FTL Viewer

The FTL Viewer renders FreeMarker Template Language content using a safe, client-side engine. It accepts FTL source and an optional JSON data model to produce a rendered output for verification and iteration. Conceptually, it executes a sandboxed mini-renderer that substitutes variables, evaluates simple conditionals and list blocks, and supports local includes from a small registry. This provides immediate feedback during development, documentation review, and teaching scenarios where a full server environment is unnecessary. Beneficiaries include backend developers, template authors, and QA engineers who need deterministic previews and quick sanity checks. Core value lies in rapid, repeatable renders with a predictable data model, reducing iteration cycles and helping identify logic errors early. Core features include a minimal FTL parser, ${var} substitution, basic <#if> and <#list> handling, and an optional includes mechanism. Outputs include the rendered text and diagnostic data to highlight syntax or data-model issues. The tool intentionally omits a full FreeMarker engine, external data fetches, or server-side processing to keep responses deterministic and privacy-preserving. Practical use cases include validating variable bindings before deployment, checking conditional branches, and comparing renders across mock data scenarios.