calling a payable function with parameters

[ungaro]

i'm struggling to find an example to use a payable function with parameters.

let's say i've an function in my Smart Contract:

    function doSomething(address[] _adresses, address[] _groups, uint[] _percentages)
        public
        payable
        returns(address) {

How do i call this SC and send ethers to it & pass parameters and get the return value?

Thanks.

[shamatar]

Hello @ungaro

First of all you should understand that if the function is mutating (like one above) you are not guaranteed that a return value will in fact be the same when you check for it and when transaction executes.

1. how to get a return value:

• encode the parameters into the “TransactionIntermediate”. Please check the various examples in tests
• use the “call” method on this intermediate and supply required options (Web3Options struct) into the call. One of the field in options is “value” - it’s an amount of Wei (1 ETH = 10^18 wei) attached to the transaction
• upon execution you will get returned parameters

2. to send a transaction

• make an intermediate
• use the “send” method and supply the options

I recommend you to go through the tests of web3swift to check the examples.

Sincerely, Alex

[blockcowboy]

Can you give example how to trap error from a send call based on this? Not familiar with the way you have used Result.

guard let tokenNameRes = intermediate?.send(options: options) else {return}
        guard case .failure(let resultError) = tokenNameRes else {
            print(tokenNameRes)
            return}
        guard case .success(let result) = tokenNameRes else {
            print(tokenNameRes)
            return

[shamatar]

@blockcowboy

You almost have made it right

   let result = intermediate.send()
   switch result {
   case .success(let successResult):
   // this is successful result, use successResult for your activity
   case .failure(let error):
   // work with an error
   }

P.S. Sorry, don’t have markdown on a phone

[skywinder]

@blockcowboy did you solve your task?

[TonioMacaronio]

It seems that the issue is resolved, so its closed