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wordcraft/docs/odf-interpretation.md
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Claude 48ff99e52c M5 #19: LibreOffice reads WordCraft's ODT settings; paragraph spacing setting
Found by comparing WordCraft's own documents in LibreOffice and
bisecting settings.xml (observed only, black-box):

- The settings set's name, ooo:configuration-settings, is a qualified
  name: without xmlns:ooo declared LibreOffice ignored every setting
  WordCraft wrote (its Word layout rules, tab measuring).
- A set LibreOffice reads must be complete: a setting missing from it
  gets its old pre-OpenOffice value, which changes the layout. WordCraft
  now writes LibreOffice's current layout defaults (as a new LibreOffice
  document has them), overlaid with Word's layout rules for documents
  WordCraft lays out as Word does (not for ones opened from ODF), and
  its own choices.
- How the space between paragraphs adds up follows a file's
  AddParaTableSpacing (false: the larger, as Word); unstated, the ODF
  profile's new sumParagraphSpacing (WordCraft: the larger, LibreOffice:
  the sum). WordCraft writes it as it lays the document out.

WordCraft-origin documents in LibreOffice: 142k -> 80k differing pixels
over 42 documents; the LibreOffice corpus: no regressions, 40k -> 39.6k.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GBVQLyDnrG8Tn1yDQcUabC
2026-11-03 00:49:05 +00:00

9.6 KiB
Raw Blame History

How WordCraft interprets OpenDocument files

Last reviewed: 2026-11-02 · Last updated: 2026-11-03 · Change: major (new: the ODF interpretation profile and the list of every case)

OpenDocument (ODF 1.3, OASIS) leaves some of a document's look to the application. Part 3 §16.2 says that when no style sets a property and the standard gives no default, "an implementation-dependent value is used". So a file can look different in WordCraft, LibreOffice, Google Docs and ONLYOFFICE without anyone being wrong. This page lists every such case WordCraft knows of, so none gets lost.

The rule

  1. What the standard defines is law. WordCraft follows it whatever the settings say. That includes fo: properties, which the standard defines by referring to XSL 1.0, for their meaning. Whether such a reference also brings XSL's initial value as the default the standard doesn't say; where an application's choice differs from XSL's (page margins), the case is a setting, with XSL's value as WordCraft's.
  2. What the standard leaves open is a setting. Each such case is one value of the ODF interpretation profile (OdfProfile, crates/doc/src/odf_profile.rs):
    • WordCraft, the default: what WordCraft does for its own and Word documents.
    • LibreOffice: what LibreOffice (and Collabora, which shares its engine) does. Measured black-box in LibreOffice 24 where it isn't documented.
    • Custom: the user's own value for each case. It starts from the preset that was in use.
  3. A value the file states is the file's. A preset never replaces it: the profile only fills in what the file (its styles, defaults and settings.xml) leaves unsaid. Three cases are not missing values but stated ones whose meaning the standard leaves open: how a header's stated height and spacing combine, what a stated width of 0 draws at, and a frame position stated against something the standard doesn't define for its anchor. They are marked (meaning) below. formats::odt::tests_more::profile checks that stated values survive every preset.
  4. The profile applies to ODF files (.odt, .ott, .fodt) as they are opened. A document keeps what it was opened with. Changing the setting affects the next file opened.

Where to set it:

Interface How
App File › Options › Advanced › OpenDocument files
Command file.options {"odf": {"preset": "libreoffice"}}, or one case's value: {"odf": {"columnGap": 18}} (this makes the profile custom)
MCP the same command
CLI WORDCRAFT_ODF=wordcraft|libreoffice

Cases the standard leaves open (the profile)

