On my website, I just added links to discuss posts on Facebook; you can see such a link at http://jonathanscorner.com/steel/ . The link redirects to https://www.facebook.com/pages/CJS-Hayward/9506801167, which lets people post but is initially empty.
I would like, if possible, to create a link that prepopulates the text of the comment to include the title and URL on my site. So someone who clicked on that link would have a posting that is prepopulated, '''I just finished "Within the Steel Orb" at http://JonathansCorner.com/steel/. '''
Is there some URL parameter I can use ('''...?text=I%20just%20finished...''') or other interface to prepopulate a comment in a JavaScript-generated link?
Thanks,
Short answer, you can't. Even with the feed dialog you can't prepopulate the comment area with some pre-defined text. What you can do is, using the feed dialog making people write their comments, and the connection of that feed redirects to your website.
The only problem is that this feed dialog would appear on the users feed an not on your page wall.
Another way, and this is the best option in my opinion, add the comments social plugin to your site, this way people would discuss that article on your page and every time they comment using this social plugin, the comments would appear on their facebook wall making their friends curious about that and maybe visit your site.
You can read more about that here: https://developers.facebook.com/docs/reference/plugins/comments/