Detect if a UI element has changed

Takes a UI element value and an older value and determines if it has been modified

Usage

has_changed(ui_val = NULL, old_val = NULL, init_value = c(""))

Arguments

ui_val

Current value from the UI.

old_val

Last value of of the element.

init_value

Default value for reading in UI data when it has not been defined.

Value

Boolean result of the comparison

Examples

changed_true  = has_changed(ui_val = "a", old_val = "")
changed_true
#> [1] TRUE
changed_false = has_changed(ui_val = "a", old_val = "a")
changed_false
#> [1] FALSE