技術記事

HotPDF Component: Delphi での PDF/A, PDF/X, and PDF/UA validation

HotPDF は Delphi/C++Builder アプリケーション向けのネイティブ VCL PDF ライブラリです。外部 PDF ランタイムを配置せずに、PDF 作成、編集、フォーム、注釈、暗号化、デジタル署名、Unicode フォント、標準対応出力、プリフライトレポートを扱えます。

この記事は teams that deliver archival, print, or accessibility-sensitive PDF output from Delphi applications 向けです。PDF/A, PDF/X, and PDF/UA validation を単なるコンポーネント呼び出しではなく、本番向けのドキュメントエンジニアリングとして扱います。

実務上のリスクは a document can pass a visual review while missing fonts, output intents, tagged structure, metadata, or accessibility semantics required by the target standard です。そのため、明確な契約、観測可能な診断、実際の顧客ファイルに近い回帰サンプルが必要です。

アーキテクチャ上の判断

Select the standard before generating pages. target profile and conformance level for each output channel / font embedding, color profile, metadata, and transparency policy

  • target profile and conformance level for each output channel
  • font embedding, color profile, metadata, and transparency policy
  • tagging, reading order, alternate text, and artifact treatment
  • whether validation warnings block release or require documented waivers

実装フロー

Use preflight findings as engineering requirements. The order below keeps the workflow reviewable for Delphi and C++Builder teams.

  1. select the compliance profile before creating the first page object
  2. configure fonts, images, color spaces, metadata, and tagging around that profile
  3. run preflight after generation and parse findings into actionable categories
  4. fix the document source instead of patching the PDF when the issue is template-owned
  5. save the validation report with the output package or support evidence

検証エビデンス

Validation artifacts for release and support. Keep these fields with the output or support record.

  • profile name, validator version, pass or fail status, and issue severity counts
  • font, color, metadata, tag-structure, and annotation findings
  • waiver owner and business reason for every accepted warning
  • sample output opened in the target archive, print, or accessibility workflow

Compliance choices affect layout and content

PDF/A, PDF/X, and PDF/UA optimize for different guarantees. A single document may not satisfy every profile without tradeoffs in color management, interactivity, transparency, tagging, or embedded content.

Operational metrics to watch

The first release should expose enough metrics to prove the workflow is healthy under real files, not only under curated samples.

  • count and rate for profile name, validator version, pass or fail status, and issue severity counts
  • warning trend for interactive forms and JavaScript may conflict with archival profiles
  • latency of the stage that must select the compliance profile before creating the first page object
  • profile usage for target profile and conformance level for each output channel

Engineering review notes for PDF/A, PDF/X, and PDF/UA validation

Use these review notes to make sure the feature has moved beyond a demo and can be defended during release, support, and customer escalation.

  • Decision: target profile and conformance level for each output channel. Implementation pressure point: configure fonts, images, color spaces, metadata, and tagging around that profile. Acceptance evidence: waiver owner and business reason for every accepted warning. Regression trigger: third-party template assets often introduce fonts or transparency outside policy
  • Decision: font embedding, color profile, metadata, and transparency policy. Implementation pressure point: run preflight after generation and parse findings into actionable categories. Acceptance evidence: sample output opened in the target archive, print, or accessibility workflow. Regression trigger: interactive forms and JavaScript may conflict with archival profiles

境界ケース

  • interactive forms and JavaScript may conflict with archival profiles
  • print-ready color requirements do not automatically satisfy accessibility needs
  • tagged PDF repair late in the process is expensive and error-prone
  • third-party template assets often introduce fonts or transparency outside policy

Delphi / C++Builder notes

HotPDF Component should sit behind a small service boundary that receives files, streams, profiles, and credentials, then returns output paths, warnings, metrics, and validation status. Important terms include PDF/A, PDF/X, PDF/UA, preflight, output intent, tagged PDF.

Delphi コード例

次の Delphi スケッチは、このテーマに対する実用的なサービス境界を示します。ポリシー確認、ログ記録、検証を製品呼び出しの狭い部分の外側に置くと、ワークフローをテストしやすくなります。

procedure ExportStandardsAwarePdf(const OutputFile: string; const ProfileName: string);
var
  Pdf: THotPDF;
  Report: string;
begin
  Pdf := THotPDF.Create(nil);
  try
    Pdf.FileName := OutputFile;
    ConfigureStandardsProfile(Pdf, ProfileName);
    Pdf.BeginDoc;
    WriteTaggedContent(Pdf);
    Pdf.EndDoc;
    Report := Pdf.CreatePreflightReport(OutputFile);
    FailBuildOnPreflightErrors(Report);
  finally
    Pdf.Free;
  end;
end;

本番チェックリスト

  • Run the workflow on an empty file, a normal customer file, and a worst-case file
  • Open the generated PDF with the target viewer, validator, printer, or downstream application
  • Log product version, profile version, input hash, output path, elapsed time, and warning count
  • Keep passwords, certificates, temporary files, and customer data under explicit retention rules
  • Add regression documents when a customer file exposes a new edge case

Product documentation

HotPDF Component