Questions tagged [ethereumjs]
For questions regarding the installation or use of EthereumJS, a Javascript library that implements a number of Ethereum utility functions.
1
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0answers
5 views
Signing a transaction with uport can't approve as the selected account can't change.How can i change in uport selected account?
I am developing a dapp with uport verifications but when i goes for saving a information into ropsten network. a uport signing transaction is apear on my screen and i can't approved the transaction.
...
0
votes
0answers
9 views
Building Data Stream Market Place on Ethereum
I want to build a Data Stream Market Place based on Ethereum Like Streamr.
There will be two kind of users, Sellers who can upload their Data Streams through API and Buyers who can purchase the ...
0
votes
1answer
27 views
How to sign on ethereum a pdf like on this video? [on hold]
How to sign on ethereum a pdf like on this video?
I'm asking specifically about what happens at 00:40 where you have a user
uploading the file and then it get stored and cryptographic signature is ...
0
votes
1answer
31 views
Web3 Rinkeby Infura Problems
I've got a Smart Contract that works perfectly when deployed to localhost: 8545 (using Ganache) with my Web3 Dapp. But when I put it on Rinkeby, I'm running into problems,.
The Contract is super-...
0
votes
2answers
56 views
What is the best practice for a tax payment Smart Contract?
I have just been introduced to Ethereum Smart Contracts and I have a faculty-related project that implies the usage of them.
The idea is to create a DApp which allows clients (persons) pay taxes (in ...
0
votes
1answer
36 views
How long does it take to sync Rinkeby network with geth?
I am syncing the Rinkeby network with geth
geth --rinkeby --rpc --rpcapi="personal,eth,network,web3,net" --ipcpath="~/.ethereum/geth.ipc"
When I run
eth syncing
in geth console, it is showing
{
...
0
votes
1answer
12 views
Script to automatically transfer ether to another address
Please, can anyone help with a script to use and watch my address for any incoming ether, and once it enters, the script would quickly transfer the ether to another address.
I would also love to know ...
0
votes
0answers
22 views
Crypto and Assert modules missing? [closed]
I try to test the Ethereumjs-wallet library on a react native project, but it seems the crypto and asset modules are missing.
Here's the code I try to start :
import React, {Component} from 'react';
...
2
votes
0answers
21 views
How to listen for Metamasks “Taking too long? Resend with higher gas!” option from web3js?
Just ran in to an issue with Metamasks "Taking too long? Retry with higher gas!" option
Basically, when I am sending a transaction to my contract, I are performing some db interaction upon receiving ...
1
vote
1answer
37 views
MetaMask breaking change - does ethereum.enable() prompt an Access signature every time it's called?
Does ethereum.enable() prompt an Access signature every time it's called?
Or will access-granted status persist?
1
vote
3answers
37 views
What is Metamask?
I know it's a dApp web3 browser, a wallet. But which ethereum client is used in the back end to interact with block chain? How the same account is able to connect with all networks (mainnet,testnet, ...
1
vote
2answers
24 views
How to setup 'topics' for function getPastLogs ()?
Sir,
I want to read the past event log by using getPastLogs()，but I got the whole log.I hope I can filter some log.
I find I can setup the 'topics' in getPastLogs(),but it always fails. How ...
1
vote
1answer
16 views
Send eth from one account to another using transfer() function
I am trying to write a smart contract that will send eth from one account to another account :
Contract Send {
event Sent(address from, address to, uint amount );
function send(address _receiver,...
0
votes
0answers
21 views
Getting better error messages from MetaMask on FireFox?
Currently, if a user denies the consent message or is not logged in to MetaMask and attempts a transaction between the dApp and MetaMask, Chrome provides a rather descriptive error message like:
Error:...
0
votes
1answer
18 views
About getPastLogs usage
"getPastLogs" can get past event log. I check the web3 documentation：
fromBlock - Number|String: The number of the earliest block ("latest" may be given to mean the most recent and "pending" ...
0
votes
0answers
10 views
How to get past event log by Node.js?
I want to read past event log.
My Node code is:
const Web3 = require('web3');
const ethereumUri = 'http://192.168.2.17:8545';
let web3 = new Web3();
web3.setProvider(new web3.providers.HttpProvider(...
0
votes
0answers
16 views
How to pass 'uint' argument to deployed smart contract from web3.js?
In my smart contract, I have a method
function addPerson(uint _age, string _name) public payable {
// some operation
}
From my node application, using web3.js library, I am trying to ...
0
votes
2answers
37 views
Sending Signed Transaction returns pending and event:undefined
I am trying to send a signed transaction using web3 1.0 and Infura.io through the browser. When I run it I dont get any errors but the transaction never hits the blockchain so I am confused on whats ...
0
votes
0answers
14 views
Error: invalid remainder
I want to use MetaMask for signing transactions on frontend and send them from backed, but got error, while sending signed transactions:
Error: Returned error: invalid remainder.
// Backend on ...
0
votes
3answers
25 views
how to generate mnemonics from randombytes
I am able to get the randombytes using react-native-crypto-js
const words = CryptoJS.lib.WordArray.random(32);
Is that possible to generate mnemonics using random bytes.
0
votes
0answers
34 views
How to generate mnemonics in react native
I would like to generate 12 word mnemonics in react native. Can any one help me how to generate mnemonics in reactnative.
0
votes
0answers
30 views
Uncaught Error: CONNECTION ERROR: Couldn't connect to node http://localhost:8545
Testrpc is running.. getting error
Uncaught Error: CONNECTION ERROR: Couldn't connect to node http://localhost:8545.
Because of the code.
web3.eth.accounts[0];
0
votes
1answer
44 views
Error: Cannot find module 'ethereumjs-wallet'
A truffle test needs ethereumjs-wallet
const wallet = require('ethereumjs-wallet');
I tried
npm install ethereumjs-wallet
and even
npm uninstall ethereumjs-wallet
npm install --save ethereumjs-...
0
votes
0answers
22 views
failed to connect Localhost/Infura
I am trying to access a smart contract method through web3.js, