Asynchronously performs a forward geocoding query using the this.
Use forward_search to do the same thing synchronously.
The params hash table is in the format used by Telepathy, and documented in the
Telepathy
specification.
See also: XEP-0080 specification.
When the operation is finished, callback will be called. You can then call
forward_search_async.end to get the result of the operation.
| this |
a Backend. |
| cancellable |
optional Cancellable, null to ignore. |
| callback |
a TaskReadyCallback to call when the request is satisfied |
| params |
a GenericSet with string keys, and Value values. |
| user_data |
the data to pass to the |