Questions tagged [web3js]
Javascript API and library for Ethereum To develop applications on Ethereum, you can use the web3 object provided by the web3.js library. Under the hood it communicates to a local node through RPC calls. web3.js works with any Ethereum node, which exposes an RPC layer. https://github.com/ethereum/wiki/wiki/JavaScript-API
3,407
questions
3
votes
2answers
2k views
Web3 create account from mnemonic + passphrase
I'm trying to create an ethereum account using web3-js by providing a mnemonic + passphrase (created with BIP39-js) but can't seem to find an implementation of web3.eth.accounts.create() that accepts ...
0
votes
1answer
23 views
Error: Invalid JSON RPC response: “” from web3
I run:
geth --rinkeby --rpc --rpcport=8545 --rpcaddr=192.168.1.37
It works in console:
geth attach http://192.168.1.37:8545
> eth.syncing
false
> eth.accounts
["...
0
votes
1answer
21 views
Invalid sender address, failed to deploy a transaction to the blockchain network
Description
I'm trying to deploy a contract to rinkeby network, but everytime I like to deploy the contract it throwing error as invalid sender.
Compile code
const path = require('path');
const fs =...
0
votes
1answer
15 views
TypeError: market.FileViewed is not a function while trying to watch event
I want to watch for fileViewed event and it throws TypeError: market.FileViewed is not a function in
marketplace.FileViewed{
^
My solidity contract:
pragma solidity ^0.5.0;
contract ...
0
votes
2answers
24 views
invalid number value for power of 18
Using web3js v1.2.1
const contract = new web3.eth.Contract(abi, '0x29...');
const amount = 1 * 10 ** 18;
const data = contract.methods.transfer(recipient, amount).encodeABI();
I get error :
invalid ...
1
vote
1answer
162 views
Handling require/assert failure errors correctly from a Node.JS app?
I have a getter function in my smart contract that returns one of the string values in statically defined string array. Upon entry to the function, it does a bounds check on the incoming index using ...
1
vote
3answers
1k views
Estimate Gas Price (not Gas) using Web3
Using Web3, we are able to estimate the amount of gas needed for a transaction
let estimatedGas = web3.eth.estimateGas({
to: "0x11f4d0A3c12e86B4b5F39B213F7E19D048276DAe",
data: "...
26
votes
5answers
5k views
How to detect if an address is a contract?
I'm interested in knowing whether any particular address is a contract address or a standard address. There have been similar questions on the topic, but I'm not looking to detect whether an address ...
0
votes
0answers
17 views
getPastEvents undefined(please help)
I had asked this question before. I looked carefully at the exchange section, which I advised, and I think there is no problem with the exchange section. At least in my opinion there is no problem and ...
4
votes
1answer
152 views
Can't debug transactions that fail during the Web3.js estimateGas() call? No Tx Hash
NOTE: I am doing my work with the Ganache v1.2.2 GUI client on a Linux Ubuntu 18.04 station.
There are many revert errors that happen during the estimateGas() call that precedes the actual Web3.js ...
2
votes
1answer
195 views
Connecting to blockchain on azure using web3.js and websocket
right now, I am trying to write a service using web3 which will 'subscribe' to all 'perndingtransactions' on blockchain to perform further actions. web3 documentation says that 'Httpprovider' cant be ...
0
votes
1answer
199 views
Transaction stuck in 'Pending' state when using 'sendSignedTransaction'
I am trying to execute a transaction by first signing it with my private key using ethereumjs-tx and then using sendSignedTransaction to send the transaction to the network. But somehow the ...
0
votes
3answers
996 views
How do I get the return value of a solidity function with web3?
The docs mention using
MyContract.methods.myFunction().call().then(console.log);
but methids methods I get the error then I get the error that the function is undefined.
The code below doesn't ...
1
vote
1answer
201 views
Error: Node error: {“code”:-32015,“data”:“Reverted 0x”,“message”:“VM execution error.”}
I deployed my smart contract on Kovan Etherium testnet. After that, I am trying to interact with smart contract methods using web3 1.0.0. Below is my node js code:
var Web3 = require('web3');
var api ...
0
votes
2answers
151 views
Intracting with dapp using frontend truffle petbox
App = {
web3Provider: null,
contracts: {},
account: '0x0',
init: function() {
// Load pets.
return App.initWeb3();
},
initWeb3: function() {
if (typeof web3 !== 'undefined') {...
