undoHistory: Undo/Redo History Buttons

In fmmattioni/whippr: Tools for Manipulating Gas Exchange Data

Undo/Redo History Buttons

Description

This is a simple Shiny module for undo/redo history. The Shiny module accepts an arbitrary reactive data value. Changes in the state of this reactive value are tracked and added to the user's history. The user can then repeatedly undo and redo to walk through this stack. The module returns the current selected value of the reactive from this historical stack, or NULL when the app state was changed by the user. Because this reactive can hold arbitrary data about the state of the Shiny app, it is up to the app developer to use the returned current value to update the Shiny apps' inputs and UI elements.

Usage

undoHistory(id, value, value_debounce_rate = 500)

Arguments

id	The module id
value	The reactive expression with the values should be saved for the user's history. This expression can contain arbitrary data and be of any structure as long as it returns a single value (or list). Each change in this value is stored, so the module may not work well for storing large data sets.
value_debounce_rate	Debounce rate in milliseconds for the value reactive expression. To avoid saving spurious changes in value, the expression is debounced. See shiny::debounce() for more information.

Value

The undoHistory() module returns the currently selected history item as the user moves through the stack, or NULL if the last update was the result of user input. The returned value has the same structure as the reactive value passed to undoHistory().

fmmattioni/whippr documentation built on Feb. 23, 2024, 11:20 a.m.