WordPress responds to the ajax request with readyState 1, 2, 3 before responding with 4
readyState= 1 this.status= 0 readyState= 2 this.status= 200 readyState= 3 this.status= 200 readyState= 4 this.status= 200
These are the responses I get, and in the end it finally responds with 4 and 200. My php function just echoes
"hello from php". I used
ob_clean() before echo and
wp_die() as per Codex recommendations because it said there may be unnecessary responses mixed in with ajax but still didn’t help at all.