In order to allow more complex filters, it could be interesting to be able to write raw solr filters within a template fetch.
This way, we would be able to add some sort of basic attribute filters or any kind of filters, at a template level and directly in solr syntax, a powerful way to face some special situations.

The raw filter system currently exists on a ini-basis, but won't be easily usable everywhere as it will happen on every request. As eZ Find gives a pre-requisite on solr, it should be helpful to have a full hand on it while writing search requests. This could at least help some experts to face some complex and original situations.

A basic implementation of a raw filter for eZfind search is attached, simply usable by including a "raw_filter" parameter, ie:
{$search=fetch( 'ezfind', 'search',
hash( query, '',
class_id,'17',
raw_filters, array( 'attr_birthdate_dt:[2002-03-10T00:00:00Z TO 2002-04-09T00:00:00Z]' )
) )}