source state, sourcestate, kPMElementSourceState — Source states.
source state: string, choice, default
source state is a string. If
source state is omitted, the default
waiting is used.
source state must be one of the following three constants:
kPMElementSourceState_Waiting. Source is waiting for next update.
kPMElementSourceState_Fetching. Source is checking for an update.
kPMElementSourceState_Error. Source encountered an error and is inactive.