Source code for xsdata.formats.dataclass.parsers.utils

from dataclasses import is_dataclass
from typing import Any
from typing import Dict
from typing import List
from typing import Optional
from typing import Tuple
from typing import Type

from lxml.etree import Element
from lxml.etree import QName

from xsdata.exceptions import ParserError
from xsdata.formats.converters import to_python
from xsdata.formats.dataclass.models.elements import FindMode
from xsdata.formats.dataclass.models.elements import XmlMeta
from xsdata.formats.dataclass.models.elements import XmlVar
from xsdata.formats.dataclass.models.generics import AnyElement
from xsdata.logger import logger
from xsdata.models.enums import QNames
from xsdata.utils import text


[docs]class ParserUtils:
[docs] @classmethod def parse_xsi_type(cls, element: Element) -> Optional[QName]: """Parse the elements xsi:type attribute if present.""" xsi_type = element.attrib.get(QNames.XSI_TYPE) return ( cls.parse_value([QName], xsi_type, None, element.nsmap) if xsi_type else None )
[docs] @classmethod def parse_value( cls, types: List[Type], value: Any, default: Any = None, ns_map: Optional[Dict] = None, tokens: bool = False, ) -> Any: """Convert xml string values to s python primitive type.""" if value is None: return None if callable(default) else default if tokens: value = value if isinstance(value, list) else filter(None, value.split(" ")) return list(map(lambda x: to_python(types, x, ns_map), value)) return to_python(types, value, ns_map)
[docs] @classmethod def bind_element_children( cls, params: Dict, meta: XmlMeta, position: int, objects: List, ): """Return a dictionary of qualified object names and their values for the given queue item.""" while len(objects) > position: qname, value = objects.pop(position) arg = meta.find_var(qname, FindMode.NOT_WILDCARD) or meta.find_var( qname, FindMode.WILDCARD ) if not arg: raise ParserError("Impossible exception!") if not arg.init: continue if value is None: value = "" if not cls.bind_element_param(params, arg, value): lookup = QName(value.qname) if isinstance(value, AnyElement) else qname wild = cls.find_eligible_wildcard(meta, lookup, params) if not wild: logger.warning("Unassigned parsed object %s", qname) else: cls.bind_element_wildcard_param(params, wild, qname, value)
[docs] @classmethod def fetch_any_children(cls, position: int, objects: List) -> List[object]: """Fetch the children of a wildcard node.""" children = [] while len(objects) > position: _, value = objects.pop(position) children.append(value) return children
[docs] @classmethod def bind_element_param(cls, params: Dict, var: XmlVar, value: Any) -> bool: """ Add the given value to the params dictionary with the var name as key. Wrap the value to a list if var is a list. If the var name already exists it means we have a name conflict and the parser needs to lookup for any available wildcard fields. :return: Whether the binding process was successful or not. """ if var.is_list: params.setdefault(var.name, []).append(value) elif var.name not in params: params[var.name] = value else: return False return True
[docs] @classmethod def bind_element_wildcard_param( cls, params: Dict, var: XmlVar, qname: QName, value: Any ): """ Add the given value to the params dictionary with the wildcard var name as key. If the key is already present wrap the previous value into a generic AnyElement instance. If the previous value is already a generic instance add the current value as a child object. """ if is_dataclass(value): if not isinstance(value, AnyElement): value.qname = qname else: value = AnyElement(qname=qname, text=value) if var.name in params: previous = params[var.name] if previous.qname: params[var.name] = AnyElement(children=[previous]) params[var.name].children.append(value) else: params[var.name] = value
[docs] @classmethod def bind_element_wild_text(cls, params: Dict, meta: XmlMeta, element: Element): """ Extract the text and tail content and bind it accordingly in the params dictionary. - var is a list prepend the text and append the tail. - var is present in the params assign the text and tail to the generic object. - Otherwise bind the given element to a new generic object. """ var = meta.find_var(mode=FindMode.WILDCARD) if not var: return txt, tail = cls.element_text_and_tail(element) if not txt and not tail: return if var.is_list: if var.name not in params: params[var.name] = [] if txt: params[var.name].insert(0, txt) if tail: params[var.name].append(tail) elif var.name in params: params[var.name].text = txt params[var.name].tail = tail else: params[var.name] = cls.parse_any_element(element, False)
[docs] @classmethod def element_text_and_tail(cls, element: Element) -> Tuple: """Extract the text and tail content if any and return them both.""" txt = element.text.strip() if element.text else None tail = element.tail.strip() if element.tail else None return txt or None, tail or None
[docs] @classmethod def parse_any_element(cls, element: Element, qname: bool = True) -> AnyElement: """Bind the given element content to a new generic object.""" txt, tail = cls.element_text_and_tail(element) return AnyElement( qname=element.tag if qname else None, text=txt, tail=tail, ns_map=element.nsmap, attributes=cls.parse_any_attributes(element), )
[docs] @classmethod def parse_any_attributes(cls, element: Element) -> Dict[QName, Any]: """Extract the given element's attributes into the dictionary with keys the fully qualified attribute names.""" def qname(value: Any) -> Any: prefix, suffix = text.split(value) if prefix and prefix in element.nsmap: return QName(element.nsmap[prefix], suffix) return value return {QName(key): qname(value) for key, value in element.attrib.items()}
[docs] @classmethod def bind_element_text(cls, params: Dict, metadata: XmlMeta, element: Element): """Add the given element's text content if any to the params dictionary with the text var name as key.""" var = metadata.find_var(mode=FindMode.TEXT) if var and element.text is not None and var.init: params[var.name] = cls.parse_value( var.types, element.text, var.default, element.nsmap, var.is_tokens )
[docs] @classmethod def bind_element_attrs(cls, params: Dict, metadata: XmlMeta, element: Element): """Parse the given element's attributes and any text content and return a dictionary of field names and values based on the given class metadata.""" if not element.attrib: return wildcard = metadata.find_var(mode=FindMode.ATTRIBUTES) for key, value in element.attrib.items(): var = metadata.find_var(QName(key), FindMode.ATTRIBUTE) if var and var.name not in params: if var.init: params[var.name] = cls.parse_value( var.types, value, var.default, element.nsmap, var.is_tokens ) elif wildcard: if wildcard.name not in params: params[wildcard.name] = {} params[wildcard.name][key] = value
[docs] @classmethod def find_eligible_wildcard( cls, meta: XmlMeta, qname: QName, params: Dict ) -> Optional[XmlVar]: """ Last resort lookup for a suitable wildcard var. Search for a list wildcard or a wildcard that already exists in the params dictionary. """ return next( ( var for var in meta.vars if var.is_wildcard and var.matches(qname) and ( (var.is_list or var.name not in params) or (not var.is_list and var.name in params) ) ), None, )