Add the AppState model

This allows setting application state during run time

calsocial/models.py

@@ -21,12 +21,14 @@ from datetime import datetime
 from enum import Enum
 from warnings import warn
 
+from flask import current_app
 from flask_babelex import lazy_gettext
 from flask_security import UserMixin, RoleMixin
 from flask_sqlalchemy import SQLAlchemy
 from sqlalchemy.orm.exc import NoResultFound
 from sqlalchemy_utils.types.choice import ChoiceType
 
+from .app_state import app_state_base
 from .cache import cache
 from .utils import force_locale
 
@@ -206,7 +208,6 @@ class User(db.Model, UserMixin):
         If the user didn’t set a time zone yet, the application default is used.
         """
 
-        from flask import current_app
         from pytz import timezone
         from pytz.exceptions import UnknownTimeZoneError
 
@@ -789,3 +790,64 @@ class Response(db.Model):  # pylint: disable=too-few-public-methods
 
     #: The response itself
     response = db.Column(db.Enum(ResponseType), nullable=False)
+
+
+class AppState(app_state_base(db.Model)):  # pylint: disable=too-few-public-methods
+    """Database model for application state values
+    """
+
+    __tablename__ = 'app_state'
+
+    #: The environment that set this key
+    env = db.Column(db.String(length=40), nullable=False, primary_key=True)
+
+    #: The key
+    key = db.Column(db.String(length=80), nullable=False, primary_key=True)
+
+    #: The value of the key
+    value = db.Column(db.Unicode(length=200), nullable=True)
+
+    @classmethod
+    def __get_state__(cls, key):
+        try:
+            record = cls.query \
+                        .filter(cls.env == current_app.env) \
+                        .filter(cls.key == key) \
+                        .one()
+        except NoResultFound:
+            return None
+
+        return record.value
+
+    @classmethod
+    def __set_state__(cls, key, value):
+        try:
+            record = cls.query \
+                        .filter(cls.env == current_app.env) \
+                        .filter(cls.key == key) \
+                        .one()
+        except NoResultFound:
+            record = cls(env=current_app.env, key=key)
+
+        record.value = value
+        db.session.add(record)
+        db.session.commit()
+
+    @classmethod
+    def __set_state_default__(cls, key, value):
+        try:
+            record = cls.query \
+                        .filter(cls.env == current_app.env) \
+                        .filter(cls.key == key) \
+                        .one()
+        except NoResultFound:
+            pass
+        else:
+            return
+
+        record = cls(env=current_app.env, key=key, value=value)
+        db.session.add(record)
+        db.session.commit()
+
+    def __repr__(self):
+        return f'<AppState {self.env}:{self.key}="{self.value}"'