Strict Mode

ECMA-376 defines two conformance classes for a DOCX file, Transitional and Strict. UniOffice writes Transitional, which is what Word produces by default and what every consumer accepts. SetStrict(true) changes the class the document declares.

SetStrict is a two-value shortcut for SetConformance. Reach for SetConformance only if you need ST_ConformanceClassUnset, which is not a useful state (see Limitations).

Setting it

doc, err := document.Open("document.docx")
if err != nil {
    log.Fatal(err)
}
defer doc.Close()

doc.SetStrict(true)
if err := doc.SaveToFile("conformance_strict.docx"); err != nil {
    log.Fatal(err)
}

The setting lives on the document rather than on the save call, so one document can be written twice with different classes. That is all the example does: set it false, save, set it true, save again.

What changes in the file

One attribute value, and nothing else. Comparing the two files the example produces, every part of the package is byte-identical except word/document.xml, and the difference there is w:conformance="transitional" against w:conformance="strict" on the root element. Part names, content types and the document body are untouched.

In particular the markup keeps the Transitional namespaces (http://schemas.openxmlformats.org/wordprocessingml/2006/main and friends) in both files. UniOffice does not rewrite parts into the Strict namespaces under http://purl.oclc.org/ooxml/, and it does not inspect the document for constructs that Strict disallows. The attribute is a declaration about the file, not a conversion of it, so a validator checking the package against the Strict schema will not be satisfied by setting it. Reading works in both directions: the unmarshalers accept either namespace, so a Strict file from another producer opens normally.

Limitations

document.Open reports Transitional whatever the file said. The conformance value is captured from the freshly constructed document before the package is decoded and restored afterwards, so the value in the file is discarded. Open a Strict document, change a word, save it, and you have written a Transitional one. Call SetStrict(true) again on every round trip where the class matters.

Append can downgrade a document. If the document being appended is not Strict, the result takes that document’s class, so appending a Transitional document into a Strict one leaves you with Transitional.

SetConformance(sharedTypes.ST_ConformanceClassUnset) does not omit the attribute; it writes w:conformance="". Pre-save validation flags the attribute as mandatory and logs a warning, then the save proceeds anyway.

The setter exists only on document.Document. Spreadsheets and presentations carry the same conformance attribute in their schemas but expose no equivalent call.

Run the example

The example opens the document.docx bundled with it and writes conformance_transitional.docx and conformance_strict.docx side by side. Unzip both and diff word/document.xml to see the whole of the difference.

git clone https://github.com/unidoc/unioffice-examples.git
cd unioffice-examples/document/set-strict
go run main.go

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