Write File Content in a Shinylive App to Disk — write_file

Writes file content extracted from Shinylive applications to disk, handling both text and binary content appropriately. Creates any necessary parent directories and ensures proper encoding of content. For binary files, automatically decodes the base64-encoded content before writing.

Usage

write_file_content(content, file_path, type = "text")

Arguments

content: Character string containing the file content. For binary files, this should be base64-encoded content. For text files, this should be the raw text content.
file_path: Character string specifying the path where the file should be written. Parent directories will be created if they don't exist.
type: Character string specifying the file type, either "text" (default) or "binary". Binary files are assumed to be base64 encoded, as this is the standard format for binary content in Shinylive applications.

Value

Invisible NULL, called for its side effect of writing a file to disk.

Details

The function handles two types of content:

Text files (type = "text"):
- Content is converted to UTF-8 encoding using enc2utf8()
- Written using writeLines() with useBytes = TRUE
Binary files (type = "binary"):
- Content is decoded from base64 using jsonlite::base64_dec()
- Written as raw binary data using writeBin()

Parent directories in the file path are automatically created if they don't exist using fs::dir_create() with recurse = TRUE.

Examples

# Writing a text file
write_file_content(
  content = "library(shiny)\n\nui <- fluidPage()",
  file_path = "app/app.R",
  type = "text"
)

# Write base64 encoded image
b64img <- paste0(
  "iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAA",
  "DUlEQVR42mP8z8BQDwAEhQGAhKmMIQAAAABJRU5ErkJggg=="
)
write_file_content(b64img, "test.png", type = "binary")