Hacker News new | ask | show | jobs
by MiddleEndian 3773 days ago
Offtopic:

Just posted a link to this on Facebook.

When I did, it auto-filled the headline as:

>Mars has 'widened its recall to 55 countries' - BBC News

and the teaser:

>The Netherlands spokesman for chocolate maker Mars says it has widened its recall of Mars and Snickers bars to 55 countries after bits of plastic are found in a product.

which don't match the actual article. Wonder what the deal with their caching is.

1 comments

Not really caching but as far as I remember there are HTML Open Graph tags that Facebook checks for in order to fetch the title/description etc.

Check N°3 on this link https://developers.facebook.com/docs/sharing/best-practices

And AFAIK the caching will run for about 30 days unless you clear it manually or through the API. Might be different for major sites.
Yeah, it caches the preview.

As mentioned in that doc, you can use the URL Debugger[1] to see the Open Graph data and even clear the cache.

I cleared the cache for the OP's BBC URL, try sharing it again and see what info you get.

[1] https://developers.facebook.com/tools/debug/

Good to know. I wonder how those ended up differing.
I assume what you saw was the BBC's title and summary at the time it was first shared (and thus cached) on Facebook. They've since edited it but FB keeps the cached version since the URI hasn't changed.