---
title: "Automate document builds"
output:
  html:
    meta:
      css: default
vignette: >
  %\VignetteIndexEntry{Automate document builds}
  %\VignetteEngine{litedown::vignette}
  %\VignetteEncoding{UTF-8}
---

The rendering functions make document builds explicit and repeatable.
A small `Makefile` can express the same commands used interactively while
rebuilding an output only after its source changes:

``` make
.PHONY: all clean

all: resume.html resume.pdf cover-letter.html cover-letter.pdf

resume.html resume.pdf: resume.Rmd
	Rscript -e 'liteformats::resume("$<", "$@")'

cover-letter.html cover-letter.pdf: cover-letter.Rmd
	Rscript -e 'liteformats::cover_letter("$<", "$@")'

clean:
	$(RM) resume.html resume.pdf cover-letter.html cover-letter.pdf
```

Run `make` to build every target, or name one target such as
`make cover-letter.pdf`. Each recipe exposes the underlying R command,
so it can include project-specific options, preprocessing, postprocessing,
or other dependencies.

## Rendering model

Each render has two stages. First, `litedown::fuse(..., "markdown")` evaluates
R code and YAML. Then `litedown::mark()` applies the format's HTML template.
This order means inline R values work in metadata as well as in the document
body.

PDF uses that self-contained HTML as its input and prints it with
`xfun::browser_print()`. As a result, the source and R dependencies are the
same for HTML and PDF; PDF additionally requires a local Chromium-based
browser. Vignette and automated check workflows can build HTML without adding
that browser requirement.

For render time overrides, pass the matching options helper in the recipe as
shown in `vignette("config")`.