Updated script that can be controled by Nodejs web app

lib/python3.13/site-packages/openpyxl/packaging/relationship.py

@@ -0,0 +1,158 @@
+# Copyright (c) 2010-2024 openpyxl
+
+import posixpath
+from warnings import warn
+
+from openpyxl.descriptors import (
+    String,
+    Alias,
+    Sequence,
+)
+from openpyxl.descriptors.serialisable import Serialisable
+from openpyxl.descriptors.container import ElementList
+
+from openpyxl.xml.constants import REL_NS, PKG_REL_NS
+from openpyxl.xml.functions import (
+    Element,
+    fromstring,
+)
+
+
+class Relationship(Serialisable):
+    """Represents many kinds of relationships."""
+
+    tagname = "Relationship"
+
+    Type = String()
+    Target = String()
+    target = Alias("Target")
+    TargetMode = String(allow_none=True)
+    Id = String(allow_none=True)
+    id = Alias("Id")
+
+
+    def __init__(self,
+                 Id=None,
+                 Type=None,
+                 type=None,
+                 Target=None,
+                 TargetMode=None
+                 ):
+        """
+        `type` can be used as a shorthand with the default relationships namespace
+        otherwise the `Type` must be a fully qualified URL
+        """
+        if type is not None:
+            Type = "{0}/{1}".format(REL_NS, type)
+        self.Type = Type
+        self.Target = Target
+        self.TargetMode = TargetMode
+        self.Id = Id
+
+
+class RelationshipList(ElementList):
+
+    tagname = "Relationships"
+    expected_type = Relationship
+
+
+    def append(self, value):
+        super().append(value)
+        if not value.Id:
+            value.Id = f"rId{len(self)}"
+
+
+    def find(self, content_type):
+        """
+        Find relationships by content-type
+        NB. these content-types namespaced objects and different to the MIME-types
+        in the package manifest :-(
+        """
+        for r in self:
+            if r.Type == content_type:
+                yield r
+
+
+    def get(self, key):
+        for r in self:
+            if r.Id == key:
+                return r
+        raise KeyError("Unknown relationship: {0}".format(key))
+
+
+    def to_dict(self):
+        """Return a dictionary of relations keyed by id"""
+        return {r.id:r for r in self}
+
+
+    def to_tree(self):
+        tree = super().to_tree()
+        tree.set("xmlns", PKG_REL_NS)
+        return tree
+
+
+def get_rels_path(path):
+    """
+    Convert relative path to absolutes that can be loaded from a zip
+    archive.
+    The path to be passed in is that of containing object (workbook,
+    worksheet, etc.)
+    """
+    folder, obj = posixpath.split(path)
+    filename = posixpath.join(folder, '_rels', '{0}.rels'.format(obj))
+    return filename
+
+
+def get_dependents(archive, filename):
+    """
+    Normalise dependency file paths to absolute ones
+
+    Relative paths are relative to parent object
+    """
+    src = archive.read(filename)
+    node = fromstring(src)
+    try:
+        rels = RelationshipList.from_tree(node)
+    except TypeError:
+        msg = "{0} contains invalid dependency definitions".format(filename)
+        warn(msg)
+        rels = RelationshipList()
+    folder = posixpath.dirname(filename)
+    parent = posixpath.split(folder)[0]
+    for r in rels:
+        if r.TargetMode == "External":
+            continue
+        elif r.target.startswith("/"):
+            r.target = r.target[1:]
+        else:
+            pth = posixpath.join(parent, r.target)
+            r.target = posixpath.normpath(pth)
+    return rels
+
+
+def get_rel(archive, deps, id=None, cls=None):
+    """
+    Get related object based on id or rel_type
+    """
+    if not any([id, cls]):
+        raise ValueError("Either the id or the content type are required")
+    if id is not None:
+        rel = deps.get(id)
+    else:
+        try:
+            rel = next(deps.find(cls.rel_type))
+        except StopIteration: # no known dependency
+            return
+
+    path = rel.target
+    src = archive.read(path)
+    tree = fromstring(src)
+    obj = cls.from_tree(tree)
+
+    rels_path = get_rels_path(path)
+    try:
+        obj.deps = get_dependents(archive, rels_path)
+    except KeyError:
+        obj.deps = []
+
+    return obj