remove history-meta for templates, replace with hand-made history table

history-meta's dynamic magic is insufficient for templates, where we
need to be able to refer to the specific history table to take
advantage of sqlalchemy's relationship management (2/3rds of an ORM).
So replace it with a custom made version table.

Had to change the version decorator slightly for this

app/dao/dao_utils.py

@@ -1,6 +1,7 @@
 import itertools
-from functools import wraps
-from app.history_meta import versioned_objects, create_history
+from functools import wraps, partial
+
+from app.history_meta import create_history
 
 
 def transactional(func):
@@ -19,14 +20,16 @@ def transactional(func):
     return commit_or_rollback
 
 
-def version_class(model_class):
+def version_class(model_class, history_cls=None):
+    create_hist = partial(create_history, history_cls=history_cls)
+
     def versioned(func):
         @wraps(func)
         def record_version(*args, **kwargs):
             from app import db
             func(*args, **kwargs)
-            history_objects = [create_history(obj) for obj in
-                               versioned_objects(itertools.chain(db.session.new, db.session.dirty))
+            history_objects = [create_hist(obj) for obj in
+                               itertools.chain(db.session.new, db.session.dirty)
                                if isinstance(obj, model_class)]
             for h_obj in history_objects:
                 db.session.add(h_obj)

app/dao/services_dao.py

@@ -16,6 +16,7 @@ from app.models import (
     VerifyCode,
     ApiKey,
     Template,
+    TemplateHistory,
     Job,
     NotificationHistory,
     Notification,
@@ -122,7 +123,7 @@ def delete_service_and_all_associated_db_objects(service):
     _delete_commit(Notification.query.filter_by(service=service))
     _delete_commit(Job.query.filter_by(service=service))
     _delete_commit(Template.query.filter_by(service=service))
-    _delete_commit(Template.get_history_model().query.filter_by(service_id=service.id))
+    _delete_commit(TemplateHistory.query.filter_by(service_id=service.id))
 
     verify_codes = VerifyCode.query.join(User).filter(User.id.in_([x.id for x in service.users]))
     list(map(db.session.delete, verify_codes))

app/dao/templates_dao.py

@@ -1,8 +1,9 @@
 import uuid
-from app import db
-from app.models import (Template, Service)
+
 from sqlalchemy import (asc, desc)
 
+from app import db
+from app.models import (Template, TemplateHistory)
 from app.dao.dao_utils import (
     transactional,
     version_class
@@ -10,7 +11,7 @@ from app.dao.dao_utils import (
 
 
 @transactional
-@version_class(Template)
+@version_class(Template, TemplateHistory)
 def dao_create_template(template):
     template.id = uuid.uuid4()  # must be set now so version history model can use same id
     template.archived = False
@@ -18,14 +19,14 @@ def dao_create_template(template):
 
 
 @transactional
-@version_class(Template)
+@version_class(Template, TemplateHistory)
 def dao_update_template(template):
     db.session.add(template)
 
 
 def dao_get_template_by_id_and_service_id(template_id, service_id, version=None):
     if version is not None:
-        return Template.get_history_model().query.filter_by(
+        return TemplateHistory.query.filter_by(
             id=template_id,
             service_id=service_id,
             version=version).one()
@@ -34,7 +35,7 @@ def dao_get_template_by_id_and_service_id(template_id, service_id, version=None)
 
 def dao_get_template_by_id(template_id, version=None):
     if version is not None:
-        return Template.get_history_model().query.filter_by(
+        return TemplateHistory.query.filter_by(
             id=template_id,
             version=version).one()
     return Template.query.filter_by(id=template_id).one()
@@ -50,6 +51,8 @@ def dao_get_all_templates_for_service(service_id):
 
 
 def dao_get_template_versions(service_id, template_id):
-    history_model = Template.get_history_model()
-    return history_model.query.filter_by(service_id=service_id, id=template_id).order_by(
-        desc(history_model.version)).all()
+    return TemplateHistory.query.filter_by(
+        service_id=service_id, id=template_id
+    ).order_by(
+        desc(TemplateHistory.version)
+    ).all()

app/history_meta.py

@@ -171,17 +171,13 @@ class Versioned(object):
         return history_mapper.class_
 
 
-def versioned_objects(iter):
-    for obj in iter:
-        if hasattr(obj, '__history_mapper__'):
-            yield obj
+def create_history(obj, history_cls=None):
+    if not history_cls:
+        history_mapper = obj.__history_mapper__
+        history_cls = history_mapper.class_
 
-
-def create_history(obj):
-    obj_mapper = object_mapper(obj)
-    history_mapper = obj.__history_mapper__
-    history_cls = history_mapper.class_
     history = history_cls()
+    obj_mapper = object_mapper(obj)
 
     obj_state = attributes.instance_state(obj)
     data = {}

app/models.py

@@ -206,7 +206,7 @@ TEMPLATE_TYPES = [SMS_TYPE, EMAIL_TYPE, LETTER_TYPE]
 template_types = db.Enum(*TEMPLATE_TYPES, name='template_type')
 
