getting dashboard to filter on multiple types

Hi All,

n00b alert :D

i'm helping the webmaster of a local ELGG site by doing some of the coding for him and i think i'm getting the hang of it, but now i seem to be stuck

right now the site is using

elgg_view_river_items

which is called with either "all", or "object,blog" or "object,poll" or whatever

now, we would the user to select either "all" or any combination of the allowed content types

elgg_view_river_items

is using

get_river_items

to accomplish the original functionality and i foolishly thought that i could use

elgg_list_registered_entities

to do what i wanted, but there isn't very much documentation on the subject

any hints would be appreciated

Best regards,

McCoder