0
votes
1answer
138 views
read error unexpected EOF
I'm working a evidence application with quorum.I want to store the entire contents of a file on my private blockchain. Although it's not recommended. At first I use a linux command 'split' cut a big ...
0
votes
0answers
13 views
Trying to send ERC20 token with Javascript button without success
I am trying to send an ERC20 token with the following code via web3.js. It was working until a week ago and then it stopped. Am I doing something wrong? Upon clicking it no longer interacts with ...
0
votes
1answer
196 views
How to retrieve data form a smart contract?
Following is the contract that I want to call, and retrieve the string in node.js. But I want have a require that allows only some specific address to have this data.
pragma solidity ^ 0.4 .4;
...
1
vote
2answers
2k views
Create an Ethereum wallet with React Native for single token
Many of you might think that this question has already been answered
but I don't think that there is a clear answer on the internet for the
current Ethereum, Web3.js and React Native versions (for ...
0
votes
1answer
142 views
Deploy bytecode
I have a compiled contract (actually it's just arbitrary data) that I would like to store as an account.
It is possible to store this as a new account using web3js?
I do NOT have a constructor ...
0
votes
1answer
13 views
Call functions from another account by default in web3
In my truffle tests, I am trying to call a function from an account other than the default account, so not accounts[0] from the below result. web3.eth.defaultAccount doesn't seem to work.
web3.eth....
0
votes
1answer
27 views
Verifying if a user actually owns the address
Web3js frontend with Vue, .NET Core with Nethereum at the back.
The key target for this functionality is to sign a message at the frontend, send the signature and the address to the backend to ...
1
vote
1answer
19 views
Creating a contract instance
Is it generally better to define a contract instance once, then pass it through your components like...
class Parent extends React.Component{
constructor(props){
super(props);
...
0
votes
2answers
990 views
SyntaxError: await is only valid in async functions and async generators in web3js [on hold]
Below is my code snippet. I wish to wait for the transaction hash value so that I can return my Javascript function with the hash value.
But I get the error "SyntaxError: await is only valid in ...
0
votes
1answer
77 views
Unhandled promise rejection (rejection id: 1): Error: Transaction has been reverted by the EVM:
I don't know where i'm doing mistake. I have deployed my contract through remix and truffle and it was deployed without any mistake but now i'm deploying it from web3 solc@0.4.24 version and EVM is ...
1
vote
1answer
146 views
Can the Android Metamask Extension be used with DApps?
I've successfully downloaded the Metamask Firefox Add-on, and imported my wallet into it.
However I'm failing to see how I can use this add-on from within my DApp like I do on Chrome, using the ...
1
vote
1answer
31 views
Duplication of events in permissioned geth Chain with clique PoA consensus algorithm
I have an Ethereum chain running on my local host via geth and i am using the clique PoA Algorithm. I have 4 authority nodes so the number of Nodes allowed to sign a block should always be 1 because ...
0
votes
1answer
99 views
Unlocking account web3.js 1.0 on AWS Lambda
I'm getting following error message when trying to unlock account on AWS Lambda:
Error: Node error: {"code":-32601,"message":"The method personal_unlockAccount does not exist/is not available"}
...
0
votes
1answer
102 views
Web3js can not touch smart contract, always return 0
web3js can not touch smart contract.
var id = dragoncore.getGenesNum(); has no error, but always return back 0, never changed.
-----------------------------web3js code -----------------------------
...
2
votes
1answer
263 views
subscription not happen on geth+websocketProvider in web3
I have started geth node (connect to ropsten testnet) on my local OSX system.
Command: geth --testnet --fast --bootnodes "enode://...
0
votes
1answer
167 views
Web3js :interact with smart contract
I'm currently struggling to interact with my smart contract, I don't if it comes from the way I call the function or the way I connect to my smart contract. Here is the code
const contractAddress = '...
0
votes
0answers
14 views
cloning div container number of deployed child contracts time and put their data inside div container
Sorry for the silly question. I have a div container "product-card" , I want to loop the number of my deployed smart contracts time. every time when I loop I want to clone this div container and ...
0
votes
0answers
8 views
How can I change the text message on connection request window of metamask?
I want to change the message in connection request window using web3js.
I have attached screenshot here. kindly check it.
