[R] Using Rvest to scrape pages

[Tiffany Adekola]

Dear All,

I am just learning how to use R programming. I want to extract reviews
from a page and loop till I extract for all pages:

#specify the first page URL
fpURL <- 'https://wordpress.org/support/plugin/easyrecipe/reviews/'

#read the HTML contents in the first page URL
contentfpURL <- read_html(fpURL)

#identify the anchor tags in the first page URL
fpAnchors <- html_nodes(contentfpURL, css='a.bbp-topic-permalink')

#extract the HREF attribute value of each anchor tag
fpHREF <- html_attr(fpAnchors, 'href')

#create empty lists to store titles & contents found in the HREF
attribute value of each anchor tag
titles = c()
contents = c()

#loop the following actions for each HREF found firstpage
for (u in fpHREF) {

   #read the HTML content of the review page
   fpURL = read_html(u)

  #identify the title anchor and read the title text
  fpreviewT = html_text(html_nodes(fpURL, css='h1.page-title'))

  #identify the content anchor and read the content text
  fpreviewC = html_text(html_nodes(fpURL, css='div.bbp-topic-content'))

  #store the review titles and contents in the previous lists
  titles = c(titles, fpreviewT)
  contents = c(contents, fpreviewC)
}
#identify the anchor tag pointing to the next summary page
npAnchor <- html_text(html_node(contentfpURL, css='a.next page-numbers'))

#extract the HREF attribute value of the anchor tag pointing to the
next summary page
npHREF <- html_attr(npAnchor, 'href')

#loop the following actions for every next summary page HREF attribute
for (u in npHREF) {

  #specify the URL of the summary page
  spURL <- read_html('npHREF')

  #identify all the anchor tags on that summary page
  spAnchors <- html_nodes(spURL, css='a.bbp-topic-permalink')

  #extract the HREF attribute value of each anchor tag
  spHREF <- html_attr(spAnchors, 'href')

  #loop the following actions for each HREF found on that summarypage

   for (u in fpHREF) {
     #read the HTML contents of the review page
     spURL = read_html(u)

      #identify the title anchor and read the title text
      spreviewT = html_text(html_nodes(spURL, css='h1.page-title'))

      #identify the content anchor and read the content text
      spreviewC = html_text(html_nodes(spURL, css='div.bbp-topic-content'))

      #store the review titles and contents in the previous lists
      titles = c(titles, spreviewT)
      contents = c(contents, spreviewC)
      }
}

I got stuck at the step to extract the HREF attribute value of the
anchor tag pointing to the next summary page with the error: Error in
UseMethod("xml_attr") :
  no applicable method for 'xml_attr' applied to an object of class "character"

 I will appreciate any help with this task.
Thanks in advance.

---Tiffany