r - 如何抓取包含在 R 中链接的子链接中的文本？

Question

我正在尝试抓取这个网站。

如您所见，您可以单击一个主链接和一系列标题来访问文本。最后我想得到的是主链接的所有这些子链接中的文本。我对网络抓取不是很熟悉，所以环顾四周，我认为是这样的：

library(rvest)

x <- read_html("https://www.ecb.europa.eu/press/pressconf/html/index.en.html")

x1 <- html_nodes(x, ".doc-title a") # this using selector gadget

然而，这种尝试严重失败。有没有人可以帮助我？

非常感谢！

标签： rweb-scrapingrvestweb-scraping-language

Answer 1

可以获取初始页面的链接文本：

library(RSelenium)
library(rvest)
shell('docker run -d -p 4445:4444 selenium/standalone-firefox')
remDr <- remoteDriver(remoteServerAddr = "localhost", port = 4445L, browserName = "firefox")
remDr$open()
remDr$navigate("https://www.ecb.europa.eu/press/pressconf/html/index.en.html")

# This is useful to load all the page
for(i in 1 : 100)
{
  print(i)
  remDr$executeScript(paste0("scroll(0, ", i * 2000, ")"))
}

Sys.sleep(5)
html_Content <- remDr$getPageSource()[[1]]
html_Link <- str_extract_all(string = html_Content, pattern = "/press/pressconf/[^<]*html")[[1]]
html_Link_En <- html_Link[str_detect(html_Link, "\\.en\\.html")]
links_To_Remove <- c("/press/pressconf/html/index.en.html", "/press/pressconf/visual-mps/html/index.en.html" )
html_Link_En <- html_Link_En[!(html_Link_En %in% links_To_Remove)]
html_Link_En <- unique(html_Link_En)

# Extract text from first link
# It is possible to use a for loop to get the text of all links ...
html_Content <- read_html(paste0("https://www.ecb.europa.eu", html_Link_En[1]))
html_Content %>% html_text()