Add split_bib to bs4_book (rstudio#1185)

`split_bib = FALSE` by default for this format though as before.

Co-authored-by: Christophe Dervieux <[email protected]>

DESCRIPTION

@@ -1,7 +1,7 @@
 Package: bookdown
 Type: Package
 Title: Authoring Books and Technical Documents with R Markdown
-Version: 0.22.14
+Version: 0.22.15
 Authors@R: c(
     person("Yihui", "Xie", role = c("aut", "cre"), email = "[email protected]", comment = c(ORCID = "0000-0003-0645-5666")),
     person("JJ", "Allaire", role = "ctb"),

NEWS.md

@@ -1,5 +1,7 @@
 # CHANGES IN bookdown VERSION 0.23
 
+- `bs4_book(splib_bib = TRUE)` can now be specified to have the same effect as in `gitbook()`. References will be shown at the end of each chapter and not only at the end of the book. This is useful with `bs4_book()` when a citation style not supporting footnotes is used because in that case, references are not shown inline in popups (thanks, @shirdekel, #1185).
+
 - For HTML book formats, a default `404.html` page will now be created if none exists already. This page can be customized by adding a `_404.md` or `_404.Rmd` file which will be rendered to HTML and inserted in the book. Most web serving platforms (e.g. Netlify, GH Pages, etc.) will use this file named `404.html` in the root as a custom error page. Otherwise, like browsers do, a default 404 page is shown. For context, a 404 error indicates that the file can’t be found, and it happens when a browser can’t find a requested web page. This could happen with your online book if you shared a link to a section but change the name of this section leading to a change in url (#1035).
 
 - In `bs4_book()`, improvement regarding copy button:

R/bs4_book.R

@@ -38,7 +38,7 @@
 #' @param repo Either link to repository where book is hosted, used to generate
 #'   view source and edit buttons or a list with repository `base` link, default
 #'   `branch`, `subdir` and `icon` (see "Specifying the repository").
-#' @param lib_dir,pandoc_args,extra_dependencies,... Passed on to
+#' @param lib_dir,pandoc_args,extra_dependencies,split_bib,... Passed on to
 #'   [rmarkdown::html_document()].
 #'
 #' @section Specifying the repository:
@@ -147,7 +147,8 @@ bs4_book <- function(theme = bs4_book_theme(),
                      ...,
                      lib_dir = "libs",
                      pandoc_args = NULL,
-                     extra_dependencies = NULL) {
+                     extra_dependencies = NULL,
+                     split_bib = FALSE) {
   check_packages(bs4_book_deps())
   bs4_check_dots(...)
 
@@ -175,7 +176,8 @@ bs4_book <- function(theme = bs4_book_theme(),
       output <- post(metadata, input, output, clean, verbose)
     }
 
-    output2 <- bs4_book_build(output, repo = repo, lib_dir = lib_dir)
+    output2 <- bs4_book_build(output, repo = repo, lib_dir = lib_dir,
+                              split_bib = split_bib)
 
     if (clean && file.exists(output) && !same_path(output, output2)) {
       file.remove(output)
@@ -200,7 +202,8 @@ bs4_book_theme <- function(primary = "#0068D9", ...) {
 bs4_book_build <- function(output = "bookdown.html",
                            repo = NULL,
                            lib_dir = "libs",
-                           output_dir = opts$get("output_dir")) {
+                           output_dir = opts$get("output_dir"),
+                           split_bib = split_bib) {
   move_files_html(output, lib_dir)
 
   rmd_index <- new.env(parent = emptyenv())
@@ -209,7 +212,7 @@ bs4_book_build <- function(output = "bookdown.html",
     build = function(...) bs4_book_page(..., rmd_index = rmd_index),
     number_sections = TRUE,
     split_by = "chapter",
-    split_bib = FALSE
+    split_bib = split_bib
   )
 
   move_files_html(output2, lib_dir)