observer notifier question/opinions...

i am curious about opinions. in the past, i have stuck to the docs, with regards to updating values using an observer, ie $parm1 is read only and 2-9 are update-able. see:

https://docs.zen-cart.com/dev/code/notifiers/#update

so if one were to look at this observer:

$zco_notifier->notify('NOTIFY_SEARCH_ORDERBY_STRING', $listing_sql);

the $listing_sql is NOT update-able as it is in $p1 position. however, if we were to add the $listing_sql to the global line in the update function, we can now change it, ie:

      public function update(&$class, $eventID, &$p1, &$p2, &$p3, &$p4)
        {
            global $listing_sql;
            switch ($eventID) {
                case 'NOTIFY_SEARCH_ORDERBY_STRING':
                    $listing_sql = 'whatever the bloody heck i like';
                    break;
            }
        }

i am curious what the downside may be on this approach as well as whether it is worthy of including in the docs.

best.

The downside is the usual downside of using global variables; you create code that is much harder to debug and less self-documenting.

If you feel that it's important to be able to change the first parameter, the better approach (which has been used in the past) is to simply update

$zco_notifier->notify('NOTIFY_SEARCH_ORDERBY_STRING', $listing_sql);

to

$zco_notifier->notify('NOTIFY_SEARCH_ORDERBY_STRING', $listing_sql, $listing_sql);

This is upwardly compatible and the intent is clear.

swguy:

The downside is the usual downside of using global variables; you create code that is much harder to debug and less self-documenting.

If you feel that it's important to be able to change the first parameter, the better approach (which has been used in the past) is to simply update

$zco_notifier->notify('NOTIFY_SEARCH_ORDERBY_STRING', $listing_sql);

to

$zco_notifier->notify('NOTIFY_SEARCH_ORDERBY_STRING', $listing_sql, $listing_sql);

This is upwardly compatible and the intent is clear.

i am not a fan of this idea. the whole point is to not modify core code. changing the core code, i might as well as change the listing sql on that section of the code.

I'm suggesting you do this as a PR for inclusion into a future release. Like I said, this has been done in the past by people who needed exactly what you need.

Here's an example:

Zen Cart 1.5.6:
$zco_notifier->notify('NOTIFY_EMAIL_BEFORE_PROCESS_ATTACHMENTS', array('attachments'=>$attachments_list, 'module'=>$module));

Zen Cart 1.5.7:
$zco_notifier->notify('NOTIFY_EMAIL_BEFORE_PROCESS_ATTACHMENTS', array('attachments'=>$attachments_list, 'module'=>$module), $mail, $attachments_list);

Someone needed to be able to modify $attachments_list.

i misunderstood you.

when and if PRs start getting merged again, perhaps i will create one.

thanks.