Suppress warning message in R console of shiny

Question

We developed a shiny application. It was showing some warning messages, we never bothered it, because the application is working fine. But, we can't distribute the application with warning message appearing in the console. Now my question is, how to suppress the warning message in R console, when shiny application is running.

Answer 1

Insert this in your ui script.

tags$style(type="text/css",
         ".shiny-output-error { visibility: hidden; }",
         ".shiny-output-error:before { visibility: hidden; }"
)

Answer 2

You actually have two suppress functions via R that work differently for you:

suppressMessages() evaluates its expression in a context that ignores all ‘simple’ diagnostic messages." See ?suppressMessages.

• suppressWarnings() evaluates its expression in a context that ignores all warnings. See ?suppressWarnings.

Examples:

f <- function(a) { a ; warning("This is a warning") ; message("This is a message not a warning")}

> f(1)
This is a message not a warning
Warning message:
In f(1) : This is a warning

> suppressWarnings(f(1))
This is a message not a warning

> suppressMessages(f(1))
Warning message:
In f(1) : This is a warning

Answer 3

Wrapping suppressWarnings around your code should work. See ?suppressWarnings. You need to do something like:

atest <- function(n) {warning("a warning"); return(n+1)}
atest(1)
#[1] 2
#Warning message:
#In atest(2) : a warning

suppressWarnings(atest(1))
#[1] 2

But I guess that the better solution is to actually deal with the warning and not just ignore it.