Tried several sites (ie: Google Play) to test onebox by pasting URL but it only shows the link instead of the content. Other sites like Washing Post works fine. Tested the non working URL at Iframely URL Debugger - Open Graph, Twitter Cards, oEmbed and it displays fine.
Results from two different links at try.discourse.org - neither one has text before or after the URLs
edit: added third link which works
Couple notes there:
why would you expect Target to onebox? Does Target support OpenGraph, oEmbed, what does Iframely URL Debugger - Open Graph, Twitter Cards, oEmbed say?
I think the Play oneboxer needs some improvements, PRs welcome in this area. Pretty sure we only tested it with apps, not music or movies.
The oneboxer is open source too, if you can think of improvements please contribute PRs!
Target looked fine on iframely so decided to use that for the example
This is from iframely which also shows twitter cards correctly
Where are official docs for oneboxing located?
Note that unless a site is on the whitelist, it isn’t going to onebox – even if Iframely URL Debugger - Open Graph, Twitter Cards, oEmbed confirms that Open Graph / oEmbed support is there.
So you may need to edit the whitelist in Admin, Site Settings.
As for the Play oneboxer, I am sure it can be improved – or maybe we should just whitelist Play and let opengraph/oembed work their magics.