Wsrtjtyk

I'm using a loop function to get some urls inside a df and do some validation, like this:

for (i in 1:nrow(df)) {

webpage <- read_html(as.character(df[i,1]))

Sys.sleep(0.025)

validation <- webpage %>% html_nodes("a") %>% html_attr('href')

if (length(grep("bitstream",validation)>0)) {

  df$text[[i]] <- "Valid"}

else {

  df$text[[i]] <- "Invalid"}

}

The problem is that if and url is broken i get an error message like this:

Error in open.connection(x, "rb") : HTTP error 500

and the loop stops.
Is there a way to set another if condition so it doesn't stop?

I've used tryCatch as @hrbrmstr suggested in the comments, but added a little thing so it would work better.
Using an valid_url checking condition among an next statement for the loop to start over again.

for (i in 1:nrow(df)) {



valid_url <- TRUE



tryCatch({webpage <- read_html(as.character(df[i,1]))}, error=function(e) url_valido<<-FALSE)



if (!valid_url){ cat("14")  

cat(paste(i," - Invalid URL","nStatus: ",

          percent(i/nrow(df)),sep=""))

df$text[[i]] <- "Invalid URL"



next}



Sys.sleep(0.025)

teste <- webpage %>% html_nodes("a") %>% html_attr('href')

if (length(grep("bitstream",teste)>0)) {



  df$texto[[i]] <- "Completo"}

else {

  df$texto[[i]] <- "Incompleto"}

cat("14")  

cat(paste(i," - ",df$texto[[i]],"nStatus: ",

            percent(i/nrow(df)),sep=""))

}