How to set title, img, and description on wall post made from facebook comments
I'm building a facebook iFrame application that uses facebook comments. When a user leaves a comment the default action is that this comment will be posted to their wall. The wall post is something along the lines of
UserX commented on example.com
# the comment text goes here
http://example.com
apps.facebook.com
You should be able to include an image, a description, and set the link to be the title of the page (where it says http://example.com above the apps.facebook.com), but I'm having no luck getting this to work.
I thought it would grab the information from my meta tags (as long as they included the appropriate 'og' tags), but that isn't working. Nor am I able to define values for title, url, image etc. in the same way that you can for normal wall posts.
Anyone have any idea how to get this working??
EDIT:
Here are t开发者_运维知识库he meta tags I currently am using.
<meta property="og:title" content="USERNAME'S PAGE" />
<meta property="og:type" content="website" />
<meta property="og:url" content="http://example.com"/>
<meta property="og:image" content="http://example.com/images/wall-post.png" />
<meta property="og:description" content="Some description goes here." />
Use URL Linter to Debug http://developers.facebook.com/tools/lint/
Make sure all meta tags are correct and if you've made some changes, it takes some time to update for facebook and here's a sample, this is a working version:
<!doctype html>
<html xmlns:og="http://ogp.me/ns#"
xmlns:fb="https://www.facebook.com/2008/fbml" lang="en">
<head>
<meta charset="utf-8">
<title>Facebook Comment Box Sample</title>
<meta property="og:title" content="YOUR-POST-TITLE"/>
<meta property="og:type" content="website"/>
<meta property="og:url" content="http://YOUR-SITE-URL"/>
<meta property="og:image" content="http://YOUR-IMAGE-URL"/>
<meta property="og:site_name" content="YOUR-SITE-TITLE"/>
<meta property="og:description" content="YOUR-DESCRIPTION"/>
<meta property="fb:admins" content="YOUR-USER-ID"/>
</head>
<body>
<h1>Facebook Comment Box:</h1>
<div id="fb-root"></div><script src="http://connect.facebook.net/en_US/all.js#xfbml=1"></script>
<fb:comments href="http://YOUR-SITE-URL" num_posts="10" width="500"></fb:comments>
</body>
</html>
OK, after a lot of stumbling around I figured this out.
My iFrame application requires facebook authentication before accessing the application (as I believe all facebook apps do). This means that the facebook crawlers were unable to crawl my homepage and pick up the og: meta tags.
To solve this I first had to figure out what the facebook crawler looks like. I logged the HTTP_USER_AGENT for all requests and then used the facebook URL Linter (http://developers.facebook.com/tools/lint/) to ping my site.
The facebook crawler identifies itself as "facebookexternalhit/1.1 (+http://www.facebook.com/externalhit_uatext.php)"
Once I had that I was able to just add a little conditional logic to let the crawler bypass authentication and access my site. I hope this helps others.
First I made sure I had all my meta properties set, then I just put my code in this:
if (strpos($_SERVER['HTTP_USER_AGENT'],"externalhit_uatext")<5)
{
}
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