`Onebox.preview` can return 0-to-n errors, where the errors are missing OpenGraph attributes (e.g. title, description, image, etc.). If any of these attributes are missing, we construct an error message and attach it to the Oneboxer preview HTML. The error message is something like:
“Sorry, we were unable to generate a preview for this web page, because the following oEmbed / OpenGraph tags could not be found: description, image”
However, if the only missing tag is `image` we don’t need to display the error, as we have enough other data (title, description, etc.) to construct a useful/complete Onebox.
* FEATURE: display error if Oneboxing fails due to HTTP error
- display warning if onebox URL is unresolvable
- display warning if attributes are missing
* FEATURE: Use new Instagram oEmbed endpoint if access token is configured
Instagram requires an Access Token to access their oEmbed endpoint. The requirements (from https://developers.facebook.com/docs/instagram/oembed/) are as follows:
- a Facebook Developer account, which you can create at developers.facebook.com
- a registered Facebook app
- the oEmbed Product added to the app
- an Access Token
- The Facebook app must be in Live Mode
The generated Access Token, once added to SiteSetting.facebook_app_access_token, will be passed to onebox. Onebox can then use this token to access the oEmbed endpoint to generate a onebox for Instagram.
* DEV: update user agent string
* DEV: don’t do HEAD requests against news.yahoo.com
* DEV: Bump onebox version from 2.1.5 to 2.1.6
* DEV: Avoid re-reading templates
* DEV: Tweaks to onebox mustache templates
* DEV: simplified error message for missing onebox data
* Apply suggestions from code review
Co-authored-by: Gerhard Schlager <mail@gerhard-schlager.at>
