Hello,
I need to prepare a form.
Admins needs to enter post title, attach thumbnail image,
select taxonomy. Based on selected taxonomy,
I need to make a WP_Query and on submit, it attached the post ids returned from WP_Query to the post_meta.
Following is my github gist for the form.
https://gist.github.com/vineettalwar/855a93b45b16163b31bb54af0a2b8dc3
I need to read selected taxonomy term id, then pass that term id to on_submit_query function (written at the end of the file.). it shall return post ids from that WP_Query and I need to simply update that id array to newly created post at a post meta key post_ids_key

1) Could you please tell me how can I achieve that ?
2) Every time a new post is created, is there any way it can be checked, if post exists then, update the post only in piklist.