[Ethereum] Convert contract arguments from JSON to ABI-encoded format

abicontract-developmentverify

I want to verify a contract code on Etherscan, but don't know how to get the arguments in ABI-encoded format. I have the source code and the interface in JSON. Is there some tool I can use, or some easy way of getting the JSON to the ABI format?

Note: I used just the "Deploy Contract" from Ethereum Wallet (Mist), no fancy compiler or anything.

The source code: https://gist.github.com/crutor0x/45cd845349345190458df7f7412654e8

JSON ABI: https://gist.github.com/crutor0x/dd97e9593ffb696bfb583481dccb86d9

Contract address: 0x3c75226555fc496168d48b88df83b95f16771f37

Best Answer

The page "Verify Contract" ask for "Constructor Arguments ABI-encoded".

In your case the constructor has no parameters, so you can leave such field empty.

In the general case when your constrctor has parameters you can proceed as follow:

You can use ethereumjs-abi to encode/decode the parameters for transaction calls.

Let's suppose your constructor is MyToken(address _to, uint256 _value, bool _enabled). The parameters types are ["address", "uint256", "bool"].

If you have created the contract MyToken("0x1234567812345678", 0x314159268, true). Then the parameters values are ["0x1234567812345678", "0x314159268", true].

Then you can encode the values with rawEncode(parameterTypes, parameterValues).

var abi = require('ethereumjs-abi')

var parameterTypes = ["address", "uint256", "bool"];
var parameterValues = ["0x1234567812345678", "0x314159268", true];

var encoded = abi.rawEncode(parameterTypes, parameterValues);

console.log(encoded.toString('hex'));

On execution it will output

000000000000000000000000000000000000000000000000123456781234567800000000000000000000000000000000000000000000000000000003141592680000000000000000000000000000000000000000000000000000000000000001

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