I am running a php based website and having images on posts. The images are totally dynamic. Every time a user visits, the images keep changing. So, when a user shares the post on facebook, the og image shows cached image. Is there any way to fetch new data from url and clear the cache when a user shares the post?
Yes, it is possible. Just do a POST request (with cURL, for example) to the following URL:
POST Parameters with values:
Btw, it´s a very bad idea to rescrape whenever someone hits the Page. OG tags are meant to be static.