Assert that x is reactive — assert_reactive • assertions

Assert that x is reactive

Usage

assert_reactive(x, msg = NULL, call = rlang::caller_env(), arg_name = NULL)

Arguments

x: An object
msg: A character string containing the error message to display if x is not reactive
call: Only relevant when pooling assertions into multi-assertion helper functions. See cli_abort for details.
arg_name: Advanced use only. Name of the argument passed (default: NULL, will automatically extract arg_name).

Value

invisible(TRUE) if x is a reactive, otherwise aborts with the error message specified by msg

Examples

try({
# Assert that a variable is reactive
x <- shiny::reactive(1)
assert_reactive(x)  # does nothing

# Assert that a variable is not a list
x <- 1
assert_reactive(x)  # stops execution and prints an error message
})
#> Error in eval(expr, envir) : 
#>   'x' must be a reactive, not a numeric