"""Provides the PackURI value type and known pack-URI strings such as PACKAGE_URI."""
from __future__ import annotations
import posixpath
import re
class PackURI(str):
"""Proxy for a pack URI (partname).
Provides utility properties the baseURI and the filename slice. Behaves as |str| otherwise.
"""
_filename_re = re.compile("([a-zA-Z]+)([0-9][0-9]*)?")
def __new__(cls, pack_uri_str: str):
if not pack_uri_str[0] == "/":
raise ValueError(f"PackURI must begin with slash, got {repr(pack_uri_str)}")
return str.__new__(cls, pack_uri_str)
@staticmethod
def from_rel_ref(baseURI: str, relative_ref: str) -> PackURI:
"""Construct an absolute pack URI formed by translating `relative_ref` onto `baseURI`."""
joined_uri = posixpath.join(baseURI, relative_ref)
abs_uri = posixpath.abspath(joined_uri)
return PackURI(abs_uri)
@property
def baseURI(self) -> str:
"""The base URI of this pack URI; the directory portion, roughly speaking.
E.g. `"/ppt/slides"` for `"/ppt/slides/slide1.xml"`.
For the package pseudo-partname "/", the baseURI is "/".
"""
return posixpath.split(self)[0]
@property
def ext(self) -> str:
"""The extension portion of this pack URI.
E.g. `"xml"` for `"/ppt/slides/slide1.xml"`. Note the leading period is not included.
"""
# -- raw_ext is either empty string or starts with period, e.g. ".xml" --
raw_ext = posixpath.splitext(self)[1]
return raw_ext[1:] if raw_ext.startswith(".") else raw_ext
@property
def filename(self) -> str:
"""The "filename" portion of this pack URI.
E.g. `"slide1.xml"` for `"/ppt/slides/slide1.xml"`.
For the package pseudo-partname "/", `filename` is ''.
"""
return posixpath.split(self)[1]
@property
def idx(self) -> int | None:
"""Optional int partname index.
Value is an integer for an "array" partname or None for singleton partname, e.g. `21` for
`"/ppt/slides/slide21.xml"` and |None| for `"/ppt/presentation.xml"`.
"""
filename = self.filename
if not filename:
return None
name_part = posixpath.splitext(filename)[0] # filename w/ext removed
match = self._filename_re.match(name_part)
if match is None:
return None
if match.group(2):
return int(match.group(2))
return None
@property
def membername(self) -> str:
"""The pack URI with the leading slash stripped off.
This is the form used as the Zip file membername for the package item. Returns "" for the
package pseudo-partname "/".
"""
return self[1:]
def relative_ref(self, baseURI: str) -> str:
"""Return string containing relative reference to package item from `baseURI`.
E.g. PackURI("/ppt/slideLayouts/slideLayout1.xml") would return
"../slideLayouts/slideLayout1.xml" for baseURI "/ppt/slides".
"""
# workaround for posixpath bug in 2.6, doesn't generate correct
# relative path when `start` (second) parameter is root ("/")
return self[1:] if baseURI == "/" else posixpath.relpath(self, baseURI)
@property
def rels_uri(self) -> PackURI:
"""The pack URI of the .rels part corresponding to the current pack URI.
Only produces sensible output if the pack URI is a partname or the package pseudo-partname
"/".
"""
rels_filename = "%s.rels" % self.filename
rels_uri_str = posixpath.join(self.baseURI, "_rels", rels_filename)
return PackURI(rels_uri_str)
PACKAGE_URI = PackURI("/")
CONTENT_TYPES_URI = PackURI("/[Content_Types].xml")