# Copyright (c) 2010-2024 openpyxl
from openpyxl.compat import safe_string
from openpyxl.xml.functions import Element
from openpyxl.utils.indexed_list import IndexedList
from .base import Descriptor, Alias, _convert
from .namespace import namespaced
[docs]
class Sequence(Descriptor):
"""
A sequence (list or tuple) that may only contain objects of the declared
type
"""
expected_type = type(None)
seq_types = (list, tuple)
idx_base = 0
unique = False
container = list
def __set__(self, instance, seq):
if not isinstance(seq, self.seq_types):
raise TypeError("Value must be a sequence")
seq = self.container(_convert(self.expected_type, value) for value in seq)
if self.unique:
seq = IndexedList(seq)
super().__set__(instance, seq)
[docs]
def to_tree(self, tagname, obj, namespace=None):
"""
Convert the sequence represented by the descriptor to an XML element
"""
for idx, v in enumerate(obj, self.idx_base):
if hasattr(v, "to_tree"):
el = v.to_tree(tagname, idx)
else:
tagname = namespaced(obj, tagname, namespace)
el = Element(tagname)
el.text = safe_string(v)
yield el
[docs]
class UniqueSequence(Sequence):
"""
Use a set to keep values unique
"""
seq_types = (list, tuple, set)
container = set
[docs]
class ValueSequence(Sequence):
"""
A sequence of primitive types that are stored as a single attribute.
"val" is the default attribute
"""
attribute = "val"
[docs]
def to_tree(self, tagname, obj, namespace=None):
tagname = namespaced(self, tagname, namespace)
for v in obj:
yield Element(tagname, {self.attribute:safe_string(v)})
[docs]
def from_tree(self, node):
return node.get(self.attribute)
[docs]
class NestedSequence(Sequence):
"""
Wrap a sequence in an containing object
"""
count = False
[docs]
def to_tree(self, tagname, obj, namespace=None):
tagname = namespaced(self, tagname, namespace)
container = Element(tagname)
if self.count:
container.set('count', str(len(obj)))
for v in obj:
container.append(v.to_tree())
return container
[docs]
def from_tree(self, node):
return [self.expected_type.from_tree(el) for el in node]
[docs]
class MultiSequence(Sequence):
"""
Sequences can contain objects with different tags
"""
def __set__(self, instance, seq):
if not isinstance(seq, (tuple, list)):
raise ValueError("Value must be a sequence")
seq = list(seq)
Descriptor.__set__(self, instance, seq)
[docs]
def to_tree(self, tagname, obj, namespace=None):
"""
Convert the sequence represented by the descriptor to an XML element
"""
for v in obj:
el = v.to_tree(namespace=namespace)
yield el
[docs]
class MultiSequencePart(Alias):
"""
Allow a multisequence to be built up from parts
Excluded from the instance __elements__ or __attrs__ as is effectively an Alias
"""
def __init__(self, expected_type, store):
self.expected_type = expected_type
self.store = store
def __set__(self, instance, value):
value = _convert(self.expected_type, value)
instance.__dict__[self.store].append(value)
def __get__(self, instance, cls):
return self
