How can I read and parse the contents of a webpage in R
I'd like to read the contents of a URL (e.q., http://www.haaretz.com/) in R. I am wondering how I can do it
Answer
Not really sure how you want to process that page, because it's really messy. As we re-learned in this famous stackoverflow question, it's not a good idea to do regex on html, so you will definitely want to parse this with the XML package.
Here's an example to get you started:
require(RCurl)
require(XML)
webpage <- getURL("http://www.haaretz.com/")
webpage <- readLines(tc <- textConnection(webpage)); close(tc)
pagetree <- htmlTreeParse(webpage, error=function(...){}, useInternalNodes = TRUE)
# parse the tree by tables
x <- xpathSApply(pagetree, "//*/table", xmlValue)
# do some clean up with regular expressions
x <- unlist(strsplit(x, "\n"))
x <- gsub("\t","",x)
x <- sub("^[[:space:]]*(.*?)[[:space:]]*$", "\\1", x, perl=TRUE)
x <- x[!(x %in% c("", "|"))]
This results in a character vector of mostly just webpage text (along with some javascript):
> head(x)
[1] "Subscribe to Print Edition" "Fri., December 04, 2009 Kislev 17, 5770" "Israel Time:Â 16:48Â (EST+7)"
[4] "Â Â Make Haaretz your homepage" "/*check the search form*/" "function chkSearch()"