PPTX Slide

1"""Pick the slide-XML schema errors PowerPoint refuses the file over.
2
3A denylist over lxml's messages, so an unrecognised error class is a miss rather
4than a false alarm.
5"""
6
7
8from __future__ import annotations
9
10import re
11
12SLIDE_PART_RE = re.compile(
13    r"ppt/(slides|slideLayouts|slideMasters|notesSlides|notesMasters|handoutMasters)"
14    r"/[^/]+\.xml"
15)
16
17FATAL_SLIDE_ERRORS: tuple[tuple[re.Pattern[str], str], ...] = (
18    (
19        re.compile(r"\}tableStyleId': This element is not expected"),
20        "two <a:tableStyleId> in one <a:tblPr> (the schema allows one)",
21    ),
22    (
23        re.compile(r"\}srgbClr', attribute 'val'"),
24        "a colour that is not six hex digits",
25    ),
26    (
27        re.compile(r"\}txBody': Missing child element"),
28        "a <p:txBody> with no children",
29    ),
30    (
31        re.compile(r"\}miter', attribute 'lim'"),
32        'a line join with lim="NaN"',
33    ),
34    (
35        re.compile(r"\}uLnTx': This element is not expected"),
36        "<a:uLnTx> in a position the schema forbids",
37    ),
38    (
39        re.compile(r"\}overrideClrMapping': This element is not expected"),
40        "<p:overrideClrMapping> in a position the schema forbids",
41    ),
42    (
43        re.compile(r"\}nvGrpSpPr': Missing child element"),
44        "a <p:nvGrpSpPr> with no children",
45    ),
46)
47
48
49def is_schema_verdict(error: str) -> bool:
50    return error.startswith("Element ")
51
52
53def fatal_slide_errors(errors: set[str]) -> list[str]:
54    out = []
55    for error in sorted(errors):
56        for pattern, meaning in FATAL_SLIDE_ERRORS:
57            if pattern.search(error):
58                out.append(f"{meaning}: {error}")
59                break
60    return out