Database schema change and new UI feature. The user can now rearrange the products.

* Product has a new 'order' column.
* The user can now specify the sort order at product creation time with the
  'product add --sort INT' command.
* The user can now rearrange the products with the 'products set --sort INT'
  comand.
* The user can now show a sorted list of products in cli.py with the
  'product list --sort' command.

cli.py

@@ -224,26 +224,37 @@ def product():
 
 
 def tabulate_products(products):
-    tab = [["UID", "Name", "Price", "Enabled", "Created at"]]
+    tab = [["UID", "Name", "Price", "Sort", "Enabled", "Created at"]]
     for p in products:
-        tab.append([p.uid, p.name, p.price, p.is_active, p.created_at])
+        tab.append([p.uid, p.name, p.price, p.sort, p.is_active, p.created_at])
     return tabulate(tab, headers='firstrow')
 
 
 @product.command('add')
 @click.argument('name')
 @click.argument('price')
-def product_add(name, price):
+@click.option('-s', '--sort', type=click.INT)
+def product_add(name, price, sort):
     product = Product(name=name, price=price)
+
+    if sort:
+        product.sort = sort
+
     with db.get_session() as session:
         session.add(product)
     print("Product successfully added.")
 
 
 @product.command('list')
-def product_list():
+@click.option('-s', '--sort', is_flag=True)
+def product_list(sort):
     with db.get_session() as session:
-        products = session.query(Product).all()
+        products = session.query(Product)
+
+        if sort:
+            products = products.order_by(Product.sort.asc())
+
+        products = products.all()
 
     if products:
         print(tabulate_products(products))
@@ -251,6 +262,35 @@ def product_list():
         print("No products found.")
 
 
+@product.command('set')
+@click.option('-n', '--name')
+@click.option('-p', '--price', type=click.INT)
+@click.option('-s', '--sort', type=click.INT)
+@click.argument('product_uid')
+def product_set(product_uid, name, price, sort):
+    with db.get_session() as session:
+        product = session.query(Product).get(product_uid)
+
+    if not product:
+        print("No product found with id #{}.".format(product_uid))
+        return
+
+    if name:
+        product.name = name
+
+    if price:
+        product.price = price
+
+    if sort:
+        product.sort = sort
+
+    if any([name, price, sort]):
+        with db.get_session() as session:
+            session.add(product)
+        print("Event successfully edited.")
+        print(tabulate_products([product]))
+
+
 @cli.group('transaction')
 def transaction():
     pass

pos/database.py

@@ -118,6 +118,7 @@ class Product(Base):
     uid = Column(Integer, primary_key=True)
     name = Column(String, nullable=False)
     price = Column(Integer, nullable=False)
+    sort = Column(Integer, nullable=False, server_default='0')
     created_at = Column(DateTime, nullable=False, default=datetime.now)
     is_active = Column(Boolean, nullable=False, server_default='1')
 

web.py

@@ -87,6 +87,7 @@ def logout():
 def get_products(session):
     return session.query(Product)\
                   .filter(Product.is_active == 1)\
+                  .order_by(Product.sort.asc())\
                   .all()