Scraping only the NEWEST blog post with rvest in R - r

Question

I'm using rvest to scrape the .txt files of a blog page, and I have a script that triggers every day, and scrapes the newest post. The base of that script is an lapply function that simply scrapes all of the posts, and I later sort out duplicates using Apache NiFi.
That's not an efficient way to sort duplicates, so I was wondering if there's a way to use the same script, and only scrape the newest posts?
The posts are labelled with numbers that count up, such as BLOG001, BLOG002, etc. I want to put a line of code that makes sure to scrape the newest posts (they may post several in any given day). How do I make sure that I only get BlOG002, and the next run only get BLOG003, and so on?
library(tidyverse)
library(rvest)
# URL set up
url <- "https://www.example-blog/posts.aspx"
page <- html_session(url, config(ssl_verifypeer = FALSE))
# Picking elements
links <- page %>%
html_nodes("td") %>%
html_nodes("a") %>%
html_attr("href")
# Function
out <- Map(function(ln) {
fun1 <- html_session(URLencode(
paste0("https://www.example-blog", ln)),
config(ssl_verifypeer = FALSE))
writeBin(fun1$response$content)
return(fun1$response$content)
}, links)

Answer 1

Assuming that all of the links you want start with 'BLOG' as in your post, and you only want to download the one with the maximum number each time the code is run. You could try something like this to achieve that.
library(tidyverse)
library(rvest)
# URL set up
url <- "https://www.example-blog/posts.aspx"
page <- html_session(url, config(ssl_verifypeer = FALSE))
# Picking elements
links <- page %>%
html_nodes("td") %>%
html_nodes("a") %>%
html_attr("href")
# Make sure only 'BLOG' links are checked
links <- links[substr(links, 1, 4) == 'BLOG']
# Get numeric value from link
blog.nums <- as.numeric(substr(links, 5, nchar(links)))
# Get the maximum link value
max.link <- links[which(blog.nums == max(blog.nums))]
fun1 <- html_session(URLencode(
paste0("https://www.example-blog", max.link)),
config(ssl_verifypeer = FALSE))
writeBin(fun1$response$content)