Standard form type for editing mutlivalue? (Symfony CMF PHPCR)

Question

I'm using Sonata Admin as a backend. I have within PHPCR Document field that is multivalued (i.e. in PHP an array of strings). Now I'd like to add/remove elements from it within Sonata admin. Which type should I use? Tried collection, but I get nothing in admin; when I try sonata_type_collection admin expects from me admin code (I guess another admin), which is not the case.

Which form type should I use for a Document's field like the one below?

/**
 * @PHPCR\String(nullable=true, multivalue=true)
 */
protected $tags;

Answer 1

There is a chapter on form types for PHPCR-ODM in the cmf documentation. There is BurgovKeyValueBundle that allows you to edit associative arrays. For non-associative multivalue fields, i think you just need to use the array type of sonata admin.