ValidatePdfUa method

Checks the currently open PDF for PDF/UA-1 compliance markers and returns a structured result with the detected conformance level plus the issues it found

ValidatePdfUa walks the open document looking for the PDF/UA-1 file-format markers defined by ISO 14289-1:2014:

• An XMP metadata stream with pdfuaid:part = 1 and the matching pdfaExtension:schemas description (§5).
• The mandatory dc:title entry inside the XMP packet (§7.1).
• A StructTreeRoot in the catalogue or somewhere in the file (§7.1) — required so the document can carry tagging at all.
• Catalogue /MarkInfo << /Marked true /Suspects false >> (§7.1).
• Catalogue /ViewerPreferences << /DisplayDocTitle true >> (§7.1).
• Catalogue /Lang with a BCP 47 language tag (§7.2).
• Trailer /ID array and the absence of encryption.
• xmp:CreateDate / xmp:ModifyDate (recommended for Info/XMP parity).

The result is a TPdfUaValidationResult record:

• Conformance — the detected level: puc1 (PDF/UA-1 identifier found), pucNone (no PDF/UA marker), or pucUnknown (parse failed).
• Issues — a TPdfUaValidationIssues set containing zero or more values: pvuaiMissingXmpMetadata, pvuaiMissingPdfUaIdentifier, pvuaiMissingExtensionSchema, pvuaiMissingDcTitle, pvuaiMissingStructTreeRoot, pvuaiMissingMarkInfo, pvuaiSuspectsTrue, pvuaiMissingDisplayDocTitle, pvuaiMissingLang, pvuaiEncryptionPresent, pvuaiMissingTrailerId, pvuaiMissingXmpDates, pvuaiFontNotEmbedded, pvuaiFontMissingToUnicode, pvuaiMissingTabsOrder, pvuaiFigureMissingAlt, pvuaiFormulaMissingAlt, pvuaiNoteMissingId
• IsCompliant — returns True when Conformance is a real PDF/UA level and Issues is empty

ValidatePdfUa is a read-only inspection — it does not modify the document and is safe to call repeatedly. Use it before handing a PDF off to an archive system or accessibility checker to surface non-compliance to the operator. For the common "is this PDF/UA-1?" check that does not need the issue list, prefer the lighter-weight PdfUaConformance property

• ValidatePdfUa covers the file-format markers, a few byte-checkable content heuristics (font embedding, ToUnicode CMaps, page /Tabs /S tab order), and three high-confidence structure-tree checks (Figure missing Alt/ActualText, Formula missing Alt, Note missing a unique ID). It does not verify the remaining content-level PDF/UA rules — heading nesting, Form widget tagging, table /TH /Scope attributes, RoleMap correctness, logical reading order, and so on. For a full validator pair this method with an external tool such as PAC 2024 or axesPDF
• Calling ValidatePdfUa on an inactive document returns a record with Conformance = pucUnknown and an empty Issues set
• The validator only flags pvuaiSuspectsTrue when an explicit /Suspects true appears in /MarkInfo. Documents that do not have the /Suspects key at all are considered compliant on that point (the spec only forbids true)
• SaveAsPdfUa enforces the ISO 14289-1 7.1 mandatory /ViewerPreferences /DisplayDocTitle true and /MarkInfo /Marked true /Suspects false entries even when the source provides those dictionaries incompletely or as an indirect reference (N 0 R); existing keys are preserved and the dictionary is normalised to a direct dictionary in the rewritten catalog

PdfUaConformance, SaveAsPdfUa, SaveAsPdfUaToStream, IsTagged, ValidatePdfA