Hello World
Here is a hello-world example that sends and receives cross-chain messages with simple logics:
- Users call
sendMessageon the source chain to send a cross-chain message. - The receiver side implements
executeMessageto receive and emit the message at the destination chain.
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// A HelloWorld example for basic cross-chain message passing
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contract MsgExampleBasic is MessageApp {
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event MessageReceived(
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address srcContract,
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uint64 srcChainId,
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address sender,
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bytes message
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);
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constructor(address _messageBus) MessageApp(_messageBus) {}
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// called by user on source chain to send cross-chain messages
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function sendMessage(
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address _dstContract,
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uint64 _dstChainId,
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bytes calldata _message
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) external payable {
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bytes memory message = abi.encode(msg.sender, _message);
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sendMessage(_dstContract, _dstChainId, message, msg.value);
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}
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// called by MessageBus on destination chain to receive cross-chain messages
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function executeMessage(
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address _srcContract,
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uint64 _srcChainId,
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bytes calldata _message,
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address // executor
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) external payable override onlyMessageBus returns (ExecutionStatus) {
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(address sender, bytes memory message) = abi.decode(
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(_message),
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(address, bytes)
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);
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emit MessageReceived(_srcContract, _srcChainId, sender, message);
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return ExecutionStatus.Success;
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}
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}
Last modified 1yr ago