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Smart Contract Events

Event Option​

Events in aelf smart contracts are used to represent occurrences during execution. These events are logged in the transaction traces.

Example of an event definition:

message Transferred {
    option (aelf.is_event) = true;
    aelf.Address from = 1 [(aelf.is_indexed) = true];
    aelf.Address to = 2 [(aelf.is_indexed) = true];
    string symbol = 3 [(aelf.is_indexed) = true];
    sint64 amount = 4;
    string memo = 5;
}
  • option (aelf.is_event) = true; indicates that Transferred is an event.

To trigger this event in a contract:

Context.Fire(new Transferred()
{
    From = from,
    To = to,
    ...
});

External code can monitor this event after the transaction execution.