join_async
Description:
Join channel this with message as join message.
When we joined the channel, callback will be called. You can then call join_async.end to get the
result of the operation.
Note that unlike leave_async,
TP_CHANNEL_FEATURE_GROUP feature must be prepared before calling this function.
Parameters:
| this |
a Channel |
| message |
the join message |
| callback |
a callback to call when we joined the channel |
| user_data |
data to pass to |