I have the following bit of code (note, I put the mail() function in only to see what the values are):

function system_init_actions() {

function system_save_number($oldvalue,$newvalue) {
    global $wpdb;
    global $table_prefix;
    mail('my@email.com','here',print_r($oldvalue,true) . "\n\n" . print_r($newvalue,true));
    $wpdb->update($table_prefix . "system_config",['status'=>'deactivated'],['number'=>$oldvalue]);
    $wpdb->insert($table_prefix . "system_config",['number'=> $newvalue,'created'=>date('Y-m-d H:i:s'),'status'=>'pending']);

In my plugin options page, I have an option named system_number. When I save that system number, I get an email (again, only to see the values) which means it is calling the function.

$newvalue is passed with no problem, but the function is not receiving $oldvalue. I had a look at the update_option() method in wp-includes/option.php and it fires do_action ( "update_option_{$option}", mixed $old_value, mixed $value ), which should pass the old value.

Why is it not giving me that value?


You should use pre_update_option_{option_name} filter.


function system_save_number( $new_value, $old_value ) {
    mail('my@email.com','here',print_r($old_value ,true) . "\n\n" . print_r($new_value,true));
    return $new_value;

function system_init_actions() {
    add_filter( 'pre_update_option_system_number', 'system_save_number', 10, 2 );

add_action( 'init', 'system_init_actions' );
| improve this answer | |
  • Out of curiosity, what is update_option_{$option}'s purpose then? – Albert Jun 24 '15 at 18:54
  • For this codex documentation is not available link – WisdmLabs Jun 24 '15 at 19:17

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