Download and Extract a Standalone Shinylive Application

Downloads and extracts a standalone Shinylive application from a URL. The function locates the application's app.json file, validates its structure, and extracts all application files to a local directory. Works with both R and Python Shinylive applications.

Usage

peek_standalone_shinylive_app(url, output_dir = "converted_shiny_app")

Arguments

url

Character string. URL pointing to either:

• A Shinylive app.json file directly

• A directory containing app.json

The function will automatically append "app.json" to directory URLs.

output_dir

Character string. Directory where the application files should be extracted. Defaults to "converted_shiny_app". Will be created if it doesn't exist. If the directory already exists, files may be overwritten.

Value

An object of class "standalone_shinylive_app" containing:

• List of extracted files and their contents

• Source URL of the application

• Output directory location

The object has a custom print method that displays:

• Application type (R or Python)

• Command to run the application

• List of extracted files by type

• File locations

File Structure

A valid Shinylive application should have an app.json file containing:

• At least one application file (e.g., app.R or app.py)

• Optional supporting files (e.g., data files, requirements.txt)

• File metadata including name, content, and type

Error Handling

The function will error with informative messages if:

• No app.json file is found at the URL

• The app.json file has invalid structure

• The app.json file cannot be downloaded

• Required application files are missing

See also

• find_shinylive_app_json() for app.json validation

• write_standalone_shinylive_app() for file extraction

• peek_shinylive_app() for a more general-purpose download function

Examples

if (FALSE) { # interactive()

# Download from a direct app.json URL
app <- peek_standalone_shinylive_app(
  "https://tutorials.thecoatlessprofessor.com/convert-shiny-app-r-shinylive/app.json"
)

# Download from a directory URL (app.json will be appended)
app <- peek_standalone_shinylive_app(
  "https://tutorials.thecoatlessprofessor.com/convert-shiny-app-r-shinylive/",
  output_dir = "my_local_app"
)

# Print shows how to run the application
print(app)
}