losLab PDF Library ofrece a los equipos de Delphi y C++Builder un motor PDF con código fuente disponible para flujos de escritorio, servidor, DLL, ActiveX y Dylib, con comprobaciones PDF/A y PDF/UA integradas, soporte de firma PAdES y opciones de renderizado sin enviar documentos a un servicio PDF externo.
Este artículo está dirigido a developers delivering archive-ready and accessibility-aware PDFs from Delphi systems. Presenta PDF/A and PDF/UA preflight como una práctica de ingeniería documental para producción, no como una llamada aislada al componente.
El riesgo principal es que PDF/A and PDF/UA failures usually reflect document design decisions, so late preflight without ownership produces lists of issues nobody can fix. Por eso el flujo necesita contrato escrito, diagnósticos observables y archivos de regresión reales.
Decisiones de arquitectura
Connect preflight findings to template ownership. target PDF/A profile, PDF/UA expectations, and accepted validator set / font, metadata, color, annotation, form, and attachment policies
- target PDF/A profile, PDF/UA expectations, and accepted validator set
- font, metadata, color, annotation, form, and attachment policies
- tag structure, heading order, table markup, alternate text, and artifacts
- issue ownership and release-gate severity mapping
Flujo de implementación
Treat diagnostics as product requirements. The order below keeps the workflow reviewable for Delphi and C++Builder teams.
- configure document generation around the target profiles before output
- run structured preflight and normalize findings by owner and severity
- route template issues to template maintainers and data issues to application owners
- rerun validation after each fix rather than relying on visual inspection
- ship the report with the document package when customers require evidence
Evidencia de validación
Preflight evidence for archive and accessibility workflows. Keep these fields with the output or support record.
- profile, validator version, issue code, severity, page, object, and owner
- font embedding, output intent, metadata, and attachment findings
- tagging diagnostics such as heading order, table structure, artifacts, and alternate text
- release decision, waivers, and final pass or fail report
Archive and accessibility profiles ask different questions
PDF/A focuses on durable reproduction while PDF/UA focuses on semantic access. A production workflow should keep both validation profiles visible and assign findings to generation code, templates, or content owners.
Review questions before release
Before this reaches production, the team should be able to answer these questions without reading source code.
- Who owns target PDF/A profile, PDF/UA expectations, and accepted validator set?
- What evidence proves profile, validator version, issue code, severity, page, object, and owner?
- What happens when an archive-valid file can still have poor reading order?
- Which regression file covers ship the report with the document package when customers require evidence?
Engineering review notes for PDF/A and PDF/UA preflight
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 PDF/A profile, PDF/UA expectations, and accepted validator set. Implementation pressure point: run structured preflight and normalize findings by owner and severity. Acceptance evidence: tagging diagnostics such as heading order, table structure, artifacts, and alternate text. Regression trigger: third-party inserted pages can break profile assumptions late in assembly
- Decision: font, metadata, color, annotation, form, and attachment policies. Implementation pressure point: route template issues to template maintainers and data issues to application owners. Acceptance evidence: release decision, waivers, and final pass or fail report. Regression trigger: an archive-valid file can still have poor reading order
- Decision: tag structure, heading order, table markup, alternate text, and artifacts. Implementation pressure point: rerun validation after each fix rather than relying on visual inspection. Acceptance evidence: profile, validator version, issue code, severity, page, object, and owner. Regression trigger: decorative content should be marked as artifacts instead of hidden visually only
- Decision: issue ownership and release-gate severity mapping. Implementation pressure point: ship the report with the document package when customers require evidence. Acceptance evidence: font embedding, output intent, metadata, and attachment findings. Regression trigger: forms and annotations can conflict with archive goals depending on profile
Casos límite
- an archive-valid file can still have poor reading order
- decorative content should be marked as artifacts instead of hidden visually only
- forms and annotations can conflict with archive goals depending on profile
- third-party inserted pages can break profile assumptions late in assembly
Delphi / C++Builder notes
PDFlibPas 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/UA, CreatePreflightReportEx, accessibility, tag structure, validator.
Ejemplo de código Delphi
El siguiente esquema en Delphi muestra un límite de servicio práctico para este tema. Mantén las comprobaciones de política, el registro y la validación fuera del bloque estrecho que llama al producto para que el flujo sea comprobable.
procedure RunStandardsPreflight(const InputFile, ReportFile: string; const Profile: string);
var
Pdf: TPDFlib;
begin
Pdf := TPDFlib.Create;
try
Pdf.LoadFromFile(InputFile, '');
TFile.WriteAllText(ReportFile, BuildStandardsReport(Pdf, Profile), TEncoding.UTF8);
FailOnBlockingStandardsIssues(ReportFile);
finally
Pdf.Free;
end;
end;Lista de salida a producción
- 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