def subscribe(id, userId):
"""
Subscribe a user to a stream.
Parameters:
id - a stream id.
userId - a user id.
"""
db = core.connect()
theUser = db[userId]
theStream = db[id]
allowed = not theStream["private"]
if not allowed:
perms = permission.joinableStreams(userId)
allowed = id in perms
if allowed and (not id in theUser["streams"]):
theUser["streams"].append(id)
db[userId] = theUser
if theStream["private"]:
perm = permission.permissionForUser(userId, id)
permission.update(perm["_id"], 1)
def canSubscribe(id, userId):
"""
Return true if:
1. User is admin.
2. User created the stream.
3. The stream is public.
4. User has join permissions.
Parameters:
id - a stream id.
userId - a user id.
Returns:
bool.
"""
if user.isAdmin(userId):
return True
theStream = read(id)
if theStream["createdBy"] == userId:
return True
if not theStream["private"]:
return True
joinable = permission.joinableStreams(userId)
return id in joinable
