Formidable — The Dynamic Form & Template Designer

Formidable is a desktop app for designing YAML-based form templates, filling them out, and rendering the result through a Handlebars + Markdown pipeline. It's the Wails 3 + Go + Vue 3 successor to the original Electron build — same templates, same field types, same "auditability by design" stance, but a smaller native binary, a proper Go backend, and a real REST API.

💠 Dedicated to Elly — who lived with strength, humor and clarity. "Sleep, don't weep — My sweet love" — from album "9" by Damien Rice

🌌 And to Aaron Swartz — who refused to back down when it mattered. "We are all made of stardust, and we are all made of stories." — Aaron Swartz

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Status

Alpha. Working today:

• Template designer + form editor (17 stored field types, full Handlebars rendering, live slideout preview)
• Per-profile context folders, profile switching, VFS resolution
• Internal HTTP server with two surfaces:
  • Wiki — /, /template/{stem}, /template/{stem}/form/{datafile}
  • REST API — full CRUD on collection-enabled templates + Swagger UI at /api/docs/
• SQLite-backed per-profile index for sub-millisecond list/search
• Append-only system-level journal recording every FS mutation (groundwork for git/gigot sync)

WIP:

• Frontend journal viewer + git/gigot sync triggers (backend journal records; no UI yet)
• Plugin system (placeholder workspace; not ported)
• Per-template ACL on the API write surface
• Per-user data dir resolver for installed builds (XDG/AppData paths)

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Architecture

Composition root in internal/app/app.go wires every module once at boot.

Backend (internal/modules/)

Module	Role
system	Atomic FS primitives (temp+fsync+rename); journals every mutation
sfr	Sanitize-Filename-Read wrapper for safe content r/w
config	User config, boot profile, virtual file structure resolution
journal	Append-only change log; emits journal:changed
template	YAML template load/save/validate; 17 field types in a registry
storage	Form .meta.json r/w, image bytes, per-template storage layout
form	Storage workspace orchestration (template + storage + config defaults)
index	Per-profile SQLite cache of template/form metadata
dataprovider	Read-only facade composing index + render — used by wiki/api
render	raymond Handlebars + goldmark + chroma; per-target URL strategies
nav	formidable:// URL resolver; persists active selection
wiki	Runtime HTTP server hosting /, /template/..., /storage/...
api	/api/collections/* REST + OpenAPI 3.0.3 spec + Swagger UI
csv	CSV import/export helpers
i18n	Backend-rooted localization served to vue-i18n
dialog	Native file/folder pickers via Wails

Frontend (frontend/src/)

Vue 3 SPA with workspaces for Templates, Storage, Profiles, Settings, Information (server lifecycle, monitoring), and Plugins (placeholder). Calls the backend via Wails service bindings generated from each module's Service type — no IPC, no window.api shim. UI strings flow through vue-i18n from internal/modules/i18n/locales/.

Render pipeline

Transport-neutral. Each consumer constructs its own render.Manager with a (imageURLFunc, formidableLinkURLFunc) pair so the same Handlebars output can target the in-app slideout (data: URLs + formidable:// for the Vue interceptor), the wiki HTTP server (/storage/.../images/... + /template/.../form/...), or future exports (Azure DevOps Wiki, GitHub Wiki, plain MD) without a single branch inside the render module.

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Field types

15 stored types + 4 system/container, all driven from internal/modules/template/field_registry.go:

• Identity: guid
• Text: text, textarea
• Numeric: number, range
• Boolean: boolean
• Choice: dropdown, radio, multioption
• Date: date
• Collections: list, table, tags
• Media: image, link
• API-linked: api (selection from a sibling collection with mapped fields)
• Containers: loopstart / loopstop (and the looper virtual type — repeating sections, max nesting depth 2)

Templates with enable_collection: true AND a guid field become addressable via /api/collections/{stem}/{guid} and surface in /api/collections.

