Questions tagged [ethereumjs]
For questions regarding the installation or use of EthereumJS, a Javascript library that implements a number of Ethereum utility functions.
346
questions
0
votes
1answer
20 views
How to parse ecrecover parameters?
I am looking into getting the public key from ANY ethereum address (not owned by me) that has sent a transaction at least once. It seems that the most viable solution here would be to use ethereumjs-...
0
votes
0answers
17 views
ethereum hash is not searchable in parity private network
I did this in rospten network, but when I use it in private parity network, I get transaction hash, but it isn't searchable at the explorer:
const Web3 = require('web3');
const EthereumTx = require('...
1
vote
2answers
34 views
I Call SmartContract Token ERC20, Why Show Hashing Output ? (Web3 + Metamask + Javascript)
I do not know why with this, even though in the previous version (web3 + Metamask) can issue real data. But now used as hashing (output). I took the example in the code and output below (to get the ...
0
votes
3answers
60 views
How to build a decentralised Voting Website without using any 3rd party extensions like Metamask, or IDEs like Remix? [closed]
I've gone through various Blockchain Tutorials but everywhere it's one or the other same thing. Download truffle/ganache, from 10 free testrpc account, use one, use metamask, Remix IDE etc, and Voila!...
0
votes
0answers
39 views
Transactions go to an older contract address rather than the present deployed one
Though I have deployed a new contract but the transactions go to a previously deployed contract in my application. I'm attaching the screenshot of my Remix-ide code and the code for the front end ...
0
votes
1answer
99 views
problem connecting web3 v 1.2.1 with metamask : 'currentProvider' of undefined
I am using Web3 v1.2.1 with nodejs v10 and following this link. I am having issue connecting with metamask,below is my code snippet:
const Web3 = require('web3')
const window = require('window');
...
0
votes
1answer
24 views
Code:const web3 = new Web3(window.web3.currentProvider) Error: window.web3 is undefined
I am going to connect my contract with the website.However,there was something wrong with the web3? I'm not sure.
import Web3 from "web3";
const web3 = new Web3(window.web3.currentProvider);
const ...
1
vote
1answer
56 views
Which version of web3 shall i be using now?
I found the documentation of version 1.0.0 which was released on the 6th of August here. I was told that v1 is not stable and very different than earlier versions. But when i check the available ...
0
votes
3answers
39 views
transferFrom function not working in ICO Smart contract
I am facing issues with the transferFrom function of smart contract address 0x6560a9b6436e129cf835ab9da96201207facd4f8:
I copied the smart contract code from etherscan.io and deployed on ropsten ...
1
vote
1answer
42 views
How do I use web3js 1.0.0 in geth 1.9.0? I want to import an account whose address, private key and passphrase I have in my geth node [duplicate]
I am at Geth/v1.9.0-stable-52f24617/linux-amd64/go1.11.5
web3JS version is giving :
> web3.version
{
api: "0.20.1",
ethereum: "0x2712",
network: "4",
node: "Geth/v1.9.0-stable-52f24617/...
0
votes
0answers
22 views
Error: Keystore: Must include seedPhrase in createVault inputs. How to fix?
i'm studying blockchain development, and i'm trying to create wallet with seed words using eth-lightwallet and vuejs. But i receive this error: Keystore: Must include seedPhrase in createVault inputs, ...
2
votes
0answers
22 views
What is the difference between signing a document, signing a transaction and signing a message? (very basic)
As per my limited knowledge in Ethereum, user can sign the object(doc, Tx, msg) for the security purpose and with the public key other user can get that object.
But not understand the difference ...
0
votes
0answers
30 views
How do I perform a fully anonymous transaction using Stealth addresses in Aztec protocol?
I want to know how to make use of Aztec's stealth address protocol.
0
votes
0answers
16 views
Can I Create Node.js API for each function in Smart Contract but sign a Transaction from frontend via Metamask.?
I am trying to develop a Dapp with nodejs backend but I cannot get accounts from Metamask which resides on my frontend.
I tried to create an endpoint for each function in Smart Contract. And it seems ...
2
votes
1answer
26 views
How to know in advance the gas used by a transaction?
I want to send an ERC20 token (Ropsten network). So I execute a function 'transfer' on a contract. When The transaction is sent, I can get the gas used in the receipt. Few months ago this amount was ...
