savewidget from htmlwidget in R , cannot save html file in another folder

Question

I have a map leaflet that I want to save in an html file in a specific folder. I am using Windows 7.

I tried the following :

library(htmlwidgets)
saveWidget(map_leaflet, file="ressources/test.html")

library(htmlwidgets)
saveWidget(map_leaflet, file="ressources\\test.html")

library(htmlwidgets)
path_name <- file.path("ressources", "test.html", fsep="\\")
saveWidget(map_leaflet, file=path_name)

library(htmlwidgets)
path_name <- paste("ressources", "test.html", sep="/")
saveWidget(map_leaflet, file=path_name)

As an error message, depending on the Rstudio session, I either have

1) Error in setwd(dir) : cannot change working directory

2) Cannot find path

When I only save like this :

library(htmlwidgets)
saveWidget(map_leaflet, file="test.html")

It works perfectly.

Thank you in advance for your help.

Answer 1

Agreed.

here is a workaround:

f<-"ressources\\test.html"
saveWidget(map_leaflet,file.path(normalizePath(dirname(f)),basename(f)))

The issues appear to be that saveWidget does not work with relative pathnames and normalizePath does not work for paths to files that done exist yet.

I would call this a bug in saveWidget.

edit:

I have contribute what I think is an even better workaround to an existing open issue

Answer 2

I use the with_dir function in the withr package to do this. I also put it in a wrapper function:

save_leaflet <- function(plot, file, overwrite = FALSE){
  # save the file if it doesn't already exist or if overwrite == TRUE
  if( !file.exists(file) | overwrite ){
    withr::with_dir(new = dirname(file), 
                    code = htmlwidgets::saveWidget(plot, 
                                                   file = basename(file)))
  } else {
    print("File already exists and 'overwrite' == FALSE. Nothing saved to file.")
  }
}