Error: XML Content does not seem to be XML | R 3.1.0

I am trying to get this XML file, but am unable to. I checked the other solutions in the same topic, but I couldn't understand. I am a R newbie.

> library(XML)
> fileURL <- "https://d396qusza40orc.cloudfront.net/getdata%2Fdata%2Frestaurants.xml"
> doc <- xmlTreeParse(fileURL,useInternal=TRUE)

Error: XML content does not seem to be XML: 'https://d396qusza40orc.cloudfront.net/getdata%2Fdata%2Frestaurants.xml';

Can you please help?

Remove the s from https

library(XML)

fileURL<-"https://d396qusza40orc.cloudfront.net/getdata%2Fdata%2Frestaurants.xml"
doc <- xmlTreeParse(sub("s", "", fileURL), useInternal = TRUE)
class(doc)
## [1] "XMLInternalDocument" "XMLAbstractDocument"

You can use RCurl to fetch the content and then XML seems to be able to handle it

library(XML)
library(RCurl)
fileURL <- "https://d396qusza40orc.cloudfront.net/getdata%2Fdata%2Frestaurants.xml"
xData <- getURL(fileURL)
doc <- xmlParse(xData)

xmlTreeParse does not support https.

You can load the data with getURL (from RCurl) and then parse it.

Answer is at http://www.omegahat.net/RCurl/installed/RCurl/html/getURL.html. Key point is to use ssl.verifyPeer=FALSE with getURL if certificate error is shown.

library (RCurl)
library (XML)
curlVersion()$features
curlVersion()$protocol
##These should show ssl and https. I can see these on windows 8.1 at least. 
##It may differ on other OSes.

temp <- getURL("https://d396qusza40orc.cloudfront.net/getdata%2Fdata%2Frestaurants.xml", ssl.verifyPeer=FALSE)
DFX <- xmlTreeParse(temp,useInternal = TRUE)

If ssl or https capability is not shown by libcurl functions, check https://stackoverflow.com/questions/6736895/using-rcurl-with-https.

Using download.file avoids introducing another dependency. The following function returns the output of XML::xmlParse also when the URL starts with https. It caches the file to a temporary directory so that it will be downloaded only once if this function is called many times during an R session.

xml_parse <- function(xml_url){
    # Temporary copy of the xml file, valid for this R session
    xml_temp_file <- file.path(tempdir(), basename(xml_url))
    if (!file.exists(xml_temp_file)){
        print(sprintf("Downloading to %s.", xml_temp_file))
        download.file(xml_url, xml_temp_file)
    }
    return(XML::xmlParse(xml_temp_file))
}

# Example
xml_content = xml_parse("https://d396qusza40orc.cloudfront.net/getdata%2Fdata%2Frestaurants.xml")