Merge pull request #64 from DanCardin/dc/view_function

feat: Allow __view__ to be a callable.

pyproject.toml

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "sqlalchemy-declarative-extensions"
-version = "0.9.0"
+version = "0.9.1"
 authors = ["Dan Cardin <ddcardin@gmail.com>"]
 
 description = "Library to declare additional kinds of objects not natively supported by SQLAlchemy/Alembic."

src/sqlalchemy_declarative_extensions/view/base.py

@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+import inspect
 import uuid
 import warnings
 from dataclasses import dataclass, field, replace
@@ -41,8 +42,10 @@ def view(
     Given some object with the attributes: `__tablename__`, (optionally for schema) `__table_args__`,
     and `__view__`, registers a View object.
 
-    The `__view__` attribute can be either a raw string query, or a SQLAlchemy object
-    capable of being compiled (namely :func:`~sqlalchemy.sql.expression.text` or :func:`~sqlalchemy.sql.expression.select`).
+    The `__view__` attribute can be either a raw string query, a SQLAlchemy object
+    capable of being compiled (namely :func:`~sqlalchemy.sql.expression.text` or
+    :func:`~sqlalchemy.sql.expression.select`), or a no-argument function which returns
+    either of the two.
 
     This intentionally allows one to register a Model definition as a view,
     and have it register in the same way you might otherwise manually define it.
@@ -128,6 +131,9 @@ def table_args(self):
 
     @property
     def view_def(self):
+        if inspect.isfunction(self.cls.__view__):
+            return self.cls.__view__()
+
         return self.cls.__view__
 
     @property

tests/view/test_view_function.py

@@ -0,0 +1,48 @@
+from pytest_mock_resources import create_postgres_fixture
+from sqlalchemy import Column, text, types
+
+from sqlalchemy_declarative_extensions import (
+    declarative_database,
+    register_sqlalchemy_events,
+    view,
+)
+from sqlalchemy_declarative_extensions.sqlalchemy import declarative_base, select
+
+_Base = declarative_base()
+
+
+@declarative_database
+class Base(_Base):  # type: ignore
+    __abstract__ = True
+
+
+class Foo(Base):
+    __tablename__ = "foo"
+    id = Column(types.Integer(), primary_key=True)
+
+
+@view(Base)
+class HighFoo:
+    __tablename__ = "high_foo"
+
+    @staticmethod
+    def __view__():
+        return select(Foo.__table__).where(Foo.__table__.c.id >= 10)
+
+
+register_sqlalchemy_events(Base.metadata, schemas=True, views=True, rows=True)
+
+pg = create_postgres_fixture(
+    scope="function", engine_kwargs={"echo": True}, session=True
+)
+
+
+def test_created_together(pg):
+    Base.metadata.create_all(pg.connection())
+
+    for i in range(8, 12):
+        pg.add(Foo(id=i))
+    pg.commit()
+
+    result = [i for (i,) in pg.execute(text('select id from "high_foo"'))]
+    assert result == [10, 11]