make it possible to customize the knitting environment via knit_globa…

…l(envir) (#2358)

Co-authored-by: Yihui Xie <xie@yihui.name>

DESCRIPTION

@@ -1,7 +1,7 @@
 Package: knitr
 Type: Package
 Title: A General-Purpose Package for Dynamic Report Generation in R
-Version: 1.48.7
+Version: 1.48.8
 Authors@R: c(
     person("Yihui", "Xie", role = c("aut", "cre"), email = "xie@yihui.name", comment = c(ORCID = "0000-0003-0645-5666")),
     person("Abhraneel", "Sarma", role = "ctb"),

NEWS.md

@@ -6,6 +6,8 @@
 
 - Added support for `fig.alt` for LaTeX output, i.e., using `\includegraphics[alt={alt text}]` (thanks, @capnrefsmmat, #2378).
 
+- The environment in which code chunks are evaluated can be changed by passing a custom environment to `knit_glbal()` now (thanks, @abhsarma, #2358).
+
 ## BUG FIXES
 
 - In-chunk references of the form `<<label>>` should not be resolved if `label` is not found in the document (thanks, @jennybc @gadenbuie, #2360).

R/utils.R

@@ -561,18 +561,19 @@ fig_chunk = function(label, ext = '', number, fig.path = opts_chunk$get('fig.pat
   fig_path(ext, list(fig.path = fig.path, label = label), number)
 }
 
-#' The global environment in which code chunks are evaluated
+#' The global environment for evaluating code
 #'
-#' This function makes the environment of a code chunk accessible inside a
-#' chunk.
+#' Get or set the environment in which code chunks are evaluated.
 #'
-#' It returns the \code{envir} argument of \code{\link{knit}}, e.g. if we call
-#' \code{\link{knit}()} in the global environment, \code{knit_global()} returns
-#' R's global environment by default. You can call functions like
-#' \code{\link{ls}()} on this environment.
+#' @param envir If \code{NULL}, the function returns the \code{envir} argument
+#'   of \code{\link{knit}}, otherwise it should be a new environment for
+#'   evaluating code, in which case the function returns the old environment
+#'   after setting the new environment.
 #' @export
-knit_global = function() {
-  .knitEnv$knit_global %n% globalenv()
+knit_global = function(envir = NULL) {
+  old = .knitEnv$knit_global %n% globalenv()
+  if (!is.null(envir)) .knitEnv$knit_global = envir
+  old
 }
 
 # Indents a Block