xml

xsdata.formats.dataclass.parsers.xml

XmlParser dataclass

Bases: NodeParser

Default Xml parser for data classes.

Parameters:

Name	Type	Description	Default
config	ParserConfig	The parser config instance	ParserConfig()
context	XmlContext	The xml context instance	XmlContext()
handler	type[XmlHandler]	The xml handler class	default_handler()

Attributes:

Name	Type	Description
ns_map	dict[str | None, str]	The parsed namespace prefix-URI map

Source code in xsdata/formats/dataclass/parsers/xml.py

@dataclass
class XmlParser(NodeParser):
    """Default Xml parser for data classes.

    Args:
        config: The parser config instance
        context: The xml context instance
        handler: The xml handler class

    Attributes:
        ns_map: The parsed namespace prefix-URI map
    """

    handler: type[XmlHandler] = field(default=default_handler())

UserXmlParser dataclass

Bases: NodeParser

Xml parser for dataclasses with hooks to events.

The event hooks allow custom parsers to inject custom logic between the start/end element events.

Parameters:

Name	Type	Description	Default
config	ParserConfig	The parser config instance	ParserConfig()
context	XmlContext	The xml context instance	XmlContext()
handler	type[XmlHandler]	The xml handler class	default_handler()

Attributes:

Name	Type	Description
ns_map	dict[str | None, str]	The parsed namespace prefix-URI map
hooks_cache	dict	The hooks cache is used to avoid inspecting the class for custom methods on duplicate events.

Source code in xsdata/formats/dataclass/parsers/xml.py

@dataclass
class UserXmlParser(NodeParser):
    """Xml parser for dataclasses with hooks to events.

    The event hooks allow custom parsers to inject custom
    logic between the start/end element events.

    Args:
        config: The parser config instance
        context: The xml context instance
        handler: The xml handler class

    Attributes:
        ns_map: The parsed namespace prefix-URI map
        hooks_cache: The hooks cache is used to avoid
            inspecting the class for custom methods
            on duplicate events.
    """

    handler: type[XmlHandler] = field(default=default_handler())
    hooks_cache: dict = field(init=False, default_factory=dict)

    def start(
        self,
        clazz: type | None,
        queue: list[XmlNode],
        objects: list[Parsed],
        qname: str,
        attrs: dict,
        ns_map: dict,
    ) -> None:
        """Build and queue the XmlNode for the starting element.

        Override to emit the start element event.

        Args:
            clazz: The target class type, auto locate if omitted
            queue: The XmlNode queue list
            objects: The list of all intermediate parsed objects
            qname: The element qualified name
            attrs: The element attributes
            ns_map: The element namespace prefix-URI map
        """
        super().start(clazz, queue, objects, qname, attrs, ns_map)
        self.emit_event(EventType.START, qname, attrs=attrs)

    def end(
        self,
        queue: list[XmlNode],
        objects: list[Parsed],
        qname: str,
        text: str | None,
        tail: str | None,
    ) -> bool:
        """Parse the last xml node and bind any intermediate objects.

        Override to emit the end element event if the binding process
        is successful.

        Args:
            queue: The XmlNode queue list
            objects: The list of all intermediate parsed objects
            qname: The element qualified name
            text: The element text content
            tail: The element tail content

        Returns:
            Whether the binding process was successful.
        """
        result = super().end(queue, objects, qname, text, tail)
        if result:
            self.emit_event(EventType.END, qname, obj=objects[-1][1])
        return result

    def emit_event(self, event: str, name: str, **kwargs: Any) -> None:
        """Propagate event to subclasses.

        Match event and name to a subclass method and trigger it with
        any input keyword arguments.

        Example::
            event=start, name={urn}bookTitle -> start_booking_title(**kwargs)

        Args:
            event: The event type start|end
            name: The qualified name of the element
            kwargs: Additional keyword arguments passed to the hooks
        """
        key = (event, name)
        if key not in self.hooks_cache:
            method_name = f"{event}_{snake_case(local_name(name))}"
            self.hooks_cache[key] = getattr(self, method_name, None)

        method = self.hooks_cache[key]
        if method:
            method(**kwargs)

start(clazz, queue, objects, qname, attrs, ns_map)

Build and queue the XmlNode for the starting element.

Override to emit the start element event.

Parameters:

Name	Type	Description	Default
clazz	type | None	The target class type, auto locate if omitted	required
queue	list[XmlNode]	The XmlNode queue list	required
objects	list[Parsed]	The list of all intermediate parsed objects	required
qname	str	The element qualified name	required
attrs	dict	The element attributes	required
ns_map	dict	The element namespace prefix-URI map	required

Source code in xsdata/formats/dataclass/parsers/xml.py

def start(
    self,
    clazz: type | None,
    queue: list[XmlNode],
    objects: list[Parsed],
    qname: str,
    attrs: dict,
    ns_map: dict,
) -> None:
    """Build and queue the XmlNode for the starting element.

    Override to emit the start element event.

    Args:
        clazz: The target class type, auto locate if omitted
        queue: The XmlNode queue list
        objects: The list of all intermediate parsed objects
        qname: The element qualified name
        attrs: The element attributes
        ns_map: The element namespace prefix-URI map
    """
    super().start(clazz, queue, objects, qname, attrs, ns_map)
    self.emit_event(EventType.START, qname, attrs=attrs)

end(queue, objects, qname, text, tail)

Parse the last xml node and bind any intermediate objects.

Override to emit the end element event if the binding process is successful.

Parameters:

Name	Type	Description	Default
queue	list[XmlNode]	The XmlNode queue list	required
objects	list[Parsed]	The list of all intermediate parsed objects	required
qname	str	The element qualified name	required
text	str | None	The element text content	required
tail	str | None	The element tail content	required

Returns:

Type	Description
bool	Whether the binding process was successful.

Source code in xsdata/formats/dataclass/parsers/xml.py

def end(
    self,
    queue: list[XmlNode],
    objects: list[Parsed],
    qname: str,
    text: str | None,
    tail: str | None,
) -> bool:
    """Parse the last xml node and bind any intermediate objects.

    Override to emit the end element event if the binding process
    is successful.

    Args:
        queue: The XmlNode queue list
        objects: The list of all intermediate parsed objects
        qname: The element qualified name
        text: The element text content
        tail: The element tail content

    Returns:
        Whether the binding process was successful.
    """
    result = super().end(queue, objects, qname, text, tail)
    if result:
        self.emit_event(EventType.END, qname, obj=objects[-1][1])
    return result

emit_event(event, name, **kwargs)

Propagate event to subclasses.

Match event and name to a subclass method and trigger it with any input keyword arguments.

Example:: event=start, name={urn}bookTitle -> start_booking_title(**kwargs)

Parameters:

Name	Type	Description	Default
event	str	The event type start|end	required
name	str	The qualified name of the element	required
kwargs	Any	Additional keyword arguments passed to the hooks	{}

Source code in xsdata/formats/dataclass/parsers/xml.py

def emit_event(self, event: str, name: str, **kwargs: Any) -> None:
    """Propagate event to subclasses.

    Match event and name to a subclass method and trigger it with
    any input keyword arguments.

    Example::
        event=start, name={urn}bookTitle -> start_booking_title(**kwargs)

    Args:
        event: The event type start|end
        name: The qualified name of the element
        kwargs: Additional keyword arguments passed to the hooks
    """
    key = (event, name)
    if key not in self.hooks_cache:
        method_name = f"{event}_{snake_case(local_name(name))}"
        self.hooks_cache[key] = getattr(self, method_name, None)

    method = self.hooks_cache[key]
    if method:
        method(**kwargs)