Вы можете использовать его в let contract = Web3.InfuraMainnetWeb3().contract(<abiString: String>, at: <EthereumAddress?>, abiVersion: <Int>)
Также вы должны вызвать необходимый метод: let transaction = contract.method(<method: String>, parameters: <[AnyObject]>, extraData: <Data>, options: <Web3Options?>)
Пример подготовки функции транзакции:
let yourContractJsonABI = "[{\"constant\":true,\"inputs\":[],\"name\":\"name\",\"outputs\":[{\"name\":\"\",\"type\":\"string\"}],\"payable\":false,\"type\":\"function\"},{\"constant\":false,\"inputs\":[{\"name\":\"_spender\",\"type\":\"address\"},{\"name\":\"_value\",\"type\":\"uint256\"}],\"name\":\"approve\",\"outputs\":[{\"name\":\"success\",\"type\":\"bool\"}],\"payable\":false,\"type\":\"function\"},{\"constant\":true,\"inputs\":[],\"name\":\"totalSupply\",\"outputs\":[{\"name\":\"\",\"type\":\"uint256\"}],\"payable\":false,\"type\":\"function\"},{\"constant\":false,\"inputs\":[{\"name\":\"_from\",\"type\":\"address\"},{\"name\":\"_to\",\"type\":\"address\"},{\"name\":\"_value\",\"type\":\"uint256\"}],\"name\":\"transferFrom\",\"outputs\":[{\"name\":\"success\",\"type\":\"bool\"}],\"payable\":false,\"type\":\"function\"},{\"constant\":true,\"inputs\":[],\"name\":\"decimals\",\"outputs\":[{\"name\":\"\",\"type\":\"uint8\"}],\"payable\":false,\"type\":\"function\"},{\"constant\":true,\"inputs\":[],\"name\":\"version\",\"outputs\":[{\"name\":\"\",\"type\":\"string\"}],\"payable\":false,\"type\":\"function\"},{\"constant\":true,\"inputs\":[{\"name\":\"_owner\",\"type\":\"address\"}],\"name\":\"balanceOf\",\"outputs\":[{\"name\":\"balance\",\"type\":\"uint256\"}],\"payable\":false,\"type\":\"function\"},{\"constant\":true,\"inputs\":[],\"name\":\"symbol\",\"outputs\":[{\"name\":\"\",\"type\":\"string\"}],\"payable\":false,\"type\":\"function\"},{\"constant\":false,\"inputs\":[{\"name\":\"_to\",\"type\":\"address\"},{\"name\":\"_value\",\"type\":\"uint256\"}],\"name\":\"transfer\",\"outputs\":[{\"name\":\"success\",\"type\":\"bool\"}],\"payable\":false,\"type\":\"function\"},{\"constant\":false,\"inputs\":[{\"name\":\"_spender\",\"type\":\"address\"},{\"name\":\"_value\",\"type\":\"uint256\"},{\"name\":\"_extraData\",\"type\":\"bytes\"}],\"name\":\"approveAndCall\",\"outputs\":[{\"name\":\"success\",\"type\":\"bool\"}],\"payable\":false,\"type\":\"function\"},{\"constant\":true,\"inputs\":[{\"name\":\"_owner\",\"type\":\"address\"},{\"name\":\"_spender\",\"type\":\"address\"}],\"name\":\"allowance\",\"outputs\":[{\"name\":\"remaining\",\"type\":\"uint256\"}],\"payable\":false,\"type\":\"function\"},{\"inputs\":[{\"name\":\"_initialAmount\",\"type\":\"uint256\"},{\"name\":\"_tokenName\",\"type\":\"string\"},{\"name\":\"_decimalUnits\",\"type\":\"uint8\"},{\"name\":\"_tokenSymbol\",\"type\":\"string\"}],\"type\":\"constructor\"},{\"payable\":false,\"type\":\"fallback\"},{\"anonymous\":false,\"inputs\":[{\"indexed\":true,\"name\":\"_from\",\"type\":\"address\"},{\"indexed\":true,\"name\":\"_to\",\"type\":\"address\"},{\"indexed\":false,\"name\":\"_value\",\"type\":\"uint256\"}],\"name\":\"Transfer\",\"type\":\"event\"},{\"anonymous\":false,\"inputs\":[{\"indexed\":true,\"name\":\"_owner\",\"type\":\"address\"},{\"indexed\":true,\"name\":\"_spender\",\"type\":\"address\"},{\"indexed\":false,\"name\":\"_value\",\"type\":\"uint256\"}],\"name\":\"Approval\",\"type\":\"event\"},]"
func prepareTransaction(parameters: Data, gasLimit: BigUInt = 27500, completion: @escaping (Result<TransactionIntermediate>) -> Void) {
DispatchQueue.global().async {
guard let addressFrom: String = <YOURS WALLET ADDRESS> else {return}
guard let ethAddressFrom = EthereumAddress(addressFrom) else {return}
let yourContractAddress = "<YOUR CONTRACT ETH ADDRESS>"
guard let ethContractAddress = EthereumAddress(contractAddress) else {return}
let web3 = Web3.InfuraMainnetWeb3() //or any test network
web3.addKeystoreManager(KeystoreManager.defaultManager)
var options = Web3Options.defaultOptions()
options.from = ethAddressFrom
options.value = 0 // or any other value you want to send
guard let contract = web3.contract(yourContractJsonABI, at: ethContractAddress, abiVersion: 2) else {return}
guard let gasPrice = web3.eth.getGasPrice().value else {return}
options.gasPrice = gasPrice
options.gasLimit = gasLimit
guard let transaction = contract.method("<METHOD OF CONTRACT YOU WANT TO CALL>", parameters: [parameters] as [AnyObject], options: options) else {return}
guard case .success(let estimate) = transaction.estimateGas(options: options) else {return} //here is estimated gas - something like confirming that you made a transaction correctly
print("estimated cost: \(estimate)")
DispatchQueue.main.async {
completion(Result.Success(transaction))
}
}
}