Vignette engines for Quarto

DESCRIPTION

@@ -9,7 +9,7 @@ Authors@R:
            comment = c(ORCID = "0000-0003-0174-9868"))
 Description: Convert R Markdown documents and 'Jupyter' notebooks to a variety of
   output formats using 'Quarto'.
-Imports: utils,rmarkdown,jsonlite,yaml,processx,rstudioapi,later,rsconnect (>= 0.8.26)
+Imports: tools,utils,rmarkdown,jsonlite,yaml,processx,rstudioapi,later,rsconnect (>= 0.8.26)
 Suggests: 
     knitr,
     testthat (>= 3.1.0)
@@ -21,4 +21,4 @@ Encoding: UTF-8
 Roxygen: list(markdown = TRUE)
 RoxygenNote: 7.2.3
 Config/testthat/edition: 3
-VignetteBuilder: knitr
+VignetteBuilder: knitr,quarto

NAMESPACE

@@ -16,5 +16,6 @@ importFrom(processx,process)
 importFrom(rmarkdown,relative_to)
 importFrom(rstudioapi,isAvailable)
 importFrom(rstudioapi,viewer)
+importFrom(tools,vignetteEngine)
 importFrom(utils,browseURL)
 importFrom(yaml,write_yaml)

R/zzz.R

@@ -0,0 +1,24 @@
+
+#' Register engines to support Quarto vignettes
+#' @importFrom tools vignetteEngine
+#' @noRd
+.onLoad <- function(libname, pkgname) { # args ignored
+  vignetteEngine(name = "pdf",
+                 package = "quarto",
+                 pattern = "[.]qmd$",
+                 weave = function(file, ..., encoding = "UTF-8") {
+                   quarto_render(file, ..., output_format = "pdf")
+                 },
+                 tangle = vignetteEngine("knitr::rmarkdown")$tangle,
+                 aspell = vignetteEngine("knitr::rmarkdown")$aspell
+                 )
+  vignetteEngine(name = "html",
+                 package = "quarto",
+                 pattern = "[.]qmd$",
+                 weave = function(file, ..., encoding = "UTF-8") {
+                   quarto_render(file, ..., output_format = "html")
+                 },
+                 tangle = vignetteEngine("knitr::rmarkdown")$tangle,
+                 aspell = vignetteEngine("knitr::rmarkdown")$aspell
+                 )
+}

vignettes/hello.qmd

@@ -0,0 +1,36 @@
+---
+title: "Quarto Vignettes"
+format:
+  pdf:
+    toc: false
+  html:
+    toc: true
+vignette: >
+  %\VignetteIndexEntry{Vignettes}
+  %\VignetteEngine{quarto::pdf}
+  %\VignetteEncoding{UTF-8}
+---
+
+## Hello Vignette World!
+
+This is an example Quarto vignette, demonstrating how the **quarto** package can let you write package vignettes in Quarto.
+
+## Two Vignette Engines
+
+The **quarto** package registers 2 vignette engines, `quarto::pdf` and `quarto::html`. Either of these may be selected in a Quarto vignette's YAML header. For example, this vignette's header reads:
+```yaml
+---
+title: "Quarto Vignettes"
+format:
+  pdf:
+    toc: false
+  html:
+    toc: true
+vignette: >
+  %\VignetteIndexEntry{Vignettes}
+  %\VignetteEngine{quarto::pdf}
+  %\VignetteEncoding{UTF-8}
+---
+```
+
+Consequently, a PDF version of this vignette is built.