entry_request_extra_metadata

@accepts(RB.RhythmDBEntry, utf8)
@returns(GObject.Value)
def entry_request_extra_metadata(entry, property_name)

Emits a request for extra metadata for the @entry. The @property_name argument is emitted as the ::detail part of the "entry_extra_metadata_request" signal. It should be a namespaced RDF predicate e.g. from Dublin Core, MusicBrainz, or internal to Rhythmbox (namespace "rb:"). Suitable predicates would be those that are expensive to acquire or only apply to a limited range of entries. Handlers capable of providing a particular predicate may ensure they only see appropriate requests by supplying an appropriate ::detail part when connecting to the signal. Upon a handler returning a non-None value, emission will be stopped and the value returned to the caller; if no handlers return a non-None value, the caller will receive None. Priority is determined by signal connection order, with %G_CONNECT_AFTER providing a second, lower rank of priority. A handler returning a value should do so in a GValue allocated on the heap; the accumulator will take ownership. The caller should unset and free the GValue if non-None when finished with it.