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My ERC20 token dapp is giving an error only while using 'transfer function' even when I am using a given address as defaultaccount ( otherwise the error was "No "from" address specified in neither the given options, nor the default options.").

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<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>My TOKEN</title>
    <script src="https://cdn.jsdelivr.net/npm/web3@latest/dist/web3.min.js"></script>
    <script src="https://code.jquery.com/jquery-3.5.1.slim.min.js" crossorigin="anonymous"></script>
    <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/css/bootstrap.min.css" integrity="sha384-Vkoo8x4CGsO3+Hhxv8T/Q5PaXtkKtu6ug5TOeNV6gBiFeWPGFN9MuhOf23Q9Ifjh" crossorigin="anonymous">
</head>
<body style="background-color:powderblue;">

<div class="container-fluid">

  
    View Total Supply  <br><br>

  <div class="form-row">

      
    <div class="form-group col-md-2">
    <button id="button" onclick="viewtsupply()">View Total Supply</button><br>
    </div>
    
    
    <b><div id="viewtotalsupply" ></div></b>
    <br>
  </div>

    View Balance <br><br>

  <div class="form-row">

    <div class="form-group col-md-2">
    <input  type="text" id="balanceOf_param1" placeholder="Wallet address">
    </div>

      
    <div class="form-group col-md-2">
    <button id="button" onclick="balanceOf()">Check Balance</button><br>
    </div>
    
    
    <b><div id="viewbalanceof" ></div></b>
    <br>
  </div>

  
    TRANSFER MyToken <br><br>

  <div class="form-row">

    <div class="form-group col-md-2">
    <input  type="text" id="transfer_param1" placeholder="Transfer To">
    </div>

    <div class="form-group col-md-2">
    <input  type="text" id="transfer_param2" placeholder="Amount">
    </div>
    
      
    <div class="form-group col-md-2">
    <button id="button" onclick="transfer()">Transfer</button><br>
    </div>
    
    
    <b><div id="viewtransfer" ></div></b>
    <br>
  </div>


    <script type="text/javascript" src="./abi.js"></script>
    <script type="text/javascript">

    var MyToken;
    const web3 = new Web3(new Web3.providers.HttpProvider(
    'https://ropsten.infura.io/v3/1a831534f602458bac682c5a0c797e37'
    ));
    
    $(document).ready(function(){
      window.addEventListener('load', async () => {
        // Modern dapp browsers...
        if (window.ethereum) {
            window.web3 = new Web3(ethereum);
            try {
                // Request account access if needed
                await ethereum.enable();
                // Acccounts now exposed
                web3.eth.sendTransaction({from : web3.eth.defaultAccount});
            } catch (error) {
                // User denied account access...
            }
        }
        // Legacy dapp browsers...
        else if (window.web3) {
            window.web3 = new Web3(web3.currentProvider);
            // Acccounts always exposed
            web3.eth.sendTransaction({from : web3.eth.defaultAccount});
        }
        // Non-dapp browsers...
        else {
            console.log('Non-Ethereum browser detected. You should consider trying MetaMask!');
        }
      });
      var accounts = web3.eth.getAccounts();
      //web3.eth.defaultAccount = web3.eth.accounts[0];
      web3.eth.defaultAccount = `0xe50938d856B57954D06be1a1525A8141aF40ECD2`
          const address = '0x429BfaeC81eB7e282b6cbc28d3aa2baCE04C382A';
        MyToken = new web3.eth.Contract(abi, address);
      });

        
      async  function viewtsupply(){
            
            const result = await MyToken.methods.totalSupply().call()
            .then (function (result){       
                $("#viewtotalsupply").html('<b>Total Supply is : </b> :'+ JSON.stringify(result));
                console.log(result);
            });
        }
    
        async  function balanceOf(){
            var p2 = document.getElementById('balanceOf_param1').value;
            const result = await MyToken.methods.balanceOf(p2).call()
            .then (function (result){       
                $("#viewbalanceof").html('<b>MyToken Balance. </b> :'+ JSON.stringify(result));
                console.log(result);
            });
        }
    
        async function transfer(){
        var p1 = document.getElementById('transfer_param1').value;
        var p2 = document.getElementById('transfer_param2').value;
        
        const result = await MyToken.methods.transfer(p1, p2).send({from:web3.eth.defaultAccount, gas:1000000})
        .then(function (result) {
         $("#viewtransfer").html('Transfer sucessful <br>From : ' + (result.events.Transfer.returnValues._from) + '<br> To :    ' + (result.events.Transfer.returnValues._to) + '<br> of MyToken Amount: '+ (result.events.Transfer.returnValues._value));
        console.log(result);
        });
        }
        
</script>
  </body>
</html>

Please help in decoding both the errors.

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1 Answer 1

Reset to default
0

Here is the answer to your problems:

  1. web3.eth.defaultAccount is deprecated in modern dapp browsers and that's why you get missing from property error. You can read more how to solve this here.
  2. Method eth_sendTransaction is not supported by the Infura provider.

Why your reading methods are working and the transfer method is not? Because for reading the blockchain your don't need private keys and transactions submitting, but you need them for updating the blockchain. And since Infura does not hold private keys they cannot sign transactions instead of you ( read more here ).

You need to sign the transaction with the private key and then submit it to the blockchain. You can achieve that by using method sendSignedTransaction.

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