Embed a file, multiple files, or directory on an HTML page

For a file, first encode it into base64 data (a character string). Then generate a hyperlink of the form <a href="base64 data" download="filename">Download filename</a>. The file can be downloaded when the link is clicked in modern web browsers. For a directory, it will be compressed as a zip archive first, and the zip file is passed to embed_file(). For multiple files, they are also compressed to a zip file first.

embed_file(path, name = basename(path), text = paste("Download", name), ...)

embed_dir(path, name = paste0(normalize_path(path), ".zip"), ...)

embed_files(path, name = with_ext(basename(path[1]), ".zip"), ...)

Arguments

path: Path to the file(s) or directory.
name: The default filename to use when downloading the file. Note that for embed_dir(), only the base name (of the zip filename) will be used.
text: The text for the hyperlink.
...: For embed_file(), additional arguments to be passed to html_tag() (e.g., class = 'foo'). For embed_dir() and embed_files(), arguments passed to embed_file().

Value

An HTML tag <a> with the appropriate attributes.

Details

These functions can be called in R code chunks in R Markdown documents with HTML output formats. You may embed an arbitrary file or directory in the HTML output file, so that readers of the HTML page can download it from the browser. A common use case is to embed data files for readers to download.

Note

Windows users may need to install Rtools to obtain the zip command to use embed_dir() and embed_files().

Internet Explorer does not support downloading embedded files. Chrome has a 2MB limit on the file size.

Examples

logo = xfun:::R_logo()
link = xfun::embed_file(logo, text = "Download R logo")
link
#> <a href="data:image/svg+xml;base64,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" download="Rlogo.svg">Download R logo</a>
if (interactive()) xfun::html_view(link)