def write_choice(self, value: Any, var: XmlVar,
namespace: NoneStr) -> Generator:
"""
Produce an events stream for the given value of a compound elements
field.
The value can be anything as long as we can match the qualified
name or its type to a choice.
"""
if isinstance(value, DerivedElement):
choice = var.find_choice(value.qname)
value = value.value
func = self.write_xsi_type if is_dataclass(
value) else self.write_element
elif isinstance(value, AnyElement) and value.qname:
choice = var.find_choice(value.qname)
func = self.write_any_type
else:
choice = var.find_value_choice(value)
func = self.write_value
if not choice:
raise SerializerError(
f"XmlElements undefined choice: `{var.name}` for `{type(value)}`"
)
yield from func(value, choice, namespace)
def test_find_choice(self):
choices = [
XmlVar(element=True, name="a", qname="{a}a"),
XmlVar(element=True, name="b", qname="b"),
]
var = XmlVar(elements=True, name="foo", qname="foo", choices=choices)
self.assertFalse(var.matches("a"))
self.assertIsNone(var.find_choice("a"))
self.assertEqual(choices[0], var.find_choice("{a}a"))
self.assertTrue(var.matches("{a}a"))
self.assertEqual(choices[1], var.find_choice("b"))
self.assertTrue(var.matches("b"))
def bind_choice_generic(self, value: Dict, var: XmlVar) -> Any:
"""Bind data to a either a derived or a user derived model."""
qname = value["qname"]
choice = var.find_choice(qname)
if not choice:
raise ParserError(
f"XmlElements undefined choice: `{var.name}` for qname `{qname}`"
)
if "value" in value:
return DerivedElement(qname,
self.bind_value(choice, value["value"]))
return self.bind_dataclass(value, AnyElement)