attempt at Chadwick installation checks; #307 (#311)

NAMESPACE

@@ -6,7 +6,12 @@ export(bref_daily_batter)
 export(bref_daily_pitcher)
 export(bref_standings_on_date)
 export(bref_team_results)
+export(chadwick_find_lib)
+export(chadwick_is_installed)
+export(chadwick_ld_library_path)
+export(chadwick_path)
 export(chadwick_player_lu)
+export(chadwick_set_ld_library_path)
 export(code_barrel)
 export(daily_batter_bref)
 export(daily_pitcher_bref)

R/chadwick_installation.R

@@ -0,0 +1,103 @@
+#' @title Check Chadwick installation
+#' @description
+#' Utility functions to help ensure that Chadwick is set up correctly. 
+#' @return If Chadwick is not installed `NULL`. If Chadwick is installed, the path to the `cwevent` binary.
+#' @export
+#' @examples
+#' chadwick_path()
+#' 
+
+chadwick_path <- function() {
+  if (.Platform$OS.type == "windows") {
+    cmd <- "where"
+  } else {
+    cmd <- "which"
+  }
+
+  path <- tryCatch(
+    system2(cmd, "cwevent", stdout = TRUE),
+    warning = function(w) {
+      message("cwevent is not installed. Please see https://github.com/chadwickbureau/chadwick/releases for installation instructions. ")
+    }
+  )
+  if (!is.null(path) && file.exists(path)) {
+    return(dirname(path))
+  }
+}
+
+#' @rdname chadwick_path
+#' @return `TRUE` or `FALSE`
+#' @export
+#' @examples
+#' chadwick_is_installed()
+#' 
+
+chadwick_is_installed <- function() {
+  path <- chadwick_path()
+  !is.null(path) && file.exists(path)
+}
+
+#' @rdname chadwick_path
+#' @export
+#' @return Path to the Chadwick shared library. 
+#' @examples
+#' chadwick_find_lib()
+
+chadwick_find_lib <- function() {
+  if (!is.null(cw_path <- chadwick_path())) {
+    system2(
+      "find", 
+      paste(dirname(cw_path), '-name "libchadwick*"'), stdout = TRUE
+    ) |>
+      dirname() |>
+      unique()
+  }
+}
+
+#' @rdname chadwick_path
+#' @export
+
+chadwick_set_ld_library_path <- function() {
+  new_ld_library_path <- paste(
+    chadwick_find_lib(), 
+    Sys.getenv("LD_LIBRARY_PATH"), 
+    sep = ":"
+  )
+  Sys.setenv(LD_LIBRARY_PATH = new_ld_library_path)
+}
+
+#' @rdname chadwick_path
+#' @description
+#' The easiest way for the [Chadwick CLI](https://github.com/chadwickbureau/chadwick/releases) 
+#' tools to work on *nix systems is to
+#' set the `LD_LIBRARY_PATH` environment variable. Unfortunately this environment
+#' variable is not set by default during the Chadwick installation. 
+#' 
+#' `chadwick_ld_library_path()` checks to find the Chadwick shared libraries, and then
+#' set the `LD_LIBRARY_PATH` environment variable. 
+#' If `chadwick_ld_library_path()` returns `TRUE`, the `cwevent` command line program 
+#' that \code{\link{retrosheet_data}}
+#' depends on should work. 
+#' 
+#' The other functions documented here are mostly for internal use. 
+#' 
+#' @export
+#' @seealso [retrosheet_data()]
+#' @examples
+#' \dontrun{
+#' if (chadwick_ld_library_path()) {
+#'   retrosheet_data(tempdir())
+#' }
+#' }
+
+chadwick_ld_library_path <- function() {
+  old_ld_library_paths <- Sys.getenv("LD_LIBRARY_PATH") |>
+    stringr::str_split_1(pattern = ":")
+  if (!chadwick_find_lib() %in% old_ld_library_paths) {
+    chadwick_set_ld_library_path()
+  }
+  new_ld_library_paths <- Sys.getenv("LD_LIBRARY_PATH") |>
+    stringr::str_split_1(pattern = ":")
+  chadwick_find_lib() %in% new_ld_library_paths
+}
+