feat(mermaid): add dir.dest argument

Refs #14

R/mermaid.R

@@ -12,7 +12,10 @@
 #' @param diagram Diagram in mermaid markdown-like language or file (as a connection or file name) containing a diagram specification
 #' @param theme Mermaid theme (See https://mermaid.js.org/config/theming.html#available-themes)
 #' @param format Image format (either `"jpg"`, or `"png"`, or `"svg"`)
-#' @param file.dest Path to the downloaded image
+#' @param dir.dest Destination folder for the downloaded image. This parameter is
+#' ignored if `file.dest` contains a folder path.
+#' @param file.dest Path to the downloaded image. It's combined with `dir.dest`
+#' if it only contains the name of the file without a folder path.
 #' @param link Link generated by [mermaid_gen_link]
 #' @param server URL of the server used to generate the link
 #'
@@ -35,9 +38,11 @@
 mermaid <- function(diagram,
                     format = "png",
                     theme = "default",
-                    file.dest = file.path(tempdir(),
-                                          paste0(rlang::hash(link), ".", format)),
+                    dir.dest = tempdir(),
+                    file.dest = paste0(rlang::hash(link), ".", format),
                     link = mermaid_gen_link(diagram, theme = theme, format = format)) {
+  if (!dir.exists(dir.dest)) dir.create(dir.dest, recursive = TRUE, showWarnings = FALSE)
+  if (dirname(file.dest) == ".") file.dest <- file.path(dir.dest, file.dest)
   if (!file.exists(file.dest)) {
     download.file(link, file.dest, quiet = TRUE, mode = "wb")
   }

man/mermaid.Rd

@@ -9,7 +9,8 @@ mermaid(
   diagram,
   format = "png",
   theme = "default",
-  file.dest = file.path(tempdir(), paste0(rlang::hash(link), ".", format)),
+  dir.dest = tempdir(),
+  file.dest = paste0(rlang::hash(link), ".", format),
   link = mermaid_gen_link(diagram, theme = theme, format = format)
 )
 
@@ -27,7 +28,11 @@ mermaid_gen_link(
 
 \item{theme}{Mermaid theme (See https://mermaid.js.org/config/theming.html#available-themes)}
 
-\item{file.dest}{Path to the downloaded image}
+\item{dir.dest}{Destination folder for the downloaded image. This parameter is
+ignored if \code{file.dest} contains a folder path.}
+
+\item{file.dest}{Path to the downloaded image. It's combined with \code{dir.dest}
+if it only contains the name of the file without a folder path.}
 
 \item{link}{Link generated by \link{mermaid_gen_link}}
 

tests/testthat/test-mermaid.R

@@ -15,5 +15,15 @@ test_that("mermaid_gen_link: conversion of mmd to pako works", {
 
 test_that("mermaid returns a file", {
   f <- mermaid(diagram)
+  file.dest <- basename(f)
+  expect_true(file.exists(f))
+  f <- mermaid(diagram, file.dest = "toto.png")
+  expect_equal(f, file.path(tempdir(), "toto.png"))
+  expect_true(file.exists(f))
+  f <- mermaid(diagram, dir.dest = file.path(tempdir(), "try-me"))
+  expect_equal(f, file.path(tempdir(), "try-me", file.dest))
+  expect_true(file.exists(f))
+  f <- mermaid(diagram, dir.dest = file.path(tempdir(), "try-me"), file.dest = "toto.png")
+  expect_equal(f, file.path(tempdir(), "try-me", "toto.png"))
   expect_true(file.exists(f))
 })