def invite_members():
"""
Invite member as an initialization step after a `PostmanRole` contract is seen.
"""
return init(). \
from_(PostmanRole). \
update([PostmanRole.InviteParticipant(
party=member['party_name'],
address=member['party_address'])
for member in MEMBERS])
def send_to_five_friends(member):
"""
Send letters to five friends for the given member.
"""
# This is just a demonstration; in a real system, this interaction would
# likely have to happen "outside" the ledger program.
party_index = member['party_index']
party_address = member['party_address']
return init(). \
from_(AuthorRole). \
update([AuthorRole.CreateLetter(
address=party_address,
content='I am a letter from {} to {}.'.format(party_index, friend_index))
for friend_index in
[i % len(MEMBERS) for i in range(party_index + 1, party_index + 6)]])
def set_up() -> Application:
"""
Create the application.
"""
app_builder = ApplicationBuilder()
app_builder.as_party('POSTMAN'). \
add(init().update(PostmanRole(postman='POSTMAN'))). \
add(invite_members()). \
add(sort_and_deliver())
for member in MEMBERS:
party = member['party_name']
app_builder.as_party(party). \
add(InviteAuthorRole.Accept()). \
add(InviteReceiverRole.Accept()). \
add(send_to_five_friends(member))
return app_builder.build()