Quotes missing when saving json data inside a database (ajax related) - php

Question

I noticed that I'm missing the usual quotes when using JSON data inside a database table. This only happens inside the second column Followers IDs
My code is as follows:
public function ajax_follow_me() {
check_ajax_referer( 'km-ajax-create-nonce', 'security' );
$current_user = get_current_user_id();
$target_user = isset( $_POST['data-follow-user'] ) ? $_POST['data-follow-user'] : false;
if( ! empty( $_POST['data-follow-user'] ) ) {
$this->follow_user( $current_user, $target_user );
}
wp_die();
}
Next step...
public function follow_user( $current_user = 0, $user_to_follow = 0 ) {
if ( empty( $user_to_follow ) ) {
return;
}
$args = array(
'user_id' => $current_user,
'follow_to' => $user_to_follow
);
$response = $this->add_following( $args );
if ( ! empty( $response ) && $response !== FALSE ) {
$args = array(
'user_id' => $user_to_follow,
'followed_by' => $current_user
);
$this->add_followed_by( $args );
$this->km_follow_me_success( $user_to_follow );
} else {
$this->km_follow_me_error();
}
}
First column:
public function add_following ( $args = array() ) {
global $wpdb;
$author_info = get_userdata( $args["user_id"] );
if ( empty( $author_info->display_name ) ) {
$author_name = $author_info->user_login;
} else {
$author_name = $author_info->display_name;
}
$defaults = array(
'user_id' => '',
'follow_to' => '',
'username' => $author_name,
'user_email' => $author_info->user_email
);
$args = wp_parse_args( $args, $defaults );
// First you have to check if the user already exists and return his Following Row
$following = array();
$existing = $wpdb->get_var( $wpdb->prepare( "SELECT following FROM {$this->table} WHERE user_id = %d", $args["user_id"] ) );
if( ! empty( $existing ) ) {
$following = json_decode( $existing, true );
}
// We check if this user ($args["user_id"]) is already following the $args["follow_to"] user.
if( in_array( $args["follow_to"], $following ) ) {
return TRUE;
} else{
array_push( $following, $args['follow_to'] );
}
// We verify if the user exists and update the value, if he does not and we sent username, then, we create it.
if( null === $existing && ! empty( $args['username'] ) ) {
$wpdb->insert( $this->table,
array(
'user_id' => $args['user_id'],
'username' => $args['username'],
'email' => $args['user_email'],
'following' => json_encode( $following ),
'followers' => json_encode( array() )
),
array( '%d', '%s', '%s', '%s', '%s' )
);
return $wpdb->insert_id;
} else {
$updated = $wpdb->update( $this->table,
array(
'following' => json_encode( $following )
),
array(
'user_id' => $args["user_id"]
),
'%s', '%d'
);
return $updated;
}
}
This code is for updating the second column (and where it's suppose to go wrong somewhere).
public function add_followed_by( $args = array() ) {
global $wpdb;
$author_info = get_userdata( $args['user_id'] );
if ( empty( $author_info->display_name ) ) {
$author_name = $author_info->user_login;
} else {
$author_name = $author_info->display_name;
}
$defaults = array(
'user_id' => '',
'followed_by' => '',
'username' => $author_name,
'user_email' => $author_info->user_email
);
$args = wp_parse_args( $args, $defaults );
// First you have to check if the user already exists and return his Followers Row
$followers = array();
$existing = $wpdb->get_var( $wpdb->prepare( "SELECT followers FROM {$this->table} WHERE user_id = %d", $args["user_id"] ) );
if( ! empty( $existing ) ) {
$followers = json_decode( $existing, true );
}
// We check if this user ($args["user_id"]) is already followed by $args["followed_by"] user.
if( in_array( $args['followed_by'], $followers ) ) {
return TRUE;
} else {
array_push( $followers, $args['followed_by'] );
}
// We verify if the user exists and update the value, if he does not and we sent username, then, we create it.
if( null === $existing && ! empty( $args['username'] ) ) {
$wpdb->insert( $this->table,
array(
'user_id' => $args['user_id'],
'username' => $args['username'],
'email' => $args['user_email'],
'following' => json_encode( array() ),
'followers' => json_encode( $followers )
),
array( '%d', '%s', '%s', '%s', '%s' )
);
return $wpdb->insert_id;
} else {
$updated = $wpdb->update( $this->table,
array(
'followers' => json_encode( $followers )
),
array(
'user_id' => $args["user_id"]
),
"%s", "%d"
);
return $updated;
}
}
Any help in the right direction is greatly appreciated.