How to call my contract's function using sendRawTransaction?

Question

I am trying to call my contract's method using sendRawTransaction. I have a function in my contract

updateReading(address consumerAddress,
            uint32 consumerMeterId,
            uint64 consumedReadingValue,
            address producerAddress,
            uint32 producerMeterId,
            uint64 producedReadingValue)

which I want to call using sendRawTransaction. The updateReading function updates the contract state of the contract. How can I make a call to this function using sendRawTransaction?

I am using truffle framework for the development.I have written the following code in my js to call the function using sendRawTransaction.

        var privateKey = new Buffer(password,'hex')
        var setData;
        var contractAddress;
        EnergyTrade.deployed().then(function (instance) {
              contractAddress=instance.address;
              setData=instance.updateReading(consumerAddress,consumerMeterId,consumedReadingValue,producerAddress,producerMeterId,producedReadingValue);

              var rawTx = {
                    to:contractAddress, 
                    from:consumerAddress,
                    data: setData
                  }


              var tx = new Tx(rawTx);
              tx.sign(privateKey);

              var serializedTx = tx.serialize();
              web3.eth.sendRawTransaction(serializedTx.toString('hex'), function(err, hash) {
                    if (!err)
                      console.log(hash); 
              });

        })

It returns the following error in my console.

    (node:23336) UnhandledPromiseRejectionWarning: Error: invalid type
at Object.exports.toBuffer (/home/maria/Desktop/12-Energy/node_modules/ethereumjs-util/dist/index.js:177:13)
at Transaction.setter [as data] (/home/maria/Desktop/12-Energy/node_modules/ethereumjs-util/dist/index.js:625:19)
at /home/maria/Desktop/12-Energy/node_modules/ethereumjs-util/dist/index.js:685:63
at Array.forEach (<anonymous>)

Another issue is

   (node:23336) UnhandledPromiseRejectionWarning: Error: invalid address
at inputAddressFormatter (/home/maria/Desktop/12-Energy/node_modules/truffle-contract/node_modules/web3/lib/web3/formatters.js:271:11)
at inputTransactionFormatter (/home/maria/Desktop/12-Energy/node_modules/truffle-contract/node_modules/web3/lib/web3/formatters.js:97:20)
at /home/maria/Desktop/12-Energy/node_modules/truffle-contract/node_modules/web3/lib/web3/method.js:89:28
at Array.map (<anonymous>)

How can I make sendRawTransaction possible in my js using truffle framework?

Answer 1

As the error message says, Truffle doesn't have a getData method, but from my reading of the code, I believe you can access the underlying web3.js contract object via the contract member. Try this instead:

setData=instance.contract.updateReading.getData (consumerAddress,consumerMeterId,consumedReadingValue,producerAddress,producerMeterId,producedReadingValue);

Answer 2

Problem in your code is instance.updateReading() in this line. Web3js will treat as a direct function call(sendTransation or call()) based on your original abi. i.e it will not create bin or hex string.

I am not very sure about getData() method. As per web3js, you can use encodeABI() this method will return bytecode.

Simply you can append your

setData = instance.updateReading(consumerAddress,consumerMeterId,consumedReadingValue,producerAddress,producerMeterId,producedReadingValue).encodeABI();

For more details please refer below link

https://web3js.readthedocs.io/en/1.0/web3-eth-contract.html#methods-mymethod-encodeabi

https://github.com/ethereum/wiki/wiki/JavaScript-API#web3ethsendrawtransaction