1
vote
2answers
26 views
How do i use .send() to fire methods of my smartcontract?
I have looked alot for information about this and lastly i turn myself to here. I've written a smartcontract and deployed it to Ropsten . I am then using web3.js to interact with my smartcontract, i ...
1
vote
1answer
135 views
Merkle proof for Smart Contract mapping field data
I'm trying to get merkle proof for Ethereum Smart Contract mapping field data.
I created test smart contract and deployed to test network.
Smart Contract Code like following code:
contract ...
0
votes
1answer
132 views
Unable to send ether to account
I am trying to send ehter using this code
web3.eth.accounts.wallet.add(privateKey);
web3.eth.sendTransaction({
to:someAddress,
from:onwer,
value:amount*1,
...
0
votes
1answer
409 views
Creating a transaction from a webform - invalid number of args
I have a HTML web page where I am feeding user entries into a smart contract that is designed to "store" the entries in transactions. I have most of the application working, but I'm having trouble ...
0
votes
0answers
36 views
erc20 transfer SafeMath: subtraction overflow?
I am trying to transfer a erc20 token.
const data = contract.methods.transfer(recipient, amount).encodeABI();
const rawTx = {
from: sender,
nonce: '0x' + count.toString(16),
...
1
vote
1answer
148 views
Ropsten rejects my sendSignedTransaction function
This is my code:
contractNoEvents.methods.myMethod().call(function(err,foo){
if (foo.length > n) {
contractNoEvents.methods.myOtherMethod().call(async function(er, bar)...
0
votes
1answer
159 views
The contract code couldn't be stored, please check your gas amount while deploying contract
I'm trying to deploy 3 contract in 2_deploy_contract (I deploy all 3) but after the first is deployed I get the following error : The contract code couldn't be stored, please check your gas amount.
2
votes
4answers
2k views
How do I install web3@1.0.-beta.26 on Windows 10?
How do I install web3@1.0.-beta.26 on Windows 10? npm install --save web3@1.0.0-beta.26 does not work and creates a page of errors.
I've also tried --python=python2.7
Here is what I get.
C:\Users\...
0
votes
0answers
19 views
Parity Aura - Error: Transaction has been reverted by the EVM
I run the following code against two private blockchains, parity-aura and geth-clique. Why does the parity transaction revert and why does it use 6,000,000gas when it should actually only use about ...
0
votes
1answer
55 views
metamask and web3: Invalid number of arguments to Solidity function
my function has only one input string description :
function createProposal(string description) {
Proposal memory p;
p.description = description;
proposals.push(p);
}
and ...
0
votes
1answer
199 views
Ganache not working
I am developing on a testnet on ganache and using remix.
I am working with web3 and working on the user interface.
when trying to fetch a function with web3/ganache, I get the following error:
"...
1
vote
1answer
122 views
are truffle tests inconsistent?
Im currently testing my contract and I've written truffle tests in js for the first time. Rarely (1 out of 10 times?) I get unexpected results:
This is the code structure I use:
var contract = ...
1
vote
1answer
612 views
Error: Returned error: invalid sender
I'm trying to sign transaction and send it to remote node, but I keep getting this error:
UnhandledPromiseRejectionWarning: Error: Returned error: invalid sender
This is how I perform signing and ...
0
votes
1answer
117 views
Can't connect to localhost:8545 while using ethereumjs-testrpc web3?
I am developing a simple Voting dApp by following a tutorial. In this tutorial
we are using npm install ethereumjs-testrpc web3 so that we can get the fake nodes of Ethereum.
For that i first ...
0
votes
0answers
16 views
Ethereum payment processor Nodejs
I'm working on a web project where I need to have the ability to accept crypto payments. Implementing bitcoin was fairly easy as there were api's whom allowed me to directly subscribe to a specific ...
1
vote
0answers
54 views
Error while installing web3@1.0.0-beta.26 on Windows 10
I am getting the following error while installing web3@1.0.0-beta.26 on Windows 10.
npm ERR! code ETARGET
npm ERR! notarget No matching version found for web3-core@1.0.0
npm ERR! notarget In most ...
0
votes
1answer
602 views
Sending ether to a contract
Beginner in solidity and i'm trying to send ether from an address to a contract. I've tried transferring ether using the Remix compiler test accounts.
pragma solidity 0.4.25;
contract sendether{
...
