Improvement/tag type constraint (#1255)

* Switching from autocomplete component to combobox component

* ensuring that tag type is not nullable

src/dispatch/alembic/versions/f011c050b9ba_.py

@@ -0,0 +1,73 @@
+"""Ensures we always have a tag type
+
+Revision ID: f011c050b9ba
+Revises: 3e5f024e72f4
+Create Date: 2021-06-01 10:33:32.006080
+
+"""
+from alembic import op
+import sqlalchemy as sa
+from datetime import datetime
+
+from sqlalchemy.orm import relationship, Session
+
+from sqlalchemy.ext.declarative import declarative_base, declared_attr
+
+Base = declarative_base()
+
+
+# revision identifiers, used by Alembic.
+revision = "f011c050b9ba"
+down_revision = "3e5f024e72f4"
+branch_labels = None
+depends_on = None
+
+
+class ProjectMixin(object):
+    """Project mixin"""
+
+    @declared_attr
+    def project_id(cls):  # noqa
+        return sa.Column(sa.Integer)
+
+
+class TimeStampMixin(object):
+    """Timestamping mixin"""
+
+    created_at = sa.Column(sa.DateTime, default=datetime.utcnow)
+    created_at._creation_order = 9998
+    updated_at = sa.Column(sa.DateTime, default=datetime.utcnow)
+    updated_at._creation_order = 9998
+
+    @staticmethod
+    def _updated_at(mapper, connection, target):
+        target.updated_at = datetime.utcnow()
+
+    @classmethod
+    def __declare_last__(cls):
+        sa.event.listen(cls, "before_update", cls._updated_at)
+
+
+class TagType(Base, TimeStampMixin, ProjectMixin):
+    __tablename__ = "tag_type"
+    id = sa.Column(sa.Integer, primary_key=True)
+    name = sa.Column(sa.String)
+    description = sa.Column(sa.String)
+
+
+def upgrade():
+    bind = op.get_bind()
+    session = Session(bind=bind)
+
+    default_tag_type = TagType(
+        name="default", description="Default dispatch tag type.", project_id=1
+    )
+    session.add(default_tag_type)
+    session.flush()
+
+    op.execute("update tag set tag_type_id = 1 where tag_type_id is null;")
+    op.alter_column("tag", "tag_type_id", existing_type=sa.INTEGER(), nullable=False)
+
+
+def downgrade():
+    op.alter_column("tag", "tag_type_id", existing_type=sa.INTEGER(), nullable=True)

src/dispatch/tag/models.py

@@ -23,7 +23,7 @@ class Tag(Base, TimeStampMixin, ProjectMixin):
     discoverable = Column(Boolean, default=True)
 
     # Relationships
-    tag_type_id = Column(Integer, ForeignKey("tag_type.id"))
+    tag_type_id = Column(Integer, ForeignKey("tag_type.id"), nullable=False)
     tag_type = relationship("TagType", backref="tag")
 
     search_vector = Column(TSVectorType("name"))