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REST API

GET /api/docs/ for the live Swagger UI; GET /api/openapi.json for the spec (rebuilt per request from current templates). Endpoints:

GET    /api/guid                                     — server-minted UUID v4
GET    /api/collections                              — list collection-enabled templates
GET    /api/collections/{tpl}                        — paged list (limit/offset/q/tags + ETag)
GET    /api/collections/{tpl}/count                  — total
GET    /api/collections/{tpl}/design                 — fields with normalized options
GET    /api/collections/{tpl}/{id}                   — full meta+data (ETag)
HEAD   /api/collections/{tpl}/{id}                   — ETag-only freshness check
POST   /api/collections/{tpl}                        — create (?upsert=true to overwrite)
PUT    /api/collections/{tpl}/{id}                   — replace (?upsert=true to create)
PATCH  /api/collections/{tpl}/{id}                   — shallow-merge (optional If-Match → 412)
PATCH  /api/collections/{tpl}/{id}/field/{key}       — single-field update
DELETE /api/collections/{tpl}/{id}                   — 204
POST   /api/collections/{tpl}/batch?mode=...         — bulk create|replace|merge
GET    /api/collections/{tpl}/export.ndjson          — full streamed export
GET    /api/collections/{tpl}/export.csv             — id/filename/title/tags

{id} is always the GUID value (the field whose type: guid), never the filename. Filenames are derived from the template's item_field via slugify with collision suffix (brood.meta.json, brood-2.meta.json, …) and fall back to <guid>.meta.json.

POST auto-mints a GUID server-side when the body's data[guidKey] is empty, so callers don't need a UUID library.

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Template syntax

raymond (vendored fork in third_party/raymond/) + goldmark + chroma:

# {{field "title"}}

{{#if (fieldRaw "check")}}
Enabled
{{else}}
Disabled
{{/if}}

## Tags
{{#each (fieldRaw "tags")}}
- {{this}}
{{/each}}

## Table
{{#if (fieldRaw "rows")}}
| Col1 | Col2 |
|------|------|
{{#each (fieldRaw "rows")}}
| {{this.0}} | {{this.1}} |
{{/each}}
{{/if}}

Helpers: field, fieldRaw, fieldMeta, tags, stats, plus the math/comparison families. See internal/modules/render/helpers.go.

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Build & run

Requires Go 1.25+, Node 20+, and the Wails 3 CLI:

go install github.com/wailsapp/wails/v3/cmd/wails3@latest

Then via Task:

task dev          # build + run; clean exit on window close
task dev:watch    # hot-reload via vite + wails3 dev
task build        # build the binary into ./bin/Formidable
task package      # platform installer (.deb / .rpm / .dmg / .exe)

Linux packaging is .deb / .rpm / Arch via nfpm; the binary runs as /usr/local/bin/Formidable and the .desktop entry as Formidable.

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Tests

TDD throughout — every behavior has either a unit test or a Gherkin scenario before the implementation lands.

go test -race ./...                              # whole tree, race detector on
go test -race -v ./internal/modules/api/...      # one module, verbose

The api module alone ships 104 godog scenarios + 682 steps; the wiki module 39; render 88; storage and template each well into the dozens. Feature files live under each module's features/ folder.

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Layout

internal/
  app/                       — composition root (single boot wiring)
  log/                       — slog setup
  modules/                   — domain modules (table above)
frontend/
  src/                       — Vue 3 SPA
  bindings/                  — generated Wails service stubs
build/                       — Wails per-platform targets, nfpm.yaml, appicon.png
third_party/raymond/         — vendored Handlebars fork (whitespace + options-only patches)
Examples/                    — sample templates & storage (basic, loopie, recepten)
design/                      — port findings, source docs (read-only reference)
main.go                      — Wails app entry point
Taskfile.yml                 — task entry points

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License

MIT © 2026 Peter van de Pas

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Acknowledgments

• Wails — Go + webview desktop framework
• Vue 3 — frontend framework
• raymond — Handlebars-for-Go (vendored fork)
• goldmark — CommonMark in Go
• chroma — syntax highlighting
• godog — Gherkin BDD for Go
• Swagger UI — bundled API explorer
• modernc.org/sqlite — pure-Go SQLite

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Links

• Repo: https://github.com/petervdpas/Formidable2
• Original (Electron) Formidable: https://github.com/petervdpas/Formidable
• GiGot (token-based remote sync, future integration): https://github.com/petervdpas/GiGot