xtemplate

Hypermedia web apps from a directory of Go templates.

xtemplate is a Go server that treats templates as handlers: file-based routing, a request-scoped dot context, and first-class static files; no separate application layer.

<!-- contacts.html  →  GET /contacts (SQL provider configured as .DB) -->
<ul>
  {{range .DB.QueryRows `SELECT id, name FROM contacts`}}
  <li><a href="/contacts/{{.id}}">{{.name}}</a></li>
  {{end}}
</ul>

<!-- contacts/{id}.html  →  GET /contacts/{id} -->
{{$id := .Req.PathValue `id`}}
{{$c := .DB.QueryRow `SELECT id, name, phone, email FROM contacts WHERE id = ?` $id}}
<form method="POST">
  <input name="name"  value="{{$c.name}}">
  <input name="phone" value="{{$c.phone}}">
  <input name="email" value="{{$c.email}}">
  <button>Update</button>
</form>

{{define "POST /contacts/{id}"}}
{{$_ := .DB.Exec `UPDATE contacts SET name=?, phone=?, email=? WHERE id = ?`
    (.Req.FormValue `name`) (.Req.FormValue `phone`)
    (.Req.FormValue `email`) (.Req.PathValue `id`)}}
{{template `/contacts/{id}.html` .}}
{{end}}

No route table, no handler functions. One file for the index. One file for the form and the update. Path parameters, form values, and SQL all hang off the dot context.

Philosophy

Deal with the first-class citizens of the web: paths, requests, HTML responses, and backing data. Templates are expressive enough to be the app. More details in Design.

Highlights

• File-based routing - admin/settings.html serves GET /admin/settings; index.html serves the directory. Template semantics
• Any method and pattern - {{define "DELETE /contact/{id}"}} is a route. Instance loading
• Loads once, reloads live - parse at startup; swap an immutable instance on change. Design
• Dot context - .Req, .Resp, .DB, .FS, … per request. Dot context
• Safe by default - html/template escaping; optional sanitize / trust helpers. Functions
• Optimal static files - hashes, SRI, precompressed encodings, long cache. Instance loading
• SSE - {{define "SSE /path"}} for live updates. Dot context → Flush
• Embeddable - CLI, Docker, Caddy plugin, or http.Handler library. Deployment modes

Some more patterns:

{{- with $hash := .X.StaticFileHash `/assets/reset.css`}}
<link rel="stylesheet" href="/assets/reset.css?hash={{$hash}}" integrity="{{$hash}}">
{{- end}}

{{- define "SSE /reload"}}{{.Flush.WaitForServerStop}}data: reload{{printf "\n\n"}}{{end}}
<script>new EventSource("/reload").onmessage = () => location.reload()</script>

More complete apps: examples/.

Quick start

# CLI (live reload)
go install github.com/infogulch/xtemplate/cmd/xtemplate@latest
mkdir -p templates && echo '<h1>{{.Req.URL.Path}}</h1>' > templates/index.html
xtemplate --listen :8080
# open http://localhost:8080

# Docker
docker run --rm -p 8080:80 \
  -v "$PWD/templates:/app/templates:ro" \
  infogulch/xtemplate:latest

# Caddy
:8080
route {
	xtemplate
}

Full integration map and configs: docs/reference/deployment-modes.md.

All documentation (tutorial, how-tos, reference, design): docs/.

Public users

• infogulch/todoxt - Todos app built with xtemplate and htmx
• infogulch/rssxt - RSS reader

Contributing

Development setup, repo map, and tests: CONTRIBUTING.md (same as docs/contributing.md).

History and license

Evolved from go-htmx and a Caddy-centric prototype into a standalone library with an optional Caddy module. Narrative: Project history. Releases: CHANGELOG.md.

Licensed under the Apache 2.0 license. See LICENSE.