0
votes
0answers
15 views
Is there a way to broadcast/send transaction using web3js using token that is not ethereum?
My question is: I am trying to send a transaction using a cryptocurrency very similar to ethereum, in fact their code is almost copy pasted from ethereumjs:
https://github.com/CSEPlatform/cse-tx/blob/...
0
votes
1answer
59 views
'ALERT: Trying to call a function on a non-contract address' Why Do I Keeping This Error?
This is the error from metamask directly:
This is the error I get once after I submit the information to IPFS:
My Smart Contract:
pragma solidity 0.5.3;
//Imports for safe math operations
import "...
0
votes
1answer
27 views
Why txHash in sendSignedTransaction giving Undefined value on sending on rinkeby testnet
let Tx= require('ethereumjs-tx').Transaction;
const Web3= require('web3');
const url='https://rinkeby.infura.io/v3/d4dbc79ea192404fb42689cc55ce2fc0';
const web3 =new Web3(url);
const account1= '...
0
votes
0answers
24 views
Error using drizzle and react
My contract Storage.sol -
pragma solidity ^0.5.0;
contract Storage {
string public data;
function getData() view external returns(string memory) {
return data;
}
function setData(...
0
votes
0answers
13 views
Error send token
let minABI = [
// transfer
{
"constant": false,
"inputs": [
{
"name": "_to",
"type": "address"
...
0
votes
0answers
14 views
How to save contract address to database with web3js and mongoose when I deploying a contract?
I wanted to get my contract address after it deployed, and then save it into my mongoDB. But instead of that, my contract address is deployed after it. So my mongoDB won't save my contract address. ...
0
votes
0answers
30 views
which is a better method to use for signing messages between two parties in web3?
I have been searching for a while for the most secure and supported way for off-chain channel messaging.....so i was using web3.eth.sign(address, keccak256(msg)) for singing messages ....but then used ...
0
votes
1answer
64 views
How to use window function in controller (node.js)?
So this is my users controller to upload a file :
exports.postUploadFile = (req, res, next) => {
var ethereumURI = req.body.ethereumURI;
var abi = JSON.parse(req.body.abi);
var ...
0
votes
1answer
83 views
Error when testing the contract
ApprovalContract.sol
pragma solidity ^0.5.1;
contract ApprovalContract{
address public sender;
address payable public reciever;
address public constant approver=...
0
votes
1answer
26 views
Do smart-contracts work as APIs?
Is it possible to put a smart contract "behind" a restful API, i.e. expose my contract functions and properties through restuful API where I can make RPC to it?
Or does it work as an API already, but ...
1
vote
3answers
139 views
comparing two addresses
I'am trying to create a modifier that allows certain accounts to execute functions.
address[] authorized;
function verify (address adrs) internal view returns (bool)
{
bool exist;
...
1
vote
1answer
37 views
ENS name reverse is not working on Ethereum address
I'm trying to both resolve and lookup using "ethjs-ens" the lookup call is working correctly. However, the resolve call is throwing an empty error.
The address I'm using on the reverse function is ...
2
votes
2answers
30 views
Troubleshooting a revert on Ropsten
I’ve deployed a contract to Ropsten and am testing it manually with Remix. This transaction reverts for whatever reason (we have unit tests where everything looks fine).
In our contract for all of ...
1
vote
2answers
35 views
Contract.deployed() does not work as expected
I use Truffle to test a contract. When i use Contract.deployed() and i fetch address, for example :
In a first test, the contract's address is
0x07D899846146b3503dE9D9Dc36B94C2e428eA434
In a second ...
0
votes
0answers
11 views
Oraclize : Calling more than one API independently [duplicate]
There are 2 API 's which has to be called in different time delays recursively.
For example : API_1 = 20 mins delay and API_2 = 24 hr delay.
How can we call the above 2 API's independently based on ...
1
vote
0answers
13 views
Oraclize ethereum bridge : Notifying __callback tx error to frontend
I have called API dynamically using Oraclize with the delay of 10 minutes. The code is shown below and it works well.
uint256 constant DELAY = 60*10;
event Log(string result);
function ...
1
vote
1answer
52 views
where does the metamask fits in Dapps architecture?
i am learning building Dapps. And i got to know to know about metamask.
I've read about metamask is an ethereum wallet which we can use to sign Tx's without running a full node and inject web3 to ...
0
votes
2answers
41 views
Cannot declare web3 object in JavaScript
When I try to declare a web3 object It's always undefined.
