TXTextControl.PDF.Validation 34.1.0

TXTextControl.PDF.Validation

TXTextControl.PDF.Validation is a .NET library for validating PDF/UA accessibility characteristics in PDF documents.

The library returns a structured validation report with PDF/UA findings, extracted document information, and separate document diagnostics for signatures and encryption.

Requirements

• .NET 10
• Read access to the PDF file or PDF bytes to validate

Installation

Reference the package or project from your application:

<PackageReference Include="TXTextControl.PDF.Validation" Version="34.1.0" />

Quick Start

using TXTextControl.PDF.Validation;
using TXTextControl.PDF.Validation.Model;

Report report = PdfUaValidator.Validate("document.pdf");

Console.WriteLine(report.Status);

foreach (Finding finding in report.Findings)
{
    Console.WriteLine($"{finding.Severity} {finding.RuleId}: {finding.Message}");
}

Validate PDF Bytes

byte[] pdf = File.ReadAllBytes("document.pdf");
Report report = PdfUaValidator.Validate(pdf);

JSON Output

Report report = PdfUaValidator.Validate("document.pdf");
string json = PdfUaValidator.ToJson(report, indented: true);

Console.WriteLine(json);

The JSON output includes:

• status
• isPass
• findings
• tableSummaries
• links
• figures
• forms
• standards
• diagnostics.signatures
• diagnostics.encryption

Validation Status

Every report has a top-level Status value:

Report.IsPass is kept as a convenience property. It returns true for Passed and CompletedWithWarnings, and false for Failed and Blocked.

Report Model

The main report type is TXTextControl.PDF.Validation.Model.Report.

Important properties:

Findings

Each finding contains:

Only failed Error findings make the report status Failed. Failed Warning findings make the status CompletedWithWarnings unless an error is also present.

What Is Checked

The validator checks the following areas:

• PDF syntax basics, including header and cross-reference presence
• PDF/UA metadata and conformance declarations
• document title and XMP metadata
• natural language declarations
• tagged PDF markers
• structure tree presence and selected structure consistency checks
• role mapping
• fonts, embedded font references, and ToUnicode maps
• alternate descriptions for figures
• links and link descriptions
• form fields and tooltip coverage
• tables, summaries, and selected header relationships
• embedded files and file specification metadata
• document settings such as page tabs and display document title
• optional content
• XFA detection
• security/encryption detection
• navigation structures
• annotations
• actions and XObjects

Signed PDFs

Signed PDFs can be validated normally.

Signature validation is reported separately under:

report.Diagnostics.Signatures

Signature diagnostics include:

• number of signatures
• signature byte integrity
• whether each signature covers the whole document
• signer subject
• signing time
• subfilter
• ByteRange values
• /Contents gap range
• verification failure details, if any

Signature diagnostics do not affect PDF/UA pass/fail status. A broken signature is a document diagnostic, not a PDF/UA validation error.

Encrypted PDFs

Encrypted or password-protected PDFs are not decrypted by this library.

If an encrypted PDF is detected:

• report.Status is Blocked
• report.IsPass is false
• report.Diagnostics.Encryption.IsEncrypted is true
• a failed UA-SECURITY-ENCRYPTED finding is added
• PDF/UA validation stops before content, tags, forms, links, and alternate text are inspected

This behavior is intentional. The validator does not include a PDF decryption engine or external PDF processing dependency.

Console Tester

The repository includes pdfuatester, a small console application for manual validation.

Run the default signed sample:

dotnet run --project pdfuatester -c Release

The default sample is:

documents/result-7.pdf

It runs the full PDF/UA validation and prints signature diagnostics.

Validate a specific file:

dotnet run --project pdfuatester -c Release -- path\to\document.pdf

Validate all bundled samples:

dotnet run --project pdfuatester -c Release -- --all

Emit JSON:

dotnet run --project pdfuatester -c Release -- path\to\document.pdf --json

Scope and Limitations

The validator is designed to provide structured PDF/UA validation coverage without embedding a full general-purpose PDF processor.

Some checks are precise model-based validations. Others are conservative review signals where complete validation requires deeper PDF interpretation, for example:

• exact /ParentTree to /OBJR annotation linkage
• link annotation nesting under /Link
• widget annotation nesting under /Form
• Form XObject structure incorporation
• full MCID-to-structure-parent validation for every marked-content sequence
• semantic review of outlines, page labels, and action behavior

These areas may be reported as informational review findings instead of hard failures when the validator cannot prove an error from the available model.

API Reference

public static class PdfUaValidator
{
    public static Report Validate(string pdfPath);
    public static Report Validate(byte[] pdfData);
    public static string ToJson(Report report, bool indented = false);
}

Namespace:

TXTextControl.PDF.Validation

Model namespace:

TXTextControl.PDF.Validation.Model