Parsing solidity bytes to params

Question

I have two functions on contract:

function 1 receives bytes params variable

function foo1(bytes memory params)

function 2 receives two params: address param1, uint256 param2

function foo2(address param1, uint256 param2)

my goals somehow pass params as bytes to foo1, decode it on function, and pass decoded params to foo2

like:

function foo2(address param1, uint256 param2) {
   // do something
}

function decode(bytes params) private returns(???){
  // decode
}

function foo1(bytes params) public {
  var decodedParams = fromBytes(params)
  foo2(decodedParams.param1, decodedParams.param2)
}

from frontend I expect something like:

  const params = toBytes({param1: '0xAddRess', param2: 1})

  myContract.foo1(params)

Answer 1

You can use the Solidity built-in function abi.decode for this.

(address param1, uint256 param2) = abi.decode(params, (address, uint256));

For a real-world example, see how I use abi.decode in a flash swap contract that pulls liquidity from Uniswap V2: HifiFlashUniswapV2.