How to pass a string to a setter function in solidity?

Question

I am trying to execute a simple function in solidity where I pass a value to a set() function and it stores it in a predeclared variable in the Smart Contract.

The initial code presented by truffle unbox react works fine. You pass it an int and it returns the transaction hash.However, if I pass it a string, it throws me an error.

This is the initial code/contract provided by truffle unbox react

react.pragma solidity ^0.5.0;

contract SimpleStorage {
  uint storedData;

  function set(uint x) public {
    storedData = x;
  }

  function get() public view returns (uint) {
    return storedData;
  }
}

I call it like so,

  componentDidMount = async () => {
    try {
      const web3 = await getWeb3();
      const accounts = await web3.eth.getAccounts();
      const networkId = await web3.eth.net.getId();
      const deployedNetwork = SimpleStorageContract.networks[networkId];
      const contract = new web3.eth.Contract(
        SimpleStorageContract.abi,
        deployedNetwork && deployedNetwork.address
      );
      this.setState({ web3, accounts, contract });
    } catch (error) {
      alert(
        `Failed to load web3, accounts, or contract. Check console for details.`
      );
    }
  };

This is the function,

contract.methods.set(5).send({ from: accounts[0] });
const response = await contract.methods.get().call();

This is the new contract:

pragma solidity ^0.5.0;

contract SimpleStorage {
  string storedData;

  function set(string memory x) public {
    storedData = x;
  }

  function get() public view returns (string memory) {
    return storedData;
  }
}

And I call like so,

contract.methods.set("5").send({ from: accounts[0] });
const response = await contract.methods.get().call();

I get the following error

errors.js:85 Uncaught (in promise) Error: insufficient data for dynamicBytes length (arg="", coderType="dynamicBytes", value="0x000000000000000000000000000000000000000000000000000000000005", version=4.0.33)

What am I doing wrong?

Answer 1

With Web3 1.0, function arguments of type bytes and string must be converted to hexadecimal byte strings using web3.utils.asciiToHex().

Instead of contract.methods.set("5").send({ from: accounts[0] });,

execute: contract.methods.set(web3.utils.utf8ToHex("5")).send({ from: accounts[0] });