R help - Aug 2018 - How deep into function calls does trycatch() work

Hi All:

I am using another package in a project I have. Because of that,  I have no
control on how that package behaves or what it returns.  This package has a
function foo()  that calls httr::GET(),  and if it gets an error from
httr::GET() it calls the following routine:


err_handle2 <- function(x) {
  if (x$status_code > 201) {
    tt <- content(x, "text")
    mssg <- xml_text(xml_find_all(read_html(tt), "//h1"))
    stop(paste0(mssg, collapse = "\n\n"), call. = FALSE)
  }
}

My question is if I embed my call to foo() in try...catch will that override the
stop() call or am I a goner, or is there another way to override it,  given that
I can't change the code to err_handle2().

Thanks,

-Roy


**********************
"The contents of this message do not reflect any position of the U.S.
Government or NOAA."
**********************
Roy Mendelssohn
Supervisory Operations Research Analyst
NOAA/NMFS
Environmental Research Division
Southwest Fisheries Science Center
***Note new street address***
110 McAllister Way
Santa Cruz, CA 95060
Phone: (831)-420-3666
Fax: (831) 420-3980
e-mail: Roy.Mendelssohn at noaa.gov www: http://www.pfeg.noaa.gov/

"Old age and treachery will overcome youth and skill."
"From those who have been given much, much will be expected" 
"the arc of the moral universe is long, but it bends toward justice"
-MLK Jr.

AFAIK a try or tryCatch will intercept the error thrown by stop(). Why
not try it and see if it works?

Peter
On Thu, Aug 16, 2018 at 1:05 PM Roy Mendelssohn - NOAA Federal via
R-help <r-help at r-project.org> wrote:
>
> Hi All:
>
> I am using another package in a project I have. Because of that,  I have no
control on how that package behaves or what it returns.  This package has a
function foo()  that calls httr::GET(),  and if it gets an error from
httr::GET() it calls the following routine:
>
>
> err_handle2 <- function(x) {
>   if (x$status_code > 201) {
>     tt <- content(x, "text")
>     mssg <- xml_text(xml_find_all(read_html(tt), "//h1"))
>     stop(paste0(mssg, collapse = "\n\n"), call. = FALSE)
>   }
> }
>
> My question is if I embed my call to foo() in try...catch will that
override the stop() call or am I a goner, or is there another way to override
it,  given that I can't change the code to err_handle2().
>
> Thanks,
>
> -Roy
>
>
> **********************
> "The contents of this message do not reflect any position of the U.S.
Government or NOAA."
> **********************
> Roy Mendelssohn
> Supervisory Operations Research Analyst
> NOAA/NMFS
> Environmental Research Division
> Southwest Fisheries Science Center
> ***Note new street address***
> 110 McAllister Way
> Santa Cruz, CA 95060
> Phone: (831)-420-3666
> Fax: (831) 420-3980
> e-mail: Roy.Mendelssohn at noaa.gov www: http://www.pfeg.noaa.gov/
>
> "Old age and treachery will overcome youth and skill."
> "From those who have been given much, much will be expected"
> "the arc of the moral universe is long, but it bends toward
justice" -MLK Jr.
>
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.