Just a simple question, I had facebook comments integrated in my page here:
http://www.bbcnepalidrama.com/main/node/3
Now I have changed the URL alias like this:
http://www.bbcnepalidrama.com/main/about
I have also set a 301 redirect in the old URL which redirects to the new one. The Question is how do I get the old comments in this URL? They are missing now.
I think, that these comments will be forever associated with that URL and since you've changed it, as far as FB is concerned you are pointing to a different URL.
you can specify the old URL as “canonical” with an og:url meta tag.
see the FAQ about this.
This sucks in Facebook comments. I've launched a site with Facebook comments integrated, without setting the URL, and now when I do, the comments doesn't show up.
Your case seems to be easy, since it seems you're using Drupal. You can install the token and token_filter modules, so you can add the facebook comments code to a block and use the appropriate token that will return the node id from the current page.
来源：https://stackoverflow.com/questions/8133406/facebook-social-plugin-comments-after-url-change