simple condition on wordpress function.php not work - php

Question

i want add a new field "title" on comment of wordpress, after insert the new input field in a default form of wordpress i added this in my function.php for save the title when new comment are submitted.
this is the code i use for save title:
function add_comment_meta_values($idcommento) {
global $post;
$idcommento= get_comment_ID();
$tipodipost= get_post_type($post->ID);
if( get_post_type($post->ID) == 'service') {
if(isset($_POST['title_svz']) ) {
$title= wp_filter_nohtml_kses($_POST['title_svz']);
add_comment_meta( $idcommento , 'title_svz', $title, false);
}}
}
add_action ('comment_post', 'add_comment_meta_values', 1);
this code work only when remove the condition :
if( get_post_type($post->ID) == 'service') {}
and i don't understand why, i have already tried this condition in comment.php or in a footer with simple function like this
function test_function() {
if( get_post_type($post->ID) == 'service') { echo 'done'; }
}
add_action( 'wp_footer', 'test_function' );
and it's work, so i don't understand why don't work in my primary code, any idea ?
SOLVED MYSELF
THIS IS THE NEW CODE:
function add_comment_meta_values($idcomment) {
$comment_full = get_comment( $idcomment );
$idpost = $comment_full->comment_post_ID;
$typepost= get_post_type($idpost);
if( $typepost == 'service') {
if(isset($_POST['title_svz']) ) {
$title= wp_filter_nohtml_kses($_POST['title_svz']);
add_comment_meta( $idcomment , 'title_svz', $title, false);
} }
}
add_action ('comment_post', 'add_comment_meta_values', 10, 1);

Answer 1

Sometimes in Wordpress, depending on the Context, the global $post may give you unexpected result. Thus something like $post->ID may not point to the appropriate ID you are looking for. You may as well try inspecting the $post object to see if it is what you had expected; like so:
<?php
function add_comment_meta_values($idcommento) {
global $post;
// TRY DUMPING THE $post VARIABLE TO SEE WHAT YOU GET
var_dump($post->ID);
var_dump($post->post_type);
var_dump($post);
exit;
$idcommento = get_comment_ID();
$tipodipost = get_post_type($post->ID);
// ALTHOUGH THIS IS ESSENTIALLY THE SAME AS WHAT YOU DID
if( $post->post_type == 'service') {
if(isset($_POST['title_svz']) ) {
$title= wp_filter_nohtml_kses($_POST['title_svz']);
add_comment_meta( $idcommento , 'title_svz', $title, false);
}}
}
add_action ('comment_post', 'add_comment_meta_values', 1);
After the Inspection, you'd sure know where and what was not OK in your Code...