Is there an equivalent using DFC for api getfile or getcontent calls?  Use case is:  get the content of a rendition based on page_modifier (attribute of dmr_content).  The dql:  
select
dm_document.r_object_id, dmr_content.page_modifier
  from dmr_content,
dm_document (all)
where any
dmr_content.page_modifier > ' ' 
  and
dmr_content.full_format='pdf'
  and any
dmr_content.parent_id = dm_document.r_object_id