Get user name inside AJAX success function - php

Question

I'm trying to display the username when an AJAX request is successful.
The problem that I'm running into is that the name remains blank.
Simplified code (removed if statements, checks, and other unrelated code)
wp_localize_script('follow-me-ajax', 'ajax_setting', array(
'ajax_url' => admin_url('admin-ajax.php'),
'ajax_nonce' => wp_create_nonce('km-ajax-create-nonce'),
'ajax_follow_success' => $this->follow_me_success(),
));
AJAX Call
var user_to_follow = $('.km-author-follow a.km-meta-badge').attr('id');
$.ajax( {
url : ajax_setting.ajax_url,
type : 'post',
data: {
action : 'theme_ajax_follow_me',
security : ajax_setting.ajax_nonce,
'data-follow-user' : user_to_follow,
},
success: function( data ) {
$('.km-follow-me').html( ajax_setting.ajax_follow_success ).hide().fadeIn( 'slow' );
console.log( user_to_follow );
},
} )
Inside the wp ajax function I use this
public function theme_addon_ajax_follow_me() {
...
$target_user = isset( $_POST['data-follow-user'] ) ? $_POST['data-follow-user'] : false;
if( ! empty( $_POST['data-follow-user'] ) ) {
$this->kiwi_follow_user( $current_user, $target_user );
}
wp_die();
}
Up next; this function sends the $target_user ID to km_follow_me_author_name
public function kiwi_follow_user( $current_user = 0, $user_to_follow = 0 ) {
...
$args = array(
'user_id' => $current_user,
'follow_to' => $user_to_follow
);
$response_success = $this->km_follow_me_author_name( $args );
}
Function to grab display name based on AJAX's $_POST['data-follow-user']
public function km_follow_me_author_name( $args = array() ) {
$author_info = get_userdata( $args['follow_to'] );
$author = $author_info->display_name;
return $author;
}
The success message and where it goes wrong. $name remains blank.
public function follow_me_success() {
$name = $this->km_follow_me_author_name();
$content = sprintf( esc_html__( 'You\'re now following %s.', 'theme' ), $name );
return $content;
}
Any help is much appreciated.

Answer 1

First I removed this line from wp_localize_script
'ajax_follow_success' => $this->follow_me_success(),
Then changed the success function from AJAX to:
$('.km-follow-me').html(data).hide().fadeIn( 'slow' );
Then inside public function kiwi_follow_user I used:
if ( ! empty( $response ) && $response !== FALSE ) {
$this->km_follow_me_success( $user_to_follow );
}
And inside the follow_me_success function, I replaced return with echo instead.
public function follow_me_success( $target_user = 0 ) {
$name = $this->km_follow_me_author_name( $target_user );
$content = sprintf( esc_html__( 'You\'re now following %s.', 'theme' ), $name );
echo $content;
}
Minor changes, big difference. :)