Validate PDF/A-4 Standard

Validation tells you whether a file already satisfies PDF/A-4, without changing it. Because part 4 has three profiles rather than conformance levels, checking a document usually means trying each in turn and seeing which it passes.

Doing it

Validation needs a compliance reader, not an ordinary one:

detailedReader, err := model.NewCompliancePdfReader(inputFile)
if err != nil {
    return err
}

standards := []model.StandardImplementer{
    pdfa.NewProfile4(nil),
    pdfa.NewProfile4E(nil),
    pdfa.NewProfile4F(nil),
}

for _, standard := range standards {
    if err = standard.ValidateStandard(detailedReader); err != nil {
        fmt.Printf("%s: %v\n", standard.StandardName(), err)
        continue
    }
    fmt.Printf("%s: passed\n", standard.StandardName())
}

NewCompliancePdfReader keeps the extra structural detail the verifiers need, which a normal PdfReader discards. Passing an ordinary reader is not an option; the signature requires the compliance type.

StandardName() returns PDF/A-4, PDF/A-4e or PDF/A-4f, so it is a convenient label for the result line. One reader can be checked against every profile in turn, as above.

Reading the result

ValidateStandard returns nil when the document conforms, and an error describing the violated rules otherwise. It is a report, not a hard failure: a document failing PDF/A-4 may still pass PDF/A-4f if the only problem was an embedded file, which is exactly why the example tries all three.

Limitations

This is UniPDF’s own verifier, and it is not a substitute for an independent one. Check ValidateStandard’s godoc for the known limitations of the current implementation, and run veraPDF as well before publishing a conformance claim.

Validation is separate from the identification metadata. A file can carry a pdfaid claim in its XMP and still fail, and vice versa; see get PDF/A identification metadata for reading the claim rather than testing the reality.

Run the example

pdfa4_validate_standard.go opens the input with a compliance reader, tries all three part 4 profiles, and prints the outcome for each along with the elapsed time.

git clone https://github.com/unidoc/unipdf-examples.git
cd unipdf-examples/pdfa
go run pdfa4_validate_standard.go <input.pdf>

If this is your first time using UniPDF, follow the getting started guide to create an API key and set up your development environment.

Sample output