Doctrine - getChildren() with conditions?

Question

Hi,

I'm trying to write a basic plugin for the Symfony based CMS Diem. I'm trying to list of the child pages for the current page, which I have managed to do:

 $page = $this->getPage();
 $this->subpages = $page->getNode()->getChildren();

However, I'm unsure of the syntax to use in order to filter the child records with conditions. I would actually like to get just the records where the is_active field == 1.

I've looked at the documentation and I think I need to use the setBaseQuery method, but I could really do with an example to get me started.

Can anyone help?

Any advice appreciated. Thanks.