Missing data parameter ?

[remiroyc]

Hi,

In your encodeEthSend() function, I think you forgot to set data parameter in default mode.

ethereum:<address>[?value=<value>][?gas=<suggestedGas>][?data=<bytecode>]

const encodeEthSend = (data) => {
  const fromBlock = isValueDefined(data.from) ? `?from=${data.from}` : '';
  let valueBlock;
  if (isValueDefined(data.value)) {
    const weiValue = new BigNumber(data.value).toString(10);
    valueBlock = isValueDefined(data.value) ? `?value=${weiValue}` : '';
  }
  const gasBlock = isValueDefined(data.gas) ? `?gas=${data.gas}` : '';
  return `ethereum:${data.to}${fromBlock}${valueBlock}${gasBlock}`;
};

If you wish I can try to propose a pull request for that.

[mezrin]

@Reminouche , hi
That was done intentionally

Currently supported URI scheme: ethereum:<address>[?from=<sender_address>][?value=<ethamount>][?gas=<suggestedGas>]. This used to send ETH between accounts.

If you need to invoke specific method of the contract - please, see this part of readme: https://github.com/jibrelnetwork/ethereum-qr-code#2-invoke-function-of-a-contract

What is the reason to support [?data=<bytecode>]?
I can imagine only one use-case - when you want to deploy a new contract.
But this is not a purpose of QR code :)

[remiroyc]

Yea i saw your invoke function feature, but imagine :

I have a web application wich needs to pass some parameters to ether contract.

If user interacts with your contract via a qr code, there are no problems (user passes data with function parameters).

But if he wants to send a transaction directly from a eth wallet (online web wallet for example), it is a little bit complex for a user to format a correct json into data message field. I think it could be easier for him to send hexacode directly in data.

[mezrin]

We miss something

QR code used to transfer info between two apps.
This is the only purpose of the QR code.
I.e.:

• you have an app A1 which needs to invoke a contract
• this app A1 packs needed info to invoke a contract
• another app A2 manages your private keys
• app A2 receives packed info, unpacks it, signs transaction, sends the transaction to the network

Generally, you can use anything to pack data. A text file will work just fine.
But we use QR code because it is handier for end-user.

The user is not able to interact with the contract via QR code.
User does not need to create json - data should be combined with the app A1

If you develop app A1 and need to pass some data to the contract - just use field argsDefaults.
You can set any value to the function argument there

Real use case: you come to the shop and want to buy bread with some TOKEN

• cashier creates a receipt for 5 Euro
• cashier creates QR code to send 100 TOKEN to his account
• you scan QR code with the smartphone
• app on your smartphone reads data from the QR code and creates an interface to send tokens
• you check encoded data (receiver address, number of tokens) and confirms a transaction
• app on your smartphone combines transaction and sends it to the network

As I see, there is no place for compiled data parameter...

[mezrin]

Also, I do not know about widely used Ethereum wallets that support QR codes and data parameter. Most known Ethereum wallet and myetherwallet do not support QR codes at all...

[shershen08]

Closing for now, since there was no activity on this issue for 3 days.
@Reminouche feel free to reopen if you have further proposal.