Question

How can I use my custom image as thumbnail for facebook sharer? cause I want to share other image for it. Also I would like to add some functions in it like whenever the user was sharing, the thumbnail would show the flag from where he/she was. Or is it even possible for me to do that? Thanks

Answer 1

You have to add a few meta tags to the page you’re sharing, kinda like this:

<link rel="image_src" type="image/jpeg" href="IMAGE_URL_GOES_HERE"/>    
<meta itemprop="image" content="IMAGE_URL_GOES_HERE"/>
<meta property="og:image" content="IMAGE_URL_GOES_HERE"/>

Alternatively, a better way to achieve the same result is using the FB.ui function from the Javascript SDK:

var link = {};
link.method = 'feed';
link.link = url;
link.picture = imageURL;
link.name = title;
link.caption = caption;
link.description = description;
FB.ui(link,callback);

This way, you have a lot more control over what gets shared.

If you’re limited on JS usage, a direct link is also available instead of FB.ui:

http://www.facebook.com/dialog/feed?
  app_id=123050457758183&
  link=http://developers.facebook.com/docs/reference/dialogs/&
  picture=http://fbrell.com/f8.jpg&
  name=Facebook%20Dialogs&
  caption=Reference%20Documentation&
  description=Using%20Dialogs%20to%20interact%20with%20users.&
  redirect_uri=http://www.example.com/response

More info here: http://developers.facebook.com/docs/reference/dialogs/feed/