Data processing not only supports encoding (encode
), but also decoding (decode
). Use the exchange.IO("decode", types, rawData)
function to perform the decode
operation.
function main() {
// register SwapRouter02 abi
var walletAddress = "0x398a93ca23CBdd2642a07445bCD2b8435e0a373f"
var routerAddress = "0x68b3465833fb72A70ecDF485E0e4C7bD8665Fc45"
var abi = `[{"inputs":[{"components":[{"internalType":"bytes","name":"path","type":"bytes"},{"internalType":"address","name":"recipient","type":"address"},{"internalType":"uint256","name":"amountOut","type":"uint256"},{"internalType":"uint256","name":"amountInMaximum","type":"uint256"}],"internalType":"struct IV3SwapRouter.ExactOutputParams","name":"params","type":"tuple"}],"name":"exactOutput","outputs":[{"internalType":"uint256","name":"amountIn","type":"uint256"}],"stateMutability":"payable","type":"function"}]`
exchange.IO("abi", routerAddress, abi) // abi only uses the contents of the local exactOutput method, the full abi can be searched on the Internet
// encode path
var fee = exchange.IO("encodePacked", "uint24", 3000)
var tokenInAddress = "0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2"
var tokenOutAddress = "0xdac17f958d2ee523a2206206994597c13d831ec7"
var path = tokenInAddress.slice(2).toLowerCase()
path += fee + tokenOutAddress.slice(2).toLowerCase()
Log("path:", path)
var dataTuple = {
"path" : path,
"recipient" : walletAddress,
"amountOut" : 1000,
"amountInMaximum" : 1,
}
// encode SwapRouter02 exactOutput
var rawData = exchange.IO("encode", routerAddress, "exactOutput", dataTuple)
Log("method hash:", rawData.slice(0, 8)) // 09b81346
Log("params hash:", rawData.slice(8))
// decode exactOutput params
var decodeRaw = exchange.IO("decode", "tuple(path bytes,recipient address,amountOut uint256,amountInMaximum uint256)", rawData.slice(8))
Log("decodeRaw:", decodeRaw)
}
The example performs the encodePacked
operation first during the path
parameter processing, because the exactOutput
method call that needs to be encoded later needs the path
as the parameter.
Then, the encode
method of the exactOutput
routing contract has only one parameter, and the parameter type is tuple
.
The method exactOutput
name is encoded as 0x09b81346
, which is decoded the result decodeRaw
by exchange.IO ("decode",...)
method, and it is consistent with the variable dataTuple
.