feat: new override argument to pass metadata (#52)

Co-authored-by: Christophe Dervieux <christophe.dervieux@gmail.com>

DESCRIPTION

@@ -1,6 +1,6 @@
 Package: quarto
 Title: R Interface to 'Quarto' Markdown Publishing System
-Version: 1.3.1
+Version: 1.3.2
 Authors@R: 
     person("JJ", "Allaire", , "jj@rstudio.com", role = c("aut", "cre"),
            comment = c(ORCID = "0000-0003-0174-9868"))

NEWS.md

@@ -1,5 +1,7 @@
 # quarto (development version)
 
+* Add `metadata` and `metadata_file` to `quarto_render()` to pass modify Quarto metadata from calling render. If both are set, `metadata` will be merged over `metadata_file` content. Internally, metadata will be passed as a `--metadata-file` to `quarto render` (thanks, @mcanouil, #52, @maelle, #49).
+
 * Added a `NEWS.md` file to track changes to the package.
 
 * `execute_params` in `quarto_render()` now converts boolean value to `true/false` correctly as expected by `quarto render` (thanks, @marianklose, #124).

R/render.R

@@ -25,8 +25,15 @@
 #' @param use_freezer Force use of frozen computations for an incremental
 #'  file render.
 #' @param cache Cache execution output (uses knitr cache and jupyter-cache
-#'   respectively for Rmd and Jupyter input files).
+#'  respectively for Rmd and Jupyter input files).
 #' @param cache_refresh Force refresh of execution cache.
+#' @param metadata An optional named list used to override YAML
+#'   metadata. It will be passed as a YAML file to `--metadata-file` CLI flag.
+#'   This will be merged over `metadata-file` options if both are
+#'   specified.
+#' @param metadata_file A yaml file passed to `--metadata-file` CLI flags to
+#'   overrite metadata. This will be merged with `metadata` if both are
+#'   specified, with low precedence on `metadata` options.
 #' @param debug Leave intermediate files in place after render.
 #' @param quiet Suppress warning and other messages.
 #' @param pandoc_args Additional command line options to pass to pandoc.
@@ -48,6 +55,9 @@
 #'
 #' # Render Jupyter Markdown
 #' quarto_render("notebook.md")
+#'
+#' # Override metadata
+#' quarto_render("notebook.Rmd", override = list(lang = "fr", echo = "false"))
 #' }
 #' @export
 quarto_render <- function(input = NULL,
@@ -62,6 +72,8 @@ quarto_render <- function(input = NULL,
                           use_freezer = FALSE,
                           cache = NULL,
                           cache_refresh = FALSE,
+                          metadata = NULL,
+                          metadata_file = NULL,
                           debug = FALSE,
                           quiet = FALSE,
                           pandoc_args = NULL,
@@ -136,6 +148,19 @@ quarto_render <- function(input = NULL,
   if (isTRUE(cache_refresh)) {
     args <- c(args, "--cache-refresh")
   }
+  # metadata to pass to quarto render
+  if (!missing(metadata)) {
+    # We merge meta if there is metadata_file passed
+    if (!missing(metadata_file)) {
+      metadata <- merge_list(yaml::read_yaml(metadata_file, eval.expr = FALSE), metadata)
+    }
+    meta_file <- tempfile(pattern = "quarto-meta", fileext = ".yml")
+    on.exit(unlink(meta_file), add = TRUE)
+    write_yaml(metadata, meta_file)
+    args <- c(args, "--metadata-file", meta_file)
+  } else if (!missing(metadata_file)) {
+    args <- c(args, "--metadata-file", metadata_file)
+  }
   if (isTRUE(debug)) {
     args <- c(args, "--debug")
   }
@@ -152,9 +177,3 @@ quarto_render <- function(input = NULL,
   # no return value
   invisible(NULL)
 }
-
-
-
-
-
-

