问题
I am trying to use the following code to get posts from a page on Facebook. I get an error even though the query works when I type it in a browser. This is the error I get:
WWW-Authenticate: OAuth "Facebook Platform" "invalid_request" "Unknown path components:
Any thoughts are greatly appreciated!
# go to 'https://developers.facebook.com/tools/explorer' to get your access token
access_token <- "### token ###"
require(RCurl)
require(rjson)
cafile <- system.file("CurlSSL", "cacert.pem", package = "RCurl")
options(RCurlOptions = list(verbose = TRUE, followlocation = TRUE, timeout = 100, useragent = "R"))
# set the curl options
curl <- getCurlHandle()
options(RCurlOptions = list(capath = system.file("CurlSSL", "cacert.pem",
package = "RCurl"),
ssl.verifypeer = FALSE, verbose = TRUE, cookiejar = 'my_cookies.txt',
cookiefile = 'my_cookies.txt', followlocation = TRUE,
useragent = 'Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.3) Gecko/20070309 Firefox/2.0.0.3'))
curlSetOpt(.opts = list(proxy = 'proxyserver:port'), curl = curl)
# Facebook json function copied from original (Romain Francois) post
facebook <- function( path = "me", access_token, options){
if( !missing(options) ){
options <- sprintf( "?%s", paste( names(options), "=", unlist(options), collapse = "&", sep = "" ) )
} else {
options <- ""
}
data <- getURL( sprintf( "https://graph.facebook.com/%s%s&access_token=%s", path, options, access_token ) )
fromJSON( data )
}
### TED FACEBOOK PAGE
# http://www.facebook.com/TED
# TED's Facebook ID 29092950651 can be found on http://graph.facebook.com/TED
ted <- list()
i<-0
next.path <- "29092950651/posts"
# download all TED posts
while(length(next.path)!=0) {
i<-i+1
ted[[i]] <- facebook( path=next.path , access_token=access_token)
next.path <- sub("https://graph.facebook.com/","",ted[[i]]$paging$'next')
}
ted[[i]] <- NULL
# parse just video links posted by TED
parse.count.ted <- function(x)
if (x$type=="link" & x$from$id=="29092950651") x$likes$count else NA
parse.link.ted <- function(x)
if (x$type=="link" & x$from$id=="29092950651") x$link else NA
ted.counts <- unlist(sapply(ted, parse.master, f=parse.count.ted))
ted.links <- unlist(sapply(ted, parse.master, f=parse.link.ted))
# see three most popular talks
ted.links[order(ted.counts,decreasing=TRUE)][1:3]
回答1:
This might be a problem of how the URL is being formatted. If the options
argument is not specified, the resulting URL would look like: /me/photos&access_token=...
. Here, the path would be /me/photos&access_token
which probably is not a valid URL component as per Facebook API.
I think the following changes to the facebook
function would fix this:
require(RCurl)
require(rjson)
facebook <- function( path = "me", access_token = token, options){
if( !missing(options) ){
options <- sprintf(
"?%s&",
paste(
names(options), "=", unlist(options),
collapse = "&", sep = ""
)
)
} else {
options <- "?"
}
urlTemplate <- "https://graph.facebook.com/%s%saccess_token=%s"
data <- getURL(
sprintf(
urlTemplate,
path,
options,
access_token
)
)
fromJSON( data )
}
Now, even if the options
argument is missing, the resulting URL would look like: /me/photos?access_token=...
.
来源:https://stackoverflow.com/questions/15046111/how-to-get-most-popular-facebook-post-in-r