Generate slug in app

app/migrations/versions/29ccbe077c57_add_slug.py

@@ -24,22 +24,7 @@ def upgrade():
     ))
     op.create_unique_constraint('order_slug_unique', 'order', ['slug'])
 
-    # Trigger to handle duplicates: generate new slug if slug already exists
-    op.execute(text(
-        """
-        CREATE TRIGGER order_before_insert
-          BEFORE UPDATE ON `order`
-          FOR EACH ROW
-          BEGIN
-            WHILE (NEW.slug IS NULL OR (SELECT id FROM `order` WHERE slug = NEW.slug) IS NOT NULL) DO
-              SET NEW.slug = SUBSTRING(MD5(RAND()) FROM 1 FOR 7);
-            END WHILE;
-          END
-        """
-    ))
-
 
 def downgrade():
-    op.execute(text("DROP TRIGGER order_before_insert"))
     op.drop_constraint('order_slug_unique', 'order', type_='unique')
     op.drop_column('order', 'slug')

app/models/order.py

@@ -2,6 +2,7 @@
 import typing
 from collections import defaultdict
 from datetime import datetime
+import secrets
 import string
 
 from hlds.definitions import location_definitions
@@ -10,6 +11,12 @@ from utils import first
 from .database import db
 from .user import User
 
+def generate_slug():
+    alphabet = string.ascii_letters + string.digits
+    secret = ''.join(secrets.choice(alphabet) for i in range(7))
+    while Order.query.filter(Order.slug == secret).first() is not None:
+        secret = ''.join(secrets.choice(alphabet) for i in range(7))
+    return secret
 
 class Order(db.Model):
     """Class used for configuring the Order model in the database"""
@@ -20,9 +27,7 @@ class Order(db.Model):
     starttime = db.Column(db.DateTime)
     stoptime = db.Column(db.DateTime)
     public = db.Column(db.Boolean, default=True)
-    # The default value for `slug`, a random 7-character alphanumerical string,
+    slug = db.Column(db.String(7), default=generate_slug, unique=True)
-    # is created on the database side. See migrations/versions/29ccbe077c57_add_slug.py
-    slug = db.Column(db.String(7), unique=True)
     association = db.Column(db.String(120), nullable=False, server_default="")
 
     items = db.relationship("OrderItem", backref="order", lazy="dynamic")