ethereum/solidity

The Solidity Contract-Oriented Programming Language - By chatting here you agree to the https://github.com/ethereum/solidity/blob/develop/CODE_OF_CONDUCT.md

iFA

@iFA88

many thanks the tip, i will try that, but now i have downgraded to 0.4.26

I call delegatecall even in inline asm

Ayushya Chitransh

@AyushyaChitransh

Hi, I am using multiple string parameters in a function, but transaction is failing. Its a simple function which is running okay in JVM but failing in test network.

Lauri Peltonen

@microbecode

What's the error message?

How many strings?

8 is the maximum

Ayushya Chitransh

@AyushyaChitransh

am just using 4 string

I'll share the function

function registerCar(string memory _liscence, string memory _color, string memory _brand, string memory _model) public{
        totalCars++;
        car memory newCar = car({
            liscence: _liscence,
            serialNumber: totalCars,
            color: _color,
            brand: _brand,
            model: _model
        });
        carSerialNumber[totalCars] = newCar;
    }

Strange thing is that it is running fine inJVM but failing in testnet

Here is the entire contract:

pragma solidity ^0.5.0;

contract carRegister{
    struct car{
        string liscence;
        string color;
        string brand;
        string model;
        uint256 serialNumber;
    }

    uint256 public totalCars = 0;
    mapping(uint256 => car) public carSerialNumber;

    function registerCar(string memory _liscence, string memory _color, string memory _brand, string memory _model) public{
        totalCars++;
        car memory newCar = car({
            liscence: _liscence,
            serialNumber: totalCars,
            color: _color,
            brand: _brand,
            model: _model
        });
        carSerialNumber[totalCars] = newCar;
    }
}

Ayushya Chitransh

@AyushyaChitransh

Ahh, its probably a compiler issue. I changed the compiler to pragma solidity 0.5.0 and now its working fine

Muhammad Yasir

@SyedMuhamadYasir

i got a question

dApps are based on smart contracts, right ?

so, for an end user to use smart contract ( to issue calls to different functions basically ), do their machines have to be an Ethereum node ?

since you can't interact with smart contracts without being on the ethereum network...

also, how would dApps work on handheld devices ( like iOS and Android ) ? surely most mobile devices can't be capable of becoming ethereum nodes, right ?

Lauri Peltonen

@microbecode

well you just need access to some node

it doesn't have to be on your machine

I don't see a reason why you couldn't run a node on mobile if you have enough space

and connectivity

Muhammad Yasir

@SyedMuhamadYasir

if we're accessing some node, how can we safely say it's an honest node ?

and not an attacker or malicious node ?

i highly doubt a smartphone could run a full node

at most, a light client

feel free to add to the discussion, i'm open to all sorts of insights !

jochem-brouwer

@jochem-brouwer

you run a light client to validate the PoW chain and headers -> you can hence get things like merkle root of state. if you then request a merkle proof you can verify that at block x the state of something (e.g. account balance) is correct. in case a malicious node reports something else than actual balance then the proof will not result in the right state root

Evgeniy Shishkin

@unboxedtype

You can issue requests to several full nodes in random order, it does not have to be a single static node. Regarding running a full node on mobile device, well, you will have problems running full node even on a workstation PC if it lacks SSD drive and high speed inet connection.

jochem-brouwer

@jochem-brouwer

you dont need a full node to verify that the data is correct

Ayushya Chitransh

@AyushyaChitransh

Hello, has anyone faced issue n sending transactions to contract

Lauri Peltonen

@microbecode

every now and then

but the fault is always in me

Ayushya Chitransh

@AyushyaChitransh

I am unable to call write methods of a contract

can you provide me some helpful code

@microbecode

Lauri Peltonen

@microbecode

um, how are you trying to do it?

Shakeib Shaida

@shakeib98

@AyushyaChitransh how are you trying to do it? Using web3?

Ayushya Chitransh

@AyushyaChitransh

Yes using web3.

I'll share the code

 web3.eth.getTransactionCount(config.contract.accountAddress).then(function(nonceVal){
        let transactionObject = {
            from: config.contract.accountAddress,
            nonce: web3.utils.toHex(nonceVal),
            gas: gasLimit,
            gasPrice: gasPrice
        }

        return carRegister.methods.registerCar(carDetails.liscence, carDetails.color, carDetails.brand, carDetails.model )
            .send(transactionObject)
            .on('transactionHash', function(hash){
                console.log( "Hash", hash );
            })
            .on('confirmation', function(confirmationNumber, receipt){
                console.log( "confirmationNumber:", confirmationNumber );
            })
            .on('receipt', function(receipt){
                 console.log("receipt:", receipt);
            })
            .on('error', console.error)
            .catch(function(error){
                console.log( "failed somewhere", error);
                return {"registered": "false"};
            })

Ayushya Chitransh

@AyushyaChitransh

When I log the nonceVal, I am getting that data but the carRegister method return invalid JSON RPC response error

Ayushya Chitransh

@AyushyaChitransh

methods.myMethod.send how will this sign any transaction?

realisation

@realisation

should I assert or require when I try to execute an ERC20 send?

Lauri Peltonen

@microbecode

rule of thumb: assert should never fail and if it does it means a bug in code

chunfeng9128

@chunfeng9128_twitter

Hello everone,I created a communication group on the telegraph, I hope everyone can participate in the discussion together.https://t.me/joinchat/KmeyeBL6AaPIFOVmOPpUsw

Hadrien Croubois

@Amxx

Is there a way to call the new chainId opcode in solidity / inline assembly ? if no, is it planned ?

jochem-brouwer

@jochem-brouwer

@Amxx I checked the repository, it looks like chainid can be called in assembly.

contract ChainID {

    function getChainID() external view returns (uint) {
        uint id;
        assembly {
            id := chainid()
        }
        return id;
    }
}

Sol 0.5.12. You need to set compiler target evm to Istanbul

matrixbot

@matrixbot

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