I looked around, but can’t seem to find an answer.
I tried sharing some topics from this forum to Facebook as a test, but none of them show the image. Type of errors I get:
Provided og:image URL
https://d11a6trkgmumsb.cloudfront.net/optimized/4X/e/0/4/e04203d665f3ff3540361fdeedb76df8cf37df9b_2_1024x767.jpeg could not be processed as an image.
It may be corrupted or may have an invalid format.
Could not resolve the hostname into a valid IP address.
Anyone lucky enough to share topics and Facebook showing the image properly?
To my knowledge, Facebook “support” doesn’t even exist.
But this doesn’t seem to be a Facebook issue, because on my own Discourse installation, some images are shown, so I would just like to know what’s the process to make them work? Is the first image in the topic? If so, why would that topic from this very forum not work (along with others I tried), but for mine it did?
That’s the image URL to which you were referring in the OP.
The flow for this process is:
User posts the topic URL to Facebook
Facebook retrieves the topic URL and parses the opengraph tags
Facebook identifies the og:image URL
Facebook attempts to retrieve the og:image URL
Facebook resolves the URL’s hostname into an IP address
Facebook connects to the IP
Facebook retrieves the URL
If it’s trying to retrieve the URL https://d11a6trkgmumsb.cloudfront.net/optimized/4X/e/0/4/e04203d665f3ff3540361fdeedb76df8cf37df9b_2_1024x767.jpeg but gives the error Could not resolve the hostname into a valid IP address. Discourse is not in the path for that step of the process. It’s Facebook’s servers trying to resolve an Amazon Cloudfront hostname.
I was just wondering if something could be wrong with how Discourse was picking the images and setting the og:image. But yes, if my Discourse works (even though not 100% perfect), then maybe something is wrong with what you said.
So, my question still is: the image being picked is always the topmost image in the topic? Is it how Discourse it built? Or is it randomly picked? And are there any specific requirements for it to pick the image in terms of image dimensions, etc? Just want to make sure that when it comes to my own topics, if I want to include images, I format them properly.
Thank you so much for the tip. Didn’t know about it.
How about image dimensions? Any requirements? Or any image will be used, even if it gets distorted by being resized?
EDIT: I just noticed that this is a component… so I have to install the component in order to decide which image will be used by OpenGraph? I’m a bit confused now, sorry.
I’m not sure, but I think any image can be used, and resizing is up to the consumer. For example, I just tested a small image on try, let’s see its Onebox:
It is a bit confusing indeed, the |thumbnail logic is all on core, the theme component just requests that core generates additional thumbnail sizes, and uses them on the topic list. It happened to be the only topic (that I know of) with that piece of information, hence the quote.
Thank you for clarifying. I am definitely installing this component, because it’s a feature I really want to use on some categories. I also checked a similar component, the Topic Cards. This one seems to have its own strengths as well.