Avoid user assigning unimplemented fields on containers.

Before:

    doc.trade.settlement.payment_means.type_code = "30"

was allowed but had no effect as payemnt_means is a container.

Now it gives:

    Traceback (most recent call last):
      File "/home/mdk/src/python-drafthorse/test.py", line 54, in <module>
        doc.trade.settlement.payment_means.type_code = "30"  # Virement
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    AttributeError: 'Container' object has no attribute 'type_code' and no __dict__ for setting new attributes

Author: JulienPalard

drafthorse/models/container.py

@@ -1,4 +1,6 @@
 class Container:
+    __slots__ = ("children", "child_type")
+
     def __init__(self, child_type):
         super().__init__()
         self.children = []
@@ -26,6 +28,8 @@ def add_from_etree(self, root, strict=True):
 
 
 class SimpleContainer(Container):
+    __slots__ = ("children", "child_type", "namespace", "tag")
+
     def __init__(self, child_type, namespace, tag):
         super().__init__(child_type)
         self.namespace = namespace
@@ -51,6 +55,8 @@ def add_from_etree(self, root, strict=True):
 
 
 class CurrencyContainer(SimpleContainer):
+    __slots__ = ("children", "child_type", "namespace", "tag")
+
     def empty_element(self):
         from .elements import CurrencyElement
 
@@ -65,6 +71,8 @@ def add_from_etree(self, root, strict=True):
 
 
 class IDContainer(SimpleContainer):
+    __slots__ = ("children", "child_type", "namespace", "tag")
+
     def empty_element(self):
         from .elements import IDElement
 
@@ -79,6 +87,8 @@ def add_from_etree(self, root, strict=True):
 
 
 class StringContainer(SimpleContainer):
+    __slots__ = ("children", "child_type", "namespace", "tag")
+
     def empty_element(self):
         from .elements import StringElement
 

tests/conftest.py

@@ -7,6 +7,8 @@
 from drafthorse.models.document import Document
 from drafthorse.models.note import IncludedNote
 from drafthorse.models.party import TaxRegistration
+from drafthorse.models.payment import PaymentMeans
+from drafthorse.models.trade import AdvancePayment, IncludedTradeTax
 from drafthorse.models.tradelines import LineItem
 
 
@@ -31,7 +33,7 @@ def invoice_document(request):
     doc.trade.settlement.invoicee.name = "Kunde GmbH"
 
     doc.trade.settlement.currency_code = "EUR"
-    doc.trade.settlement.payment_means.type_code = "ZZZ"
+    doc.trade.settlement.payment_means.add(PaymentMeans(type_code="ZZZ"))
 
     doc.trade.agreement.seller.address.country_id = "DE"
     doc.trade.agreement.seller.address.country_subdivision = "Bayern"
@@ -41,7 +43,18 @@ def invoice_document(request):
 
     doc.trade.agreement.seller_order.issue_date_time = datetime.now(timezone.utc)
     doc.trade.agreement.buyer_order.issue_date_time = datetime.now(timezone.utc)
-    doc.trade.settlement.advance_payment.received_date = datetime.now(timezone.utc)
+    advance = AdvancePayment(
+        received_date=datetime.now(timezone.utc), paid_amount=Decimal(42)
+    )
+    advance.included_trade_tax.add(
+        IncludedTradeTax(
+            calculated_amount=Decimal(0),
+            type_code="VAT",
+            category_code="E",
+            rate_applicable_percent=Decimal(0),
+        )
+    )
+    doc.trade.settlement.advance_payment.add(advance)
     doc.trade.agreement.customer_order.issue_date_time = datetime.now(timezone.utc)
 
     li = LineItem()