R Academy · Lesson

html_element() and html_text() Basics

Extract text, attributes, and table data from scraped pages.

read_html(): Loading a Page

read_html() is the entry point for rvest. Pass a URL or a raw HTML string. It returns an xml_document object representing the parsed DOM tree, ready for querying.

library(rvest)

# From a URL (requires internet connection)
# page <- read_html('https://books.toscrape.com')

# From a raw HTML string (great for testing)
page <- read_html('
  <html><body>
    <h1>Book Store</h1>
    <p class="desc">Over 1000 books!</p>
  </body></html>
')
class(page)  # 'xml_document' 'xml_node'

html_element() vs html_elements()

html_element() returns the first matching node (or NA if none found). html_elements() returns all matching nodes as a list. Use singular when you expect exactly one result, plural when scraping lists.

library(rvest)
page <- read_html('
  <ul>
    <li class="item">Apple</li>
    <li class="item">Banana</li>
    <li class="item">Cherry</li>
  </ul>
')
# Singular: gets first match
first_item <- html_element(page, '.item')
html_text2(first_item)  # 'Apple'

# Plural: gets all matches
all_items <- html_elements(page, '.item')
html_text2(all_items)  # c('Apple', 'Banana', 'Cherry')
length(all_items)  # 3

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