R/utils.R

@@ -15,3 +15,10 @@ write_yaml <- function(x, file) {
   })
   yaml::write_yaml(x, file, handlers = handlers)
 }
+
+
+# inline knitr:::merge_list()
+merge_list <- function(x, y) {
+  x[names(y)] <- y
+  x
+}

tests/testthat/_snaps/render/metadata-file.test.out

@@ -0,0 +1,6 @@
+Pandoc
+  Meta
+    { unMeta =
+        fromList [ ( "title" , MetaInlines [ Str "test" ] ) ]
+    }
+  [ Para [ Str "content" ] ]

tests/testthat/_snaps/render/metadata-merged.test.out

@@ -0,0 +1,6 @@
+Pandoc
+  Meta
+    { unMeta =
+        fromList [ ( "title" , MetaInlines [ Str "test2" ] ) ]
+    }
+  [ Para [ Str "content" ] ]

tests/testthat/_snaps/render/metadata.test.out

@@ -0,0 +1,6 @@
+Pandoc
+  Meta
+    { unMeta =
+        fromList [ ( "title" , MetaInlines [ Str "test" ] ) ]
+    }
+  [ Para [ Str "content" ] ]

tests/testthat/helper.R

@@ -9,22 +9,49 @@ skip_if_quarto <- function() {
 local_qmd_file <- function(..., .env = parent.frame()) {
   skip_if_not_installed("xfun")
   skip_if_not_installed("withr")
-  path <- withr::local_tempfile(.local_envir = .env, fileext = ".qmd")
+  # create a directory to delete for correct cleaning
+  dir <- withr::local_tempdir("quarto-test", .local_envir = .env)
+  # create a file in this directory
+  path <- withr::local_tempfile(tmpdir = dir, fileext = ".qmd", .local_envir = .env)
   xfun::write_utf8(c(...), path)
   path
 }
 
-.render <- function(input, ...) {
+.render <- function(input, output_file = NULL, ..., .env = parent.frame()) {
   skip_if_no_quarto()
-  output_file <- xfun::with_ext(basename(input), "test.out")
-  quarto_render(input, output_file = output_file, quiet = TRUE, ...)
-  output_file
+  skip_if_not_installed("withr")
+  # work inside input directory
+  withr::local_dir(dirname(input))
+  if (is.null(output_file)) {
+    output_file <- basename(withr::local_file(
+      xfun::with_ext(input, "test.out"),
+      .local_envir = .env
+    ))
+  }
+  quarto_render(basename(input), output_file = output_file, quiet = TRUE, ...)
+  expect_true(file.exists(output_file))
+  normalizePath(output_file)
 }
 
 .render_and_read <- function(input, ...) {
   skip_if_not_installed("xfun")
   skip_if_not_installed("withr")
   out <- .render(input, ...)
-  withr::local_dir(dirname(input))
   xfun::read_utf8(out)
 }
+
+expect_snapshot_qmd_output <- function(name, input, output_file = NULL, ...) {
+  local_edition(3)
+  skip_if_not_installed("xfun")
+  name <- xfun::with_ext(name, ".test.out")
+
+  # Announce the file before touching `code`. This way, if `code`
+  # unexpectedly fails or skips, testthat will not auto-delete the
+  # corresponding snapshot file.
+  announce_snapshot_file(name = name)
+
+  # render with quarto and snapshot
+  output_file <- .render(input, output_file, ...)
+
+  expect_snapshot_file(output_file, name)
+}

tests/testthat/test-render.R

@@ -1,4 +1,3 @@
-
 test_that("An error is reported when Quarto is not installed", {
   skip_if_quarto()
   expect_error(quarto_render("test.Rmd"))
@@ -11,3 +10,38 @@ test_that("R Markdown documents can be rendered", {
   expect_true(file.exists("test.html"))
   unlink("test.html")
 })
+
+test_that("metadata argument works in quarto_render", {
+  skip_if_no_quarto()
+  qmd <- local_qmd_file(c("content"))
+  # metadata
+  expect_snapshot_qmd_output(name = "metadata", input = qmd, output_format = "native", metadata = list(title = "test"))
+})
+
+test_that("metadata-file argument works in quarto_render", {
+  skip_if_no_quarto()
+  skip_if_not_installed("withr")
+  qmd <- local_qmd_file(c("content"))
+  yaml <- withr::local_tempfile(fileext = ".yml")
+  write_yaml(list(title = "test"), yaml)
+  expect_snapshot_qmd_output(
+    name = "metadata-file",
+    input = qmd,
+    output_format = "native",
+    metadata_file = yaml
+  )
+})
+
+test_that("metadata-file and metadata are merged in quarto_render", {
+  skip_if_no_quarto()
+  skip_if_not_installed("withr")
+  qmd <- local_qmd_file(c("content"))
+  yaml <- withr::local_tempfile(fileext = ".yml")
+  write_yaml(list(title = "test"), yaml)
+  expect_snapshot_qmd_output(
+    name = "metadata-merged",
+    input = qmd,
+    output_format = "native",
+    metadata_file = yaml, metadata = list(title = "test2")
+  )
+})