### tryWithWarnings.R ---
#----------------------------------------------------------------------
## author: Brice Ozenne
## created: aug 29 2017 (09:52)
## Version:
## last-updated: feb 5 2018 (16:07)
## By: Brice Ozenne
## Update #: 20
#----------------------------------------------------------------------
##
### Commentary:
##
### Change Log:
#----------------------------------------------------------------------
##
### Code:
##' @title Run an Expression and Catch Warnings and Errors
##' @description Similar to \code{try} but also returns warnings.
##'
##' @param expr the line of code to be evaluated
##' @details
##' from https://stackoverflow.com/questions/4948361/how-do-i-save-warnings-and-errors-as-output-from-a-function
##'
##' @return A list containing:
##' \itemize{
##' \item value the result of the evaluation of the expression
##' \item warnings warning(s) generated during the evaluation of the expression
##' \item error error generated during the evaluation of the expression
##' }
##'
##' @examples
##' FctTest <- function(x){
##' return(log(x))
##' }
##' tryWithWarnings(FctTest(-1))
##' tryWithWarnings(FctTest(1))
##' tryWithWarnings(FctTest(xxxx))
##'
##' @export
tryWithWarnings <- function(expr) {
myWarnings <- NULL
myError <- NULL
FCT.envir <- environment()
wHandler <- function(w) {
assign("myWarnings", value = c(myWarnings, list(w)), envir = FCT.envir)
invokeRestart("muffleWarning")
}
eHandler <- function(e) {
assign("myError", value = e, envir = FCT.envir)
return(NULL)
}
val <- withCallingHandlers(tryCatch(expr, error = eHandler), warning = wHandler)
out <- list(value = val,
warnings = myWarnings,
error = myError)
return(out)
}
#----------------------------------------------------------------------
### tryWithWarnings.R ends here
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.