Hi all,

I am using GridField to manage a many_many relationship between a page type and a data object. My question is, if you delete the relation (Not the object itself), how do you get it back later if you don't remember the object name. For example, now I have a page which contains product A, when I click "unlink" in the GridField, you don't see product A anymore, but actually it still exists, I know you can search "product A" to find it and link it again, but what if you don't remember it? Is there a way to independently manage Product objects?

Thanks.

Have a look at ModelAdmin.

Thanks a lot, Simon. BTW, is there a way to automatically delete relations when you delete an object? I tried to remove relations manually but it looks like the mapping table class isn't auto-loaded, e.g. Category_Product::get() will give you an error saying "cannot find this class".

checkout onBeforeDelete

I use

foreach( $this->relations() as $relation ) {
$relation->delete();
}

http://doc.silverstripe.com/framework/en/topics/datamodel#onbeforedelete

That'll delete the related objects, but it won't clean the relation table. Usually, that doesn't matter since the table has to be rather large before you'd notice any sort of performance penalty.

What you're after is the removeAll() method on RelationList. Something like:

	public function onBeforeDelete() {
		parent::onBeforeDelete();
		$this->RelationName()->removeAll();
	}

Interesting I never knew :)
Will update my code to removeAll();

Thanks Simon_w