# Default export templates (ADR-0011)

`student.typ` / `teacher.typ` are the **framework default templates**. In a real
engineering file they live at `exports/student.typ` / `exports/teacher.typ`; the
project-creation flow seeds copies there (out of scope here — see ADR-0011 Open
Questions). They are kept here as the canonical, copyable defaults and for the
offline smoke test below.

Each template:

1. reads the injected manifest: `toml(sys.inputs.manifest)`;
2. loops `manifest.parts`, `include`-ing each content field via a computed
   **root-relative absolute** path `/<part.path>/<field>.typ`, and reading scalar
   fields (example `source`) from `/<part.path>/element.toml`;
3. assembles a `parts` array and calls `cph-render`'s `render-lesson(...)`,
   passing the per-level heading numbering (presentation lives in the template).

## Why the include loop is in the template, not in cph-render

typst resolves a dynamic `include`/`toml` path relative to **the file the call
lexically appears in**, and a package (`@local/cph-render`) has its **own virtual
root**. A dynamic `include` written inside the package resolves against the
*package* dir — even an absolute `/segments/x.typ` — never the engineering
`--root`. Verified empirically. The template lives under `--root`, so its
`/<part.path>/<field>.typ` resolves against `--root`. Hence the template loads
content and hands `render-lesson` an already-assembled `parts` array;
`render-lesson` never includes anything.

## Key path facts for the engine

- **Template is the typst main file.** Compile it directly.
- **`--root` = engineering-file root.** Content `include`s use absolute
  root-relative paths.
- **Manifest is injected as a root-relative ABSOLUTE path**:
  `--input manifest=/manifest.toml`. `toml(sys.inputs.manifest)` resolves
  relative to the *template's* location (`exports/`), so a bare
  `manifest=manifest.toml` would look in `exports/`. Pass the leading `/`.
- **Optional content presence** (lemma `proof`): typst has no file-exists
  primitive, so the template cannot probe disk. It reads a per-part `fields`
  array from the manifest listing the content fields present on disk. *(OPEN: the
  exact manifest shape for this is for the Rust/manifest contract to pin.)*

## Offline smoke test

`@local/cph-render` is resolved from a local-packages dir (a symlink to the
render package root — regenerable, test-only):

```sh
cd render
# one-time: make @local/cph-render resolvable offline
mkdir -p vendor/local-packages/local/cph-render
ln -sfn "$(pwd)" vendor/local-packages/local/cph-render/0.1.0

# compile a template against the smoke engineering file
typst compile --root examples/smoke-eng \
  --package-path ./vendor/local-packages \
  --package-cache-path ./vendor/typst-packages \
  --input manifest=/manifest.toml \
  examples/smoke-eng/exports/student.typ /tmp/cph-tmpl-student.pdf
```

(`examples/smoke-eng/exports/{student,teacher}.typ` are copies of the defaults
here, mirroring how a real engineering file carries its own templates.)
