Decode webR REPL link(s) to extract files to local directory

Decodes webR REPL sharelinks to extract the embedded files and save them to a local directory.

Usage

decode_webr_link(
  url,
  output_dir = file.path(tempdir(), "webr_files"),
  overwrite = FALSE,
  create_subdir = TRUE,
  name_dirs = TRUE,
  binary = FALSE
)

Arguments

url

Character string or vector containing webR REPL URL(s)

output_dir

Character string specifying the output directory path. Defaults to a webr_files directory inside the session temporary directory. Pass an explicit path to extract somewhere permanent.

overwrite

Logical. Whether to overwrite existing files. Defaults to FALSE.

create_subdir

Logical. If TRUE (default), each decoded link is extracted into its own subdirectory under output_dir rather than directly into it. For a single URL the subdirectory is named webr_<hash>, where <hash> is a short fingerprint of the URL. For multiple URLs, see name_dirs. Set FALSE to extract straight into output_dir.

name_dirs

Logical. For multiple URLs, controls how the per-link subdirectories are named.

TRUE (default) numbers them script_01, script_02, and so on.
FALSE names each one webr_<hash> from the URL fingerprint.

Ignored for a single URL, and ignored when create_subdir = FALSE (all files then extract into output_dir).

binary

Logical. Whether to write binary files held in the link (default: FALSE). A preview can show you text but not bytes, so a binary is left alone unless you ask for it.

Value

What comes back depends on how many URLs you pass.

For one URL, a webr_decoded object, which is a list with these entries.

files_info, a data frame of the files written, one row per file, with the columns filename, path, autorun, and size_bytes.
output_dir, the directory the files were written to.
url, the link that was decoded.
mode, the panels the link asks for, or NULL for all of them.
version, the webR version the link points at.
flags, the encoding flags read off the link.
total_files, how many files were written.
total_size, the size of those files in bytes.

For several URLs, a webr_decoded_batch object, which is a list with these entries.

results, a list of webr_decoded objects, one for each URL that decoded.
base_dir, the directory the per-link subdirectories sit under.
urls, the URLs you passed in, one per entry.
total_urls, how many URLs were handed in.
successful_urls, how many of them decoded.
total_files, how many files were written across every URL.
total_size, the size of those files in bytes.

Details

This is the reverse operation of creating webR links. Handles both single URLs and multiple URLs automatically.

Examples

# Round-trip: build a link, then decode it back to files
url <- as.character(webr_repl_link("plot(1:10)"))

result <- decode_webr_link(url)
#> Decompressing webR data...
#> Parsing file data...
#> Created directory: /tmp/RtmpjOtcTs/webr_files/webr_8430d3f5
#> Decoding 1 file...
#> script.R (10 bytes)
#> ✔ Successfully decoded 1 file to /tmp/RtmpjOtcTs/webr_files/webr_8430d3f5
print(result)
#> 
#> ── webR Decoded Files ──
#> 
#> Source:
#> <https://webr.r-wasm.org/latest/#code=eJyb2LwkLzE3dUVxclFmQYle0JKCxJKM7foZ%2Bbmp%2BuWpSfGlxalF%2BnDJktSKklUFOfklGoZWhgaaAC8DGLU%3D&mz>
#> Output: /tmp/RtmpjOtcTs/webr_files/webr_8430d3f5
#> 
#> Files (1):
#> script.R (10 bytes)
#> 
#> Version: "latest"
#> Encoding: "mz"

# Extract to a directory of your choosing
out <- file.path(tempdir(), "my_code")
decode_webr_link(url, output_dir = out, create_subdir = FALSE, overwrite = TRUE)
#> Decompressing webR data...
#> Parsing file data...
#> Created directory: /tmp/RtmpjOtcTs/my_code
#> Decoding 1 file...
#> script.R (10 bytes)
#> ✔ Successfully decoded 1 file to /tmp/RtmpjOtcTs/my_code
#> 
#> ── webR Decoded Files ──
#> 
#> Source:
#> <https://webr.r-wasm.org/latest/#code=eJyb2LwkLzE3dUVxclFmQYle0JKCxJKM7foZ%2Bbmp%2BuWpSfGlxalF%2BnDJktSKklUFOfklGoZWhgaaAC8DGLU%3D&mz>
#> Output: /tmp/RtmpjOtcTs/my_code
#> 
#> Files (1):
#> script.R (10 bytes)
#> 
#> Version: "latest"
#> Encoding: "mz"
list.files(out)
#> [1] "script.R"

# Several links at once
urls <- c(url, as.character(webr_repl_link("hist(rnorm(100))")))
decode_webr_link(urls, output_dir = file.path(tempdir(), "my_scripts"))
#> Processing 2 webR URLs...
#> 
#> 
#> ── Processing URL 1/2: script_01 
#> Decompressing webR data...
#> Parsing file data...
#> Created directory: /tmp/RtmpjOtcTs/my_scripts/script_01
#> Decoding 1 file...
#> script.R (10 bytes)
#> ✔ Successfully decoded 1 file to /tmp/RtmpjOtcTs/my_scripts/script_01
#> 
#> 
#> ── Processing URL 2/2: script_02 
#> Decompressing webR data...
#> Parsing file data...
#> Created directory: /tmp/RtmpjOtcTs/my_scripts/script_02
#> Decoding 1 file...
#> script.R (16 bytes)
#> ✔ Successfully decoded 1 file to /tmp/RtmpjOtcTs/my_scripts/script_02
#> 
#> ✔ Successfully processed 2/2 URLs
#> 
#> ── webR Decoded Batch ──
#> 
#> Base directory: /tmp/RtmpjOtcTs/my_scripts
#> Total URLs: 2
#> 
#> Successfully processed 2 URLs:
#> script_01: 1 file
#> /tmp/RtmpjOtcTs/my_scripts/script_01
#> 
#> script_02: 1 file
#> /tmp/RtmpjOtcTs/my_scripts/script_02
#> 
#> Summary: 2 total files saved across 2 URLs