def activate_basic_check_credit_rules():
"""
Issues function calls to activate check credit rules, below.
These rules are executed not now, but on commits
Order is irrelevant - determined by system based on dependency analysis
Their inclusion in classes is for doc / convenience, no semantics
These rules apply to all transactions (automatic re-use), eg.
* place order
* change Order Detail product, quantity
* add/delete Order Detail
* ship / unship order
* delete order
* move order to new customer, etc
"""
def units_in_stock(row: Product, old_row: Product, logic_row: LogicRow):
result = row.UnitsInStock - (row.UnitsShipped - old_row.UnitsShipped)
return result
def congratulate_sales_rep(row: Order, old_row: Order, logic_row: LogicRow):
if logic_row.ins_upd_dlt == "ins" or True: # logic engine fills parents for insert
sales_rep = row.SalesRep # type : Employee
if sales_rep is None:
logic_row.log("no salesrep for this order")
else:
logic_row.log(f'Hi, {sales_rep.Manager.FirstName}, congratulate {sales_rep.FirstName} on their new order')
Rule.constraint(validate=Customer,
as_condition=lambda row: row.Balance <= row.CreditLimit,
error_msg="balance ({row.Balance}) exceeds credit ({row.CreditLimit})")
Rule.sum(derive=Customer.Balance, as_sum_of=Order.AmountTotal,
where=lambda row: row.ShippedDate is None) # *not* a sql select sum...
Rule.sum(derive=Order.AmountTotal, as_sum_of=OrderDetail.Amount)
Rule.formula(derive=OrderDetail.Amount, as_expression=lambda row: row.UnitPrice * row.Quantity)
Rule.copy(derive=OrderDetail.UnitPrice, from_parent=Product.UnitPrice)
Rule.formula(derive=OrderDetail.ShippedDate, as_exp="row.OrderHeader.ShippedDate")
Rule.sum(derive=Product.UnitsShipped, as_sum_of=OrderDetail.Quantity,
where="row.ShippedDate is not None")
Rule.formula(derive=Product.UnitsInStock, calling=units_in_stock)
Rule.commit_row_event(on_class=Order, calling=congratulate_sales_rep)
Rule.count(derive=Customer.UnpaidOrderCount, as_count_of=Order,
where=lambda row: row.ShippedDate is None) # *not* a sql select sum...
Rule.count(derive=Customer.OrderCount, as_count_of=Order)
def declare_logic():
"""
Issues function calls to activate rules for check credit (etc), below.
These rules are executed not now, but on commits
Order is irrelevant - determined by system based on dependency analysis
Their inclusion in classes is for doc / convenience, no semantics
These rules apply to all transactions (automatic re-use), eg.
* place order
* change Order Detail product, quantity
* add/delete Order Detail
* ship / unship order
* delete order
* move order to new customer, etc
Activate rules like this
LogicBank.activate(session=session, activator=declare_logic)
"""
def congratulate_sales_rep(row: Order, old_row: Order, logic_row: LogicRow):
if logic_row.ins_upd_dlt == "ins": # logic engine fills parents for insert
sales_rep = row.SalesRep # type : Employee
if sales_rep is None:
logic_row.log("no salesrep for this order")
else:
logic_row.log(f'Hi, {sales_rep.Manager.FirstName}, congratulate {sales_rep.FirstName} on their new order')
Rule.constraint(validate=Customer,
as_condition=lambda row: row.Balance <= row.CreditLimit,
error_msg="balance ({row.Balance}) exceeds credit ({row.CreditLimit})")
Rule.sum(derive=Customer.Balance, as_sum_of=Order.AmountTotal,
where=lambda row: row.ShippedDate is None) # *not* a sql select sum...
Rule.sum(derive=Order.AmountTotal, as_sum_of=OrderDetail.Amount)
Rule.formula(derive=OrderDetail.Amount, as_expression=lambda row: row.UnitPrice * row.Quantity)
Rule.copy(derive=OrderDetail.UnitPrice, from_parent=Product.UnitPrice)
Rule.commit_row_event(on_class=Order, calling=congratulate_sales_rep)
Rule.formula(derive=OrderDetail.ShippedDate, as_exp="row.OrderHeader.ShippedDate")
def units_in_stock(row: Product, old_row: Product, logic_row: LogicRow):
result = row.UnitsInStock - (row.UnitsShipped - old_row.UnitsShipped)
return result
Rule.sum(derive=Product.UnitsShipped, as_sum_of=OrderDetail.Quantity,
where="row.ShippedDate is not None")
Rule.formula(derive=Product.UnitsInStock, calling=units_in_stock)
Rule.count(derive=Customer.UnpaidOrderCount, as_count_of=Order,
where=lambda row: row.ShippedDate is None) # *not* a sql select sum...
Rule.count(derive=Customer.OrderCount, as_count_of=Order)
Rule.constraint(validate=OrderClass,
as_condition=lambda row: row.Id <= 99999,
error_msg="Test constraint for className <> tableName")
Rule.constraint(validate=Employee,
as_condition=lambda row: row.IsCommissioned == 1 or row.order_count == 0,
error_msg="{row.LastName} is not commissioned - cannot have orders")
Rule.count(derive=Employee.order_count, as_count_of=Order)
def raise_over_20_percent(row: Employee, old_row: Employee, logic_row: LogicRow):
if logic_row.ins_upd_dlt == "upd" and row.Salary != old_row.Salary:
return row.Salary >= Decimal('1.20') * old_row.Salary
else:
return True
Rule.constraint(validate=Employee,
calling=raise_over_20_percent,
error_msg="{row.LastName} needs a more meaningful raise")
def audit_by_event(row: Employee, old_row: Employee, logic_row: LogicRow):
tedious = False # tedious code to repeat for every audited class
if tedious: # see instead the following rule extension - nw_copy_row
if logic_row.are_attributes_changed([Employee.Salary, Employee.Title]):
copy_to_logic_row = logic_row.new_logic_row(EmployeeAudit)
copy_to_logic_row.link(to_parent=logic_row)
copy_to_logic_row.set_same_named_attributes(logic_row)
copy_to_logic_row.insert(reason="Manual Copy " + copy_to_logic_row.name) # triggers rules...
# logic_row.log("audit_by_event (Manual Copy) complete")
Rule.commit_row_event(on_class=Employee, calling=audit_by_event)
""" also provided in system version
RuleExtension.copy(copy_from=Employee,
copy_to=EmployeeAudit,
copy_when=lambda logic_row: logic_row.are_attributes_changed([Employee.Salary, Employee.Title]))
"""
NWRuleExtension.nw_copy_row(copy_from=Employee,
copy_to=EmployeeAudit,
copy_when=lambda logic_row:
logic_row.are_attributes_changed([Employee.Salary, Employee.Title]))
def handle_all(logic_row: LogicRow):
row = logic_row.row
if logic_row.ins_upd_dlt == "ins" and hasattr(row, "CreatedOn"):
row.CreatedOn = datetime.datetime.now()
logic_row.log("early_row_event_all_classes - handle_all sets 'Created_on"'')
Rule.early_row_event_all_classes(early_row_event_all_classes=handle_all)