template("views/werk.html", werke=werke)
 
@@ -41,17 +40,19 @@ def all():
 @bp.route("/werk/read/<int:id>")
 def read(id):
   # prepare Titelbilder as dict including URLs for thumbnail and full pic
-  titelbilder = map(lambda t: t._asdict_with_urls(), db.session.scalars(select(Titelbild)))
+  titelbilder = map(lambda t: t.asdict_with_urls(), db.session.scalars(select(Titelbild)))
 
   # id of zero -> return empty data
   if id == 0:
     return render_template("views/werk_detail.html", werk={"ID": 0, "Erscheinungsdatum": ""}, reihen=db.session.scalars(select(Reihe)), verlage=db.session.scalars(select(Verlag)), werksformen=db.session.scalars(select(Werksform)), genres=db.session.scalars(select(Genre)), hrsg=db.session.scalars(select(Herausgeber)), titelbilder=titelbilder)
 
   # all other ids -> read existing entry from DB and return as dict
-  werk = db.session.get(Werk, id)
+  w = db.session.get(Werk, id)
-  if not werk:
+  if not w:
     raise ValueError(f"Werk with ID {id} not found")
-  werk = werk._asdict()
+  werk = w.asdict()
+  werk["Genres"] = w.genre_ids
+  werk["Herausgeber"] = w.herausgeber_ids
 
   return render_template("views/werk_detail.html", werk=werk, reihen=db.session.scalars(select(Reihe)), verlage=db.session.scalars(select(Verlag)), werksformen=db.session.scalars(select(Werksform)), genres=db.session.scalars(select(Genre)), hrsg=db.session.scalars(select(Herausgeber)), titelbilder=titelbilder)
 
@@ -75,9 +76,9 @@ def create():
     Anmerkungen = request.form["form_Anmerkungen"] or None
   )
   for g in request.form.getlist("form_Genre"):
-    werk.genres.append(g)
+    werk.genre_ids.append(g)
   for h in request.form.getlist("form_Herausgeber"):
-    werk.herausgeber.append(h)
+    werk.herausgeber_ids.append(h)
   db.session.add(werk)
   db.session.commit()
   flash("Eintrag erfolgreich hinzugefügt")
@@ -106,18 +107,18 @@ def update(id):
   werk.Anmerkungen = request.form["form_Anmerkungen"] or None
 
   # update associated values: Genre
-  form_set = set(map(lambda g: int(g), request.form.getlist("form_Genre")))
+  form_set = set(map(int, request.form.getlist("form_Genre")))
-  for g in set(werk.genres) - form_set:
+  for g in set(werk.genre_ids) - form_set:
-    werk.genres.remove(g)
+    werk.genre_ids.remove(g)
-  for g in form_set - set(werk.genres):
+  for g in form_set - set(werk.genre_ids):
-    werk.genres.append(g)
+    werk.genre_ids.append(g)
 
   # update associated values: Herausgeber
-  form_set = set(map(lambda h: int(h), request.form.getlist("form_Herausgeber")))
+  form_set = set(map(int, request.form.getlist("form_Herausgeber")))
-  for h in set(werk.herausgeber) - form_set:
+  for h in set(werk.herausgeber_ids) - form_set:
-    werk.herausgeber.remove(h)
+    werk.herausgeber_ids.remove(h)
-  for h in form_set - set(werk.herausgeber):
+  for h in form_set - set(werk.herausgeber_ids):
-    werk.herausgeber.append(h)
+    werk.herausgeber_ids.append(h)
 
   # commit changes
   db.session.commit()