How to make sure that the user made a repost on the social network from the site page?

Question

PHP

For example facebook.
The site has a "Share" button, by clicking on it, a facebook window opens in which the user can share the site page on his facebook wall. But clicking on the button on the site itself does not guarantee that the user has made a repost, because the confirmation to share the post occurs on the side of Facebook. Yes, and the user can also remove the repost from his wall.
Tell me, is there any way to make sure that the user has created a repost and there is a repost on the wall? Not necessarily in detail, at the level of an algorithm or hints.

Answer 1

If you really really want to, then, as Greg Popov correctly wrote, we ask the user for the right to view his posts ( user_posts permission ), look , check.
In practice, you can catch negative feedback from people, because no one likes extra rights
+ processing becomes much more complicated (do not forget that the user can selectively disable application rights)
PS Taking into account the fact that nothing prevents the user from deleting a post at any time after publication - how then technically it makes no sense to control it all. Come up with marketing incentives to really do share.