 
-class Template(db.Model, Versioned):
+class Template(db.Model):
     __tablename__ = 'templates'
 
     id = db.Column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
@@ -231,6 +231,26 @@ class Template(db.Model, Versioned):
     subject = db.Column(db.Text, index=False, unique=False, nullable=True)
     created_by_id = db.Column(UUID(as_uuid=True), db.ForeignKey('users.id'), index=True, nullable=False)
     created_by = db.relationship('User')
+    version = db.Column(db.Integer, default=1)
+
+
+class TemplateHistory(db.Model):
+    __tablename__ = 'templates_history'
+
+    id = db.Column(UUID(as_uuid=True), primary_key=True)
+    name = db.Column(db.String(255), nullable=False)
+    template_type = db.Column(template_types, nullable=False)
+    created_at = db.Column(db.DateTime, nullable=False)
+    updated_at = db.Column(db.DateTime)
+    content = db.Column(db.Text, nullable=False)
+    archived = db.Column(db.Boolean, nullable=False, default=False)
+    service_id = db.Column(UUID(as_uuid=True), db.ForeignKey('services.id'), index=True, nullable=False)
+    service = db.relationship('Service')
+    subject = db.Column(db.Text)
+    created_by_id = db.Column(UUID(as_uuid=True), db.ForeignKey('users.id'), index=True, nullable=False)
+    created_by = db.relationship('User')
+    version = db.Column(db.Integer)
+
 
 MMG_PROVIDER = "mmg"
 FIRETEXT_PROVIDER = "firetext"

app/service/rest.py

@@ -189,7 +189,7 @@ def get_service_history(service_id):
     api_key_history = ApiKey.get_history_model().query.filter_by(service_id=service_id).all()
     api_keys_data = api_key_history_schema.dump(api_key_history, many=True).data
 
-    template_history = Template.get_history_model().query.filter_by(service_id=service_id).all()
+    template_history = TemplateHistory.query.filter_by(service_id=service_id).all()
     template_data, errors = template_history_schema.dump(template_history, many=True)
 
     events = Event.query.all()

tests/app/dao/test_services_dao.py

@@ -331,7 +331,7 @@ def test_delete_service_and_associated_objects(notify_db,
     assert ApiKey.query.count() == 0
     assert ApiKey.get_history_model().query.count() == 0
     assert Template.query.count() == 0
-    assert Template.get_history_model().query.count() == 0
+    assert TemplateHistory.query.count() == 0
     assert Job.query.count() == 0
     assert Notification.query.count() == 0
     assert Permission.query.count() == 0

tests/app/dao/test_templates_dao.py

@@ -185,7 +185,7 @@ def test_get_template_by_id_and_service_returns_none_if_no_template(sample_servi
 
 def test_create_template_creates_a_history_record_with_current_data(sample_service, sample_user):
     assert Template.query.count() == 0
-    assert Template.get_history_model().query.count() == 0
+    assert TemplateHistory.query.count() == 0
     data = {
         'name': 'Sample Template',
         'template_type': "email",
@@ -200,7 +200,7 @@ def test_create_template_creates_a_history_record_with_current_data(sample_servi
     assert Template.query.count() == 1
 
     template_from_db = Template.query.first()
-    template_history = Template.get_history_model().query.first()
+    template_history = TemplateHistory.query.first()
 
     assert template_from_db.id == template_history.id
     assert template_from_db.name == template_history.name
@@ -212,7 +212,7 @@ def test_create_template_creates_a_history_record_with_current_data(sample_servi
 
 def test_update_template_creates_a_history_record_with_current_data(sample_service, sample_user):
     assert Template.query.count() == 0
-    assert Template.get_history_model().query.count() == 0
+    assert TemplateHistory.query.count() == 0
     data = {
         'name': 'Sample Template',
         'template_type': "email",
@@ -228,20 +228,20 @@ def test_update_template_creates_a_history_record_with_current_data(sample_servi
     assert created.name == 'Sample Template'
     assert Template.query.count() == 1
     assert Template.query.first().version == 1
-    assert Template.get_history_model().query.count() == 1
+    assert TemplateHistory.query.count() == 1
 
     created.name = 'new name'
     dao_update_template(created)
 
     assert Template.query.count() == 1
-    assert Template.get_history_model().query.count() == 2
+    assert TemplateHistory.query.count() == 2
 
     template_from_db = Template.query.first()
 
     assert template_from_db.version == 2
 
-    assert Template.get_history_model().query.filter_by(name='Sample Template').one().version == 1
-    assert Template.get_history_model().query.filter_by(name='new name').one().version == 2
+    assert TemplateHistory.query.filter_by(name='Sample Template').one().version == 1
+    assert TemplateHistory.query.filter_by(name='new name').one().version == 2
 
 
 def test_get_template_history_version(sample_user, sample_service, sample_template):