Forwarder Construction

[primozkocevar]

When Forwarder is constructed by the WalletSimple contract by calling createForwarder() it does not return an address of a newly created Forwarder contract. This error occurs when running on the main chain but everything works when using a local test chain.

[acinmavi]

Same here , I used Ropsten Testnet.
If deploy Forwarder only , it works fine , return contract address and forward any coin deposit to this contract address.
But if deploy WalletSimple and call createForwarder() , it return an transaction info without contract address.
I wonder why WalletSimple has include this function , what purpose of this ?

[primozkocevar]

I actually have a solution for this in my version of the contracts with 2 added global variables.
I describe this here: https://medium.com/valus/forwarder-contract-for-ether-and-erc-20-tokens-e257a621889d
However, the implemented contract here is also a bit different as it is a bit simpler but you can only add the public variables and it should work.
P.S.: If it helps I can also make a merge request with my fork.

[cauta]

if you use createForwarder by WalletSimple. the new forwarder will be displayed in internal transaction

[nguyennk92]

The Forwarder address can actually be calculated in advance, it is basically keccak256 of the contract address and its nonce in hex.
The implementation in JS is as follow:

    import * as utils from "ethereumjs-util";

    const nonceContract = await web3.eth.getTransactionCount(contractAddress)
    nonceHex = web3.utils.toHex(nonceContract)
    const rlpEncoded = utils.rlp.encode([contractAddress, nonceHex])
    const forwarderAddr = "0x" + utils.keccak256(rlpEncoded).slice(12).toString('hex')