问题
I'm trying to implement Facebook's OpenGRaph protocol on my product pages.
On each page i have this above the head section:
<html xmlns="http://www.w3.org/1999/xhtml" xmlns:og="http://ogp.me/ns#" xmlns:fb="http://www.facebook.com/2008/fbml">
Then within the head section i have:
<meta property="og:title" content="This Page Title"/>
<meta property="og:type" content="product"/>
<meta property="og:url" content="http://www.mywebaddress.com"/>
<meta property="og:image" content="http://www.myimage.jpg"/>
<meta property="og:site_name" content="My Site Name"/>
<meta property="fb:admins" content="10101010101"/>
<meta property="og:email" content="hello@mywebaddress.com"/>
<meta property="og:description" content="Description of my product."/>
I then have a 'like' button with this code:
<script>(function(d, s, id) {
var js, fjs = d.getElementsByTagName(s)[0];
if (d.getElementById(id)) {return;}
js = d.createElement(s); js.id = id;
js.src = "//connect.facebook.net/en_US/all.js#xfbml=1";
fjs.parentNode.insertBefore(js, fjs);
}(document, 'script', 'facebook-jssdk'));</script>
<div class="fb-like" data-href="http://thispagesurl" data-send="true" data-width="350" data-show-faces="false"></div>
To my eye, everything seems to replicate what can be found on the Facebook Developers page but when i 'like', Facebook is seemingly only picking up on the page title and general info.
I have tried to 'debug' the page using their Object debugger, and i get these warnings:
Inferred Property The og:url property should be explicitly provided, even if a value can be inferred from other tags.
Inferred Property The og:title property should be explicitly provided, even if a value can be inferred from other tags.
Inferred Property The og:image property should be explicitly provided, even if a value can be inferred from other tags.
Inferred Property The og:locale property should be explicitly provided, even if a value can be inferred from other tags.
As far as i can tell, i have followed Facebook's instructions to the letter, but i have no joy. Can anyone point out if i'm doing anything wrong?
Thanks in advance, Dan
回答1:
Are those tags on 'http://www.mywebaddress.com'?
Bear in mind the linter will follow the og:url tag as this tag should point to the canonical URL of the piece of content - so if you have a page, e.g. 'http://mywebaddress.com/article1' with an og:url tag pointing to 'http://mywebaddress.com', Facebook will go there and read the tags there also.
Failing that, the most common reason i've seen for seemingly correct tags not being detected by the linter is user-agent detection returning different content to Facebook's crawler than the content you're seeing when you manually check
回答2:
You need a space after the final set of quote marks
<meta property="og:url" content="http://www.mywebaddress.com"/>
Should be..likes this one
<meta property="og:url" content="http://www.mywebaddress.com" />
回答3:
There is some confusion about tons of Facebook Tools and Documentation. So many people probably use the Sharing Debugger tool to check their OpenGraph markup: https://developers.facebook.com/tools/debug/sharing/
But it only retrieves the information about your site from the Facebook cache. This means that after you change the ogp-markup on your site, the Sharing Debugger will still be using the old cached data. Moreover, if there is no cached data on the Facebook server then the Sharing Debugger will show you the error: This URL hasn't been shared on Facebook before.
So, the solution is to use another tool – Open Graph Object Debugger: https://developers.facebook.com/tools/debug/og/object/
It allows you to Fetch new scrape information and refresh the Facebook cache:
Honestly, I don't know how to find this tool exploring the Tools & Support section of developers.facebook.com – I cannot find any links and mentions. I only have this tool in my bookmarks. That's Facebook :)
Use 'property'-attrs
I also noted that some developers use the name attribute instead of property. Many parsers probably will process such tags properly, but according to The Open Graph protocol, we should use property, not name:
<meta property="og:url" content="http://www.mywebaddress.com"/>
Use full URLs
The last recommendation is to specify full URLs. For example, Facebook complains when you use relative URL in og:image. So use the full one:
<meta property="og:image" content="http://www.mywebaddress.com/myimage.jpg"/>
回答4:
In case it helps anyone I had the same error. It turns out my page had not been scrapped by Facebook in awhile and it was an old error. There was a scrape again button on the page that fixed it.
回答5:
It might help some people who are struggling to get Facebook to read Open Graph nicely...
Have a look at the source code that is generated by browser using Firefox, Chrome or another desktop browser (many mobiles won't do view source) and make sure there is no blank lines before the doctype line or head tag... If there is Facebook will have a complete tantrum and throw it's toys out of the pram! (Best description!) Remove Blank Line - happy Facebook... took me about 1.5 - 2 hours to spot this!
来源：https://stackoverflow.com/questions/7869430/facebook-open-graph-error-inferred-property