Convert HTML input in ether to wei to send to smart contract

Question

I want my clients to fill in a number in ethers instead of Wei (as I don't what them to go through the hassle of putting 18 zeroes in every time.)

I'm trying to do this in the following way in JavaScript, but for some reason, it triggers the transaction, but translates the amount 1-1 into wei (so input 1 gives 1 wei instead of 1000000000000000000 wei.)

$("#BetalenRekeningMI").click(function() {
  contractMI.testmultiinput(web3.toWei($("#bedrag").val(), 'ether'),
                            $("#addressMI").val(), {value: 0},
                            function(err, result) {
                          console.log(err, result);
                            })
});

Here some more details. This is the corresponding HTML (without the comment tags of course:

      <tr>
        <td>
          <input type="text" name="bedrag" id="bedrag" placeholder="Bedrag in Ether"/>
          <input type="text" name="addressMI" id="addressMI" placeholder="Adres van de leverancier"/>
          <button id="BetalenRekeningMI">Klik hier om te betalen</button>
        </td>
      </tr>

This is the Solidity function that the JS triggers:

 function testmultiinput(uint256 bedrag, address klant) payable{
        klant.transfer(bedrag);
    }

Answer 1

I suggest you test your code with another Ethereum implementation, or update your copy of Ethereum.

You convert Ether to Wei correctly.

Here are some examples of using the toWei() function of web3.

web3.toWei(1)
"1000000000000000000"
web3.toWei('1')
"1000000000000000000"
web3.toWei('1.1')
"1100000000000000000"
web3.toWei('1.1', 'ether')
"1100000000000000000"

Your code works correctly for me. I entered '1' and an address of '0x00' into your web form:

and the Parity signer received 1,000,000,000,000,000,000 wei to send to your contract:

I have a master version of Parity that is a few weeks old, with these version strings:

>
11:58:56.081
web3.version.api
<
11:58:56.089
"0.17.0-alpha"
>
11:59:02.934
web3.version.node
<
11:59:02.947
"Parity//v1.7.0-unstable-02f2c61-20170711/x86_64-macos/rustc1.18.0"

Answer 2

Here some more details. This is the corresponding HTML (without the comment tags of course:

<tr><td><input type="text" name="bedrag" id="bedrag" placeholder="Bedrag in Ether"/><input type="text" name="addressMI" id="addressMI" placeholder="Adres van de leverancier"/><button id="BetalenRekeningMI">Klik hier om te betalen</button></td></tr>

The corresponding js is above and this is the solidity function is triggers:

 function testmultiinput(uint256 bedrag, address klant) payable{
        klant.transfer(bedrag);
    }

Answer 3

I had the exact same issue and it can be easily solved by converting the value parameter in the transfer method to ether.

See below for example:

destinationAddress.transfer(value * 1 ether);

Note the multiplication by 1 ether, without which the transfer will be done in default type Wei.

Hope this helps.