Case Standard Setting (file.options odf.*) WordCraft LibreOffice
Page margins a page layout doesn't state §20.206–20.209 refer to XSL §7.10 (initial value 0); whether that default comes with the reference is not said pageMargin 0 (XSL's initial value) 2 cm (its own files always state theirs; some of its templates don't)
Height of a header or footer whose style states none §20.212.2 fo:min-height: no default headerMinHeight 0 (as tall as its text) 0.5 cm
(meaning) Whether a header's stated minimum height includes its stated spacing from the body §20.212.2, §20.207: not said headerHeightIncludesSpacing no: spacing comes after the height yes
A header taller than its height with style:dynamic-spacing unstated §20.264: no default dynamicSpacing off: the spacing is kept (on, with no height stated, would always drop the spacing the file states) off
Where paragraph tab stops are measured from when settings.xml doesn't say §19.512.3 style:position doesn't say; §19.861 covers only indexes tabsFromIndent the margin (as Word; ONLYOFFICE's files mean this too) the paragraph's indent (its TabsRelativeToIndent default)
Gap between columns when style:columns states none §19.233 fo:column-gap: no default (and explicitly not XSL's) columnGap 0.5 in (Word's) 0
A drawing shape's fill colour when no style gives one §20.119 draw:fill-color: no default shapeFill #156082 (WordCraft's shape blue) #729FCF
A drawing shape's line colour when no style gives one §20.408 svg:stroke-color: no default shapeLine #0E405A #3465A4
A shape's line width when unstated, and (meaning) what a stated width of 0 (a hairline) draws at §20.410 svg:stroke-width: no default hairline 0.25 pt 0.5 pt
(meaning) A page-anchored frame positioned against a paragraph or character §20.299, §20.398 Table 23: combination not defined pageFrameParagraphIsPage the page's text area the page's edge
(meaning) An in-line frame positioned against a paragraph or page §20.398 Table 23: combination not defined inlineInvalidRelationIsBaseline stands on the baseline positioned against the baseline (raised by its offset)
Height of a line holding only in-line pictures no line-height algorithm in the standard pictureLinesFitPictures as tall as its text would be too as tall as the pictures
How the space between two paragraphs adds up when the document doesn't say not defined (fo:margin-top/-bottom refer to XSL's margins; whether XSL's space resolution, which keeps the larger, comes with them is not said); LibreOffice's AddParaTableSpacing setting says when present (false: the larger) sumParagraphSpacing the larger of the two (as Word) their sum
(meaning) Whether a columned section's columns end balanced when nothing follows it on the page, and when it doesn't say §20.428 text:dont-balance-text-columns: no default, and its value descriptions contradict its name (WordCraft reads the name; so does LibreOffice) balanceSectionColumns as Word: only when text follows on the same page balanced

Law: what the standard defines and WordCraft follows whatever the profile

Case Rule Note
Paragraph padding on a side without a border fo:padding (§20.217) is XSL's box model: padding takes room whether or not there is a border Word ignores padding without a border. ODF documents don't.
A frame's style:run-through when unstated §20.351: foreground
style:dynamic-spacing="true"/"false" when stated §20.264 WordCraft writes false when a header or footer has spacing, so every reader keeps it.

Open in the standard, and the same in every preset

These are documented so they aren't mistaken for law:

Case Standard What WordCraft does
Paper size when no page layout states one not defined the region's paper (Letter in the US, A4 elsewhere), as for new documents
style:wrap unstated on a frame §20.400: no default text wraps on both sides (LibreOffice too)
A drawing shape's draw:fill / draw:stroke unstated §20.118, §20.167: no default solid (LibreOffice too); a text frame's are none; the colours are in the profile
A document's default font and size when no default style gives them not defined WordCraft's defaults

How WordCraft writes ODF

WordCraft writes files that every reader takes the same way. It states what the standard leaves open instead of relying on any application's default:

  • header and footer heights, with style:dynamic-spacing="false" when there is spacing;
  • a frame's placement as an explicit position against the page or paragraph;
  • in-line pictures standing on the baseline;
  • tab stops measured as settings.xml says.

Not implemented

LibreOffice refreshes fixed dates and fills in the user's sender fields when it opens a template (.ott) to make a new document. That is application behaviour, not something the file defines. WordCraft opens a template as it is.

Other applications

Google Docs and ONLYOFFICE files were checked for cases they rely on (November 2026, nine files from public bug reports and ONLYOFFICE's converter test snapshots):

  • Google Docs exports through a LibreOffice build (its generator reads LibreOfficeDev/6.0). It states its page size and margins, writes TabsRelativeToIndent=false, and its default graphic style states LibreOffice's colours. Its headers are empty styles with no content. Nothing in these files depends on the profile beyond what the LibreOffice preset covers.
  • ONLYOFFICE states page size and margins only. It has no header styles and no default graphic style. It writes tab stops with no TabsRelativeToIndent and means "from the margin" (its documents come from Word's model), which is WordCraft's default.

So neither needs a preset of its own yet. If later files show cases where they differ, a preset is one more OdfPreset with its values, and the cases above stay the same.

Revision history

Date Change
2026-11-03 Paragraph spacing (sumParagraphSpacing); a file's AddParaTableSpacing is followed, and WordCraft writes it. WordCraft's settings.xml now declares the ooo namespace, without which LibreOffice ignored all of its settings.
2026-11-03 Section column balancing (balanceSectionColumns); §20.428's contradiction recorded. WordCraft writes text:dont-balance-text-columns on every columned section.
2026-11-02 Unstated page margins are a setting (pageMargin: WordCraft 0, XSL's initial value; LibreOffice 2 cm), not law: the standard refers to XSL's margins without saying whether XSL's default comes too.
2026-11-02 First version: the profile, the open cases, law cases, writer choices, Google Docs and ONLYOFFICE findings. Stated values are never replaced by a preset; the cases about the meaning of stated values are marked.