The ``docProps/custom.xml`` part stores user-defined name/value pairs with a typed child from the ``vt:`` namespace. This family covers one case per type python-docx can emit: lpwstr, bool, i4, r8, filetime, and (as of 2026.05.7) date.
Library verdicts: python-docx: — docxjs: —
| Feature id | docx/custom-properties-types--i4 |
|---|---|
| Format | docx |
| Category | metadata |
| Family | docx/custom-properties-types |
| Axis values | type=i4 |
| Spec | ecma-376-5-part-2 § 11.2 |
| ID / part | Predicate | XPath | python-docx | docxjs |
|---|---|---|---|---|
custom-i4-presentdocProps/custom.xml | existTestProp must carry a <vt:i4> child. | //op:property[@name='TestProp']/vt:i4 | — | — |
custom-i4-valuedocProps/custom.xml | equal = 42TestProp's <vt:i4> must carry the expected literal text. | //op:property[@name='TestProp']/vt:i4 | — | — |
No render assertions declared.
scripts/gen_custom_properties_types.py
#!/usr/bin/env python3
"""Generate ``fixtures/docx/custom-properties-types--<type>.docx`` fixtures.
Parameterised generator; drives ``features/docx/custom-properties-types.json``.
One .docx per vt: type python-docx can emit; the custom property is always
named ``TestProp``.
"""
from __future__ import annotations
import argparse
import datetime as _dt
from pathlib import Path
from docx import Document
_REPO_ROOT = Path(__file__).resolve().parent.parent
_PINNED_CREATED = _dt.datetime(2026, 1, 1, 0, 0, 0, tzinfo=_dt.timezone.utc)
_PINNED_MODIFIED = _dt.datetime(2026, 1, 2, 0, 0, 0, tzinfo=_dt.timezone.utc)
def _coerce(vt_id: str, value: str):
if vt_id == "lpwstr":
return value
if vt_id == "bool":
return value.lower() == "true"
if vt_id == "i4":
return int(value)
if vt_id == "r8":
return float(value)
if vt_id == "filetime":
# Naive datetime; python-docx treats it as UTC and serialises with Z.
return _dt.datetime.strptime(value, "%Y-%m-%dT%H:%M:%S")
if vt_id == "date":
# Calendar date with no time/zone — serialised as vt:date YYYY-MM-DD.
return _dt.datetime.strptime(value, "%Y-%m-%d").date()
raise SystemExit(f"Unknown vt type id: {vt_id!r}")
def main() -> int:
parser = argparse.ArgumentParser()
parser.add_argument("--type", dest="type_id", required=True)
parser.add_argument("--value", required=True)
parser.add_argument(
"--out",
default=str(_REPO_ROOT / "fixtures" / "docx" / "custom-properties-types.docx"),
)
args = parser.parse_args()
out_path = Path(args.out)
if not out_path.is_absolute():
out_path = _REPO_ROOT / out_path
doc = Document()
doc.core_properties.created = _PINNED_CREATED
doc.core_properties.modified = _PINNED_MODIFIED
doc.custom_properties["TestProp"] = _coerce(args.type_id, args.value)
doc.add_paragraph("Body content; custom property is the feature under test.")
out_path.parent.mkdir(parents=True, exist_ok=True)
doc.save(out_path, reproducible=True)
print(out_path)
return 0
if __name__ == "__main__":
raise SystemExit(main())
{
"$schema": "../manifest.schema.json",
"id": "docx/custom-properties-types--i4",
"kind": "literal",
"title": "Custom document properties: one case per vt: type",
"format": "docx",
"category": "metadata",
"summary": "The ``docProps/custom.xml`` part stores user-defined name/value pairs with a typed child from the ``vt:`` namespace. This family covers one case per type python-docx can emit: lpwstr, bool, i4, r8, filetime, and (as of 2026.05.7) date.",
"spec": {
"source": "ecma-376-5-part-2",
"clause": "11.2",
"notes": "ECMA-376 Part 2 / ISO 29500-2 section 11.2 defines the OPC custom-properties part. Each property must have a unique name, a fmtid, a pid >= 2, and exactly one typed child from the ``vt:`` (officeDocument/2006/docPropsVTypes) namespace. Supported authoring-side types in python-docx: ``str`` -> ``vt:lpwstr``, ``int`` -> ``vt:i4``, ``float`` -> ``vt:r8``, ``bool`` -> ``vt:bool``, ``datetime.datetime`` -> ``vt:filetime``, ``datetime.date`` -> ``vt:date`` (ECMA-376 Part 1 §22.4.2.7 — a calendar date with no time or zone, added in python-docx 2026.05.7 / Wave 8 W8-E)."
},
"fixtures": {
"machine": "docx/custom-properties-types--i4"
},
"generator": {
"python": "scripts/gen_custom_properties_types.py",
"arg_template": "--type {type.id} --value \"{type.value}\" --out fixtures/docx/custom-properties-types--{type.id}.docx"
},
"_expansion": {
"parent_id": "docx/custom-properties-types",
"bindings": {
"type": "i4"
}
},
"assertions": [
{
"id": "custom-i4-present",
"part": "docProps/custom.xml",
"namespaces": {
"op": "http://schemas.openxmlformats.org/officeDocument/2006/custom-properties",
"vt": "http://schemas.openxmlformats.org/officeDocument/2006/docPropsVTypes"
},
"xpath": "//op:property[@name='TestProp']/vt:i4",
"must": "exist",
"description": "TestProp must carry a <vt:i4> child."
},
{
"id": "custom-i4-value",
"part": "docProps/custom.xml",
"namespaces": {
"op": "http://schemas.openxmlformats.org/officeDocument/2006/custom-properties",
"vt": "http://schemas.openxmlformats.org/officeDocument/2006/docPropsVTypes"
},
"xpath": "//op:property[@name='TestProp']/vt:i4",
"must": "equal",
"value": "42",
"description": "TestProp's <vt:i4> must carry the expected literal text."
}
]
}
No rendered reference is available for this case.