# Customizing

## Leaving fields out

A field left out of the merge saves as it does in plain Filament: the form's value is written, no matter who changed it in the meantime. Use this for a field whose value on this form should always win, such as one your page computes from other fields on save. A field a job or a webhook owns (a counter, a status) is safest kept in the merge, where the newer value stays unless you changed it, or taken off the form altogether:

```php
protected function getCoEditIgnoredFields(): array
{
    return ['slug']; // set from the title on every save
}
```

## Events

Listen for these to keep an audit trail or notify the person whose change was kept:

| Event | When | Payload |
| --- | --- | --- |
| `Packstub\CoEdit\Events\ChangesMerged` | A save that kept fields only the other person changed is committed | `record`, `user`, `fields`, `theirName` |
| `Packstub\CoEdit\Events\ConflictDetected` | A save found fields both changed | `record`, `user`, `fields`, `theirName` |
| `Packstub\CoEdit\Events\ConflictResolved` | The save carrying the person's choices from the dialog is committed | `record`, `user`, `choices` (field => `mine` or `theirs`) |

## Your own save()

If your edit page overrides `save()`, the trait's version is not used. Call the merge yourself and stop when it returns `false`, which means the conflict dialog is open. Wrap both in `whileSaving()` so two saves of the record never run at the same time. Call `coeditAfterSave()` once your save is done so the next merge starts from it. Without that call, your own save comes back as a conflict:

```php
use Packstub\CoEdit\CoEdit;

public function save(bool $shouldRedirect = true, bool $shouldSendSavedNotification = true): void
{
    CoEdit::store()->whileSaving($this->getCoEditRoom(), function (): void {
        if (! $this->coeditMergeBeforeSave()) {
            return;
        }

        // your save

        // Unless your save went through Filament's (parent::save()), which reports it:
        $this->coeditAfterSave();
    });
}
```

## Rooms

A room is one record: its database, its morph class and its key. The database is part of it so two tenants' product #5 stay apart in database-per-tenant apps. Tenants share a database name when each has its own Postgres schema, or when databases of the same name sit on separate servers; those apps need the resolver below, or their people see each other on records with the same key. To key rooms another way, for example per team on a shared database, register a resolver in a service provider:

```php
use Packstub\CoEdit\Presence\PresenceStore;

PresenceStore::resolveRoomUsing(fn (Model $record): string => $record->team_id.':'.$record->getMorphClass().':'.$record->getKey());
```

Presence on another Filament page that has a record and a header, such as a custom resource page, works the same way: use `HasPresence` and override `getCoEditRoom()`. Keep it `protected`, since a public method on a Livewire page can be called from the browser.