I'm writting in JavaScript and using Infura as my provider for the ETH mainnet. I also tried with a local blockchain instead of Infura, but ...
0
votes
1answer
52 views
How to call setter method of smart contract with web3 1.0.0
I don't know why but i'm not able to perform transaction with this code.
please help me out i'm stuck. i just have to call setter method of my contract with some arguments.
router.post("/set", async ...
0
votes
0answers
24 views
Web3js v0.20.7 - callback ls not a function
I'm facing issue of callback is not a function in web3js 0.20.7 when i call the method of sendRawTransaction to deploy smart contract with web3.
When i used the same method just to call deployed ...
0
votes
1answer
66 views
How to use bip39 module in angular?
I am trying to create an ethereum wallet app using Ionic. I have tried to import bip39 node module directly in the angular project but it gives me error. Please help
import { Injectable } from '@...
0
votes
1answer
22 views
connecting geth to web3.go 1.0 via websockets or HTTP
Is there anyThing similar to web3.js written in go that allows me to communicate with the geth client ?
1
vote
0answers
24 views
How to do loop all the metamask Accounts loop and display data from that address in React frontend + Dapp App JS [duplicate]
I want to Display data stored on the Ropsten Network in more then 2 metamask accounts.
I want to display the result on the Home page in the table form.
For that I need to loop through each ...
0
votes
1answer
39 views
how do etherscan get all the token balance of particular address?
I want to create service where just by providing address i can fetch all the token (erc 20 & erc721) balance just like etherscan for a private network?
is there any way to do it by writing for ...
0
votes
1answer
114 views
How to deploy Smart Contracts With Web3 Using Async/Await?
This is my Javascript code. I keep getting an error that states
Error: No privateKey given to the TransactionSigner.
at TransactionSigner._callee$ (/Users/payton/WebstormProjects/Esgro_DAPP/...
0
votes
0answers
62 views
Web3 Websocket Connection To Infura Rinkeby Ropsten
This is my Javascript code. I keep getting an error that states
(node:30062) UnhandledPromiseRejectionWarning: TypeError:
privateKey.startsWith is not a function
I am using node 12.1.0 & ...
2
votes
1answer
47 views
How to create a private ethereum network [closed]
I want to understand how to create a private blockchain using ethereum and create a minable coin. Also, I want to know if I can modify the consensus algorithm that runs on every node?
There are ...
0
votes
1answer
101 views
Why Could not find artifacts for contract from any sources
I am using windows 10 with truffle and ganache-cli. I have 2 contracts file to be deployed contain interfaces of other contracts defined within the contract:
Contracts:
ERC721Mintable.sol
Ownable
...
1
vote
1answer
234 views
Web3 - Cannot read property 'clearSubscriptions' of undefined
While creating a web3 instance, and attempting to call setProvider with a valid provider (Ganache), I get a TypeError.
TypeError: Cannot read property 'clearSubscriptions' of undefined
Steps to ...
0
votes
1answer
60 views
How do I deposit Ether to Smart Contract using Web3.js
So I am creating a web application that interacts with a smart contract that I deployed on the Ropsten TestNet.
I am able to withdraw ether from the contract to my Metamask account using a withdraw ...
0
votes
0answers
26 views
getting an error while deploying smart contract of ethereum
I am getting an error while trying to deploy smart contract of voting dapp on ethereum
I have searched for the solution for the same and i got a question with same problem but there no solution. ...
2
votes
2answers
447 views
How to connect with public Ethereum Blockchain on a backend/web server?
In the backend of a Web application I have to communicate with the public Ethereum Blockchain.
On local development machine, I run ganache as testrpc and connect with such a line of code:
web3 = new ...
0
votes
0answers
47 views
How can I comparing fingerprint using solidity language?
I have a fingerprint image stored in IPFS and I want to compare with another fingerprint image, because i need to know if is the same fingerprint ,is there some way, some lib that i can compare this ...
0
votes
1answer
57 views
Can I create & run test cases for smart contract without truffle?How?
does truffle is necessary for smart contract testing?
Is there any alternative way, so that we can perform smart contract testing without truffle?
0
votes
2answers
78 views
msg.sender in contract is empty
I have the following deployment script
var contract = web3.eth.contract(response.abi);
var bytecode = response.bytecode;
var options = {
from: ...
