Decorator - Download

: If the function returns a string, it is treated as a path to an existing file on disk.

: The decorated function executes when a user clicks a specific download button or link in the UI. Return Types : Download Decorator

: Modern download decorators typically support both synchronous and async functions to prevent UI freezing during large file generations. Related Tools for Report Generation : If the function returns a string, it

The "Download Decorator" is a functional programming pattern, primarily used in web frameworks like , to manage file downloads by wrapping a data-generating function with the necessary handling logic . Core Functionality: @render.download Related Tools for Report Generation The "Download Decorator"

: For temporary files or large data, the function can yield strings or bytestrings, allowing the app to clean up resources after the download completes.

: Using decorators allows core business logic (e.g., calculate_sales() ) to remain clean, while the decorator handles logging, execution timing, or formatting the output into a downloadable file.

In the Shiny for Python framework, the @render.download decorator registers a function to handle a user-initiated download.