Extend custom page model with another model

The CMS Questions
1

I am trying to extend a custom page model with another model, but cannot get it to work.
Maybe someone has an idea?

This is my base model under site/models/date.php:

<?php

use Kirby\Cms\Page;

class DatePage extends Page
{
…
}

I am trying to extend it here site/models/date.external.php:

<?php

require 'date.php';

class DateExternalPage extends DatePage
{
…
}

This is the error I get:
Cannot declare class DatePage, because the name is already in use

2

Ok, I solved this pretty much immediately after opening the thread.
I actually had multiple models that extend the default model, and I required the default in each of them, which of course threw an error. I fixed it by only requiring it in the one that comes first alphabetically.

3

You don’t have to require those files.

4

If I don’t, I get this error:

Class "DatePage" not found

5

Oh, you are right, depends on load order.