How to debug save_post actions in WordPress? - php

Question

I have some custom post meta being generated and am ready to add to a post's meta. I know how to do this. However, save_post causes a redirection after POST data has been sent. This means I am redirected to the dashboard and lose access to my POST data - therefore I cannot debug easily.
Currently I am using something like:
add_action('save_post', 'something_process');
function something_process() {
if(defined('DOING_AUTOSAVE') && DOING_AUTOSAVE)
return;
print_r($_POST);
}
Is there a way to easily debug this?

Answer 1

The best approach for me has been to use a function to log the values to wp-content/debug.log, lifted from http://fuelyourcoding.com/simple-debugging-with-wordpress:
if(!function_exists('log_it')){
function log_it( $message ) {
if( WP_DEBUG === true ){
if( is_array( $message ) || is_object( $message ) ){
error_log( print_r( $message, true ) );
} else {
error_log( $message );
}
}
}
}
Then use the function like this in your save_post hook:
log_it($_POST);
log_it('The value for ' . $custom_field . ' is ' . $_POST[$custom_field]);
Make sure that wp-content/debug.log is writable, and that you have debugging enabled in wp-config.php:
#ini_set('display_errors',0);
define( 'WP_DEBUG', true ); // Turn debugging ON
define( 'WP_DEBUG_DISPLAY', false ); // Turn forced display OFF
define( 'WP_DEBUG_LOG', true ); // Turn logging to wp-content/debug.log ON
define( 'WP_POST_REVISIONS', false); // Disables revision functionality

Answer 2

Method 1:
if (isset($_POST)) die(print_r($_POST)); //answer by Tumas
Method 2:
create log file (my_logs.txt) in a folder, where you use this code:
add_action('save_post', 'something_process',11,11);
function something_process()
{
print_r($_POST);
$tmp = fopen(dirname(__file__).'/my_logs.txt', "a+"); fwrite($tmp,"\r\n\r\n".ob_get_contents());fclose($tmp);
}

Answer 3

The best solution I've found so far is storing the $_POST in a session var for access later.

Answer 4

First Approach:
die(print_r($post_id));
Second Approach:
var_dump($post_id);
Third Approach:
<?php
echo <pre>{whatever you want to echo goes here}</pre>
?>
Or take any browser add-ons for console logging
may one of three help..Good Luck

Answer 5

You could also save your debug messages in a WordPress option and show it as an admin message after the redirect.
// display all notices after saving post
add_action( 'admin_notices', 'show_admin_notices', 0 );
// your custom save_post aciton
add_action( 'save_post', 'custom_save_post' );
function custom_save_post() {
store_error_in_notices_option( 'my debug message' );
}
function store_error_in_notices_option( $m ) {
if ( ! empty( $m ) ) {
// store error notice in option array
$notices = get_option( 'my_error_notices' );
$notices[] = $m;
update_option( 'my_error_notices', $notices );
}
}
function show_admin_notices() {
$notices = get_option( 'my_error_notices' );
if ( empty( $notices ) ) {
return;
}
// print all messages
foreach ( $notices as $key => $m ) {
echo '<div class="error"><p>' . $m . '</p></div>';
}
delete_option( 'my_error_notices' );
}

Answer 6

I use this for a quick formatted output :
die( '<pre>' . print_r( $_POST, true ) . '</pre>');