I've got a GridField on a NewsHolder page listing NewArticlePages. Everything works great, and I can click the Create News Article Page button to create a new article. However, when I click Create, it saves the article, but doesn't publish it.

How can make it also Publish the article when it's first created?

Hey I'm not an expert so open to correction but I would try using an onAfterWrite() eg on NewsArticlePage

public function onAfterWrite() {
 $this->publish();
 parent::onAfterWrite();
}

as in http://doc.silverstripe.org/framework/en/topics/datamodel#onbeforewrite (but with after)

Thanks BlueO, I did try that, but as publish() calls write() which calls onAfterWrite() (and onBeforeWrite()), it just got stuck in an endless loop!

hmmm OK, maybe an 'if' to check if its published so:

public function onAfterWrite() { 
  if($this->Status != 'Published'){
    $this->publish(); 
  }
parent::onAfterWrite(); 
}

sorry haven't tested but that should stop it doing another write if the page has already been published