We used the link:
http://www.facebook.com/sharer.php?u=[shared URL]
...to share a particular page. However, Facebook Sharer uses the cached version of the images and the title. Is there a way to quickly clear the Facebook cache or how long do we have to wait until the data gets updated?
I placed <link rel='image_src' href='[preview image]' />
in between the tags.
I found a solution to my problem. You could go to this site:
https://developers.facebook.com/tools/debug
...then put in the URL of the page you want to share, and click "debug". It will automatically extract all the info on your meta tags and also clear the cache.
Use api Is there an API to force Facebook to scrape a page again?
$furl = 'https://graph.facebook.com';
$ch = curl_init();
curl_setopt( $ch, CURLOPT_URL, $furl );
curl_setopt( $ch, CURLOPT_RETURNTRANSFER, true );
curl_setopt( $ch, CURLOPT_POST, true );
$params = array(
'id' => '<update_url>',
'scrape' => true );
$data = http_build_query( $params );
curl_setopt( $ch, CURLOPT_POSTFIELDS, $data );
curl_exec( $ch );
$httpCode = curl_getinfo( $ch, CURLINFO_HTTP_CODE );
Facebook treats each url as unique and caches the page based on that url, so if you want to share the latest url the simplest solution is to add a query string with the url being shared. In simple words just add ?v=1 at the end of the url. Any number can be used in place of 1.
Hat tip: Umair Jabbar
I thing these two links have a wide discussion on your problem related stuff. fb:ref clear cashes by calling
fbml.refreshRefUrl
like this
<tt>fbml.refreshRefUrl("http://www.mysite.com/someurl.php")
You can study the related stuff from here fb:ref. I hope it will work for you
The page to do this is at https://developers.facebook.com/tools/debug/ and has changed slightly since some of the other answers.
Paste your URL in there and hit "Debug". Then hit the "Fetch new scrape information" button under the URL text field and you should be all set. It'll pull the fresh meta tags from your page, but they'll still cache so keep in mind you'll need to do this whenever you change them. This is really critical if you are playing with the meta tags to get FB Shared URLs to format the way you want them to inside of facebook.
This answer is intended for developers.
Clearing the cache means that new shares of this webpage will show the new content which is provided in the OG tags. But only if the URL that you are working on has less than 50 interactions (likes + shares). It will also not affect old links to this webpage which have already been posted on Facebook. Only when sharing the URL on Facebook again will the way that Facebook shows the link be updated.
catandmouse's answer is correct but you can also make Facebook clear the OG (OpenGraph) cache by sending a post request to graph.facebook.com (works for both http and https as of the writing of this answer). You do not need an access token.
A post request to graph.facebook.com may look as follows:
POST / HTTP/1.1
Content-Type: application/x-www-form-urlencoded
Host: graph.facebook.com
Content-Length: 63
Accept-Encoding: gzip
User-Agent: Mojolicious (Perl)
id=<url_encoded_url>&scrape=true
In Perl, you can use the following code where the library Mojo::UserAgent is used to send and receive HTTP requests:
sub _clear_og_cache_on_facebook {
my $fburl = "http://graph.facebook.com";
my $ua = Mojo::UserAgent->new;
my $clearurl = <the url you want Facebook to forget>;
my $post_body = {id => $clearurl, scrape => 'true'};
my $res = $ua->post($fburl => form => $post_body)->res;
my $code = $res->code;
unless ($code eq '200') {
Log->warn("Clearing cached OG data for $clearurl failed with code $code.");
}
}
}
Sending this post request through the terminal can be done with the following command:
curl -F id="<URL>" -F scrape=true graph.facebook.com
Append a ?v=random_string to the url. If you are using this idea with Facebook share, make sure that the og:url param in the response matches the url you are sharing. This will work with google plus too.
For Facebook, you can also force recrawl by making a post request to https://graph.facebook.com
{id: url,
scrape: true}
I just posted a simple solution that takes 5 seconds here on a related post here - Facebook debugger: Clear whole site cache
short answer... change your permalinks on a worpdress site in the permalinks settings to a custom one. I just added an underscore.
/_%postname%/
then facebook scrapes them all as new urls, new posts.
if you are using wordpress with a cache plugin, make sure you clear all your caches. Also make sure the image you are using has the recommended facebook size: 1200(w) x 630(h) or 600 x 315.
If you used managed wordpress or caching plugins, you have to CLEAR YOUR CACHE before the facebook debugger tool can fetch new info!
I've been pulling my hair out for weeks figuring out why changes I made wouldn't show up in facebook debugger for 24 hours!!!! The fix is I have to go into my wordpress dashboard, click the godaddy icon on the top, and click "flush cache." I think many managed wordpress hosters have a cache to figure out how to clear it and you'll be golden.
来源:https://stackoverflow.com/questions/5256114/how-to-clear-facebook-sharer-cache