Suppress deprecated notices

Question

When I use:

define('WP_DEBUG', 1);

In my wp-config.php, it works fine, but I am hacking an old theme and I would like to suppress deprecated notices.

My understanding is that adding this:

error_reporting( E_ERROR | E_NOTICE | E_PARSE )

Should do the trick. I have added it to wp-config.php and to header.php in my theme. Unfortunately, it has no effect. Is this something set at server level? Also the following makes no difference as well:

ini_set('display_errors', 1);

As asked in the comments below here's a couple of the notices. I am using a hacked version of the Construct 2 theme, quite old now but it would not be safe to update it. I am trying to persuade the client to let me rewrite it, the site is fairly simple, but as he can't see anything wrong, it's not broken, he won't spend the money.

Deprecated: Assigning the return value of new by reference is deprecated in /Volumes/Macintosh HD/Sites/MAMP (custodian)/wordpress/wp-content/themes/construct2/option-tree/ot-loader.php on line 369

Strict Standards: Declaration of DropDown_Nav_Menu::start_lvl() should be compatible with Walker_Nav_Menu::start_lvl(&$output, $depth = 0, $args = Array) in /Volumes/Macintosh HD/Sites/MAMP (custodian)/wordpress/wp-content/themes/construct2/dropdown-menus.php on line 192

Answer 1

I was able to suppress notices in the log and displayed errors by using the error_reporting function in a must-use plugin, which is loaded early enough to catch most of the WP core code warnings. This is helpful for the warnings coming from core/plugin files that you shouldn't modify.

I created a php file in the /wp-content/mu-plugins/ folder with this code:

<?php 
error_reporting(E_ALL & ~E_WARNING & ~E_DEPRECATED & ~E_USER_DEPRECATED & ~E_NOTICE);
?>

Answer 2

As mmm stated:

in which file appears the first notice?

Wherever the notice is mentioning the location of this deprecated function (path/to/some/file.php), you would insert the following just below the <?php tag which starts off the file:

error_reporting(0);

I've tried the above functions you mentioned and inserted them in my wp-config.php when I experience something similar, but they didn't work for me. This will turn off warning, deprecated, and everything else except the errors.

Answer 3

This is probably the most "WordPress" way to do it.

The code MUST go in your wp-config file, after the WP_DEBUG (and any other) defines because this particular filter runs before any plugins are loaded.

$GLOBALS['wp_filter'] = array(
'enable_wp_debug_mode_checks' => array(
    10 => array(
        array(
            'accepted_args' => 0,
            'function'      => function () {
                if ( defined( 'WP_DEBUG' ) && WP_DEBUG ) {
                    // *** This is the key line - change to adjust to whatever logging state you want
                    error_reporting( E_ALL & ~E_DEPRECATED );

                    ini_set( 'display_errors', defined( 'WP_DEBUG_DISPLAY' ) && WP_DEBUG_DISPLAY ? 1 : 0 );

                    if ( in_array( strtolower( (string) WP_DEBUG_LOG ), array( 'true', '1' ), true ) ) {
                        $log_path = WP_CONTENT_DIR . '/debug.log';
                    } elseif ( is_string( WP_DEBUG_LOG ) ) {
                        $log_path = WP_DEBUG_LOG;
                    } else {
                        $log_path = false;
                    }

                    if ( $log_path ) {
                        ini_set( 'log_errors', 1 );
                        ini_set( 'error_log', $log_path );
                    }

                    if (
                        defined( 'XMLRPC_REQUEST' ) || defined( 'REST_REQUEST' ) || defined( 'MS_FILES_REQUEST' ) ||
                        ( defined( 'WP_INSTALLING' ) && WP_INSTALLING ) ||
                        wp_doing_ajax() || wp_is_json_request() ) {
                        ini_set( 'display_errors', 0 );
                    }
                }

                return false;
            },
        ),
    ),
));

Answer 4

it seems many plugins change this value as well, so, i have had good luck with these two approaches,

// trying to be the last person to set this value
add_action('wp_loaded', function() { error_reporting( E_ALL & ~E_NOTICE ); 
});

// even later, but, not too late
add_action('wp', function() { error_reporting( E_ALL & ~E_NOTICE ); 
});

Answer 5

With the following you can just remove deprecated from whatever is the current error reporting setting. Adding it to your themes functions.php hides all deprecation errors.

error_reporting(error_reporting() & ~E_DEPRECATED);