Quickstart (Cross-chain text example)
This part goes over a simple example as well as how to send and receive message using anyCall.
Please fork the repo above and follow the readme.
This repo would deploy a solidity contract on two chains and send a text message from chain A to chain B. This is purposed to showcase anyCall V7 cross-chain messaging capability.
- 1.Fork the provided repository and install the dependencies using either yarn or npm(
yarn || npm install). - 2.Add your private key and Etherscan API keys (if you want to verify the contract on Etherscan) to the .env.example file. Rename the file to .env.
- 3.Deploy the example contract on the ftm and bnb testnets by running the following commands:
yarn hardhat deploy --network ftmtestyarn hardhat deploy --network bnbtest
- 4.To test the flow, run the following command and change the customMessage in 1testanycall.js to send a different message:
yarn hardhat run ./scripts/1testanycall.js --network ftmtest
Code Breakdown
The function below is an example. This sends a simple text message to the destination chain by using the anyCall funciton.
function step1_initiateAnyCallSimple_srcfee(string calldata _msg) payable external {
emit NewMsg(_msg);
if (msg.sender == owneraddress){
CallProxy(anycallcontract).anyCall{value: msg.value}(
receivercontract, //Destination Contract Address
abi.encode(_msg), //encoded string as bytes
destchain, //destination chain id
0, // Using 0 flag to pay fee on the source chain
"" //extra data used for advanced use cases
);
}
}
Here's a more detailed breakdown of the parameters.
function anyCall( address _to, bytes calldata _data, uint256 _toChainID, uint256 _flags, bytes calldata )The destination chain would call
anyExecute function on the _to address with _data passed in the function. And you can customize what you do with such _data.Param | Type | Description |
|---|---|---|
_to | address | The target contract to interact with on _toChainID |
_data | bytes | The calldata supplied for the interaction with _toanyExecute will be run with this _data on the receiver contract you deployed. |
_toChainID | uint256 | The target chain id to interact with |
_flags | uint256 | How dapps are paying gas fee of tx execution:
2: Gas fee paid on destination chain. 4: Allow fallback |
The following function named anyExecute would process the data sent. In this case, it'd simply decode the data and emit an event. The function must be called anyExecute.
function anyExecute(bytes memory _data) external returns (bool success, bytes memory result){
(string memory _msg) = abi.decode(_data, (string));
emit NewMsg(_msg);
success=true;
result='';
}
function anyExecute(bytes calldata data) external override onlyExecutor returns (bool success, bytes memory result)Param | Type | Description |
|---|---|---|
data | bytes | The calldata supplied for the interaction with subsequent contracts |
Returned Values | | |
success | bool | The address to call on _fromChainID if the cross chain interaction fails |
result | bytes | The originating chain id |
Last modified 5mo ago