fix #932: deprecate the clean_envir argument of render_book(), and use xfun::Rscript_call() to render multiple output formats (with each format in a new R session, so the formats aren rendered independently)

Author: yihui

DESCRIPTION

@@ -1,7 +1,7 @@
 Package: bookdown
 Type: Package
 Title: Authoring Books and Technical Documents with R Markdown
-Version: 0.20.4
+Version: 0.20.5
 Authors@R: c(
     person("Yihui", "Xie", role = c("aut", "cre"), email = "xie@yihui.name", comment = c(ORCID = "0000-0003-0645-5666")),
     person("JJ", "Allaire", role = "ctb"),
@@ -62,7 +62,7 @@ Imports:
     htmltools (>= 0.3.6),
     knitr (>= 1.22),
     rmarkdown (>= 2.3),
-    xfun (>= 0.6),
+    xfun (>= 0.13),
     tinytex (>= 0.12)
 Suggests:
     htmlwidgets,

NEWS.md

@@ -6,10 +6,12 @@
 
 - Make sure `search_index.json` contains valid characters for the JSON format (thanks, @wlandau, #913).
 
-## MINOR CHANGES
+## MAJOR CHANGES
 
 - The `--file-scope` behavior introduced in bookdown v0.20 is now disabled by default. This is due to broken TOC links for duplicate section names (e.g., "Exercises"; see #909) that have automatically generated identifiers.
 
+- The `clean_envir` argument of `bookdown::render_book()` has been deprecated and will be removed in the future (thanks, @jenslaufer, #932).
+
 # CHANGES IN bookdown VERSION 0.20
 
 ## NEW FEATURES

R/render.R

@@ -15,9 +15,8 @@
 #' @param output_format,...,clean,envir Arguments to be passed to
 #'   \code{rmarkdown::\link{render}()}. For \code{preview_chapter()}, \code{...}
 #'   is passed to \code{render_book()}.
-#' @param clean_envir Whether to clean up the environment \code{envir} before
-#'   rendering the book. By default, the environment is cleaned when rendering
-#'   the book in a non-interactive R session.
+#' @param clean_envir This argument has been deprecated and will be removed in
+#'   future versions of \pkg{bookdown}.
 #' @param output_dir The output directory. If \code{NULL}, a field named
 #'   \code{output_dir} in the configuration file \file{_bookdown.yml} will be
 #'   used (possibly not specified, either, in which case a directory name
@@ -51,15 +50,18 @@ render_book = function(
       output_format = rmarkdown::all_output_formats(input)
     }
     if (length(output_format) > 1) {
-      return(unlist(lapply(output_format, function(fmt) render_book(
+      return(unlist(lapply(output_format, function(fmt) xfun::Rscript_call(render_book, list(
         input, fmt, ..., clean = clean, envir = envir, output_dir = output_dir,
         new_session = new_session, preview = preview, config_file = config_file
-      ))))
+      )))))
     }
     format = target_format(output_format)
   }
 
-  if (clean_envir) rm(list = ls(envir, all.names = TRUE), envir = envir)
+  if (!missing(clean_envir)) warning(
+    "The argument 'clean_envir' has been deprecated and will be removed in future ",
+    "versions of bookdown."
+  )
 
   if (config_file != '_bookdown.yml') {
     unlink(tmp_config <- tempfile('_bookdown_', '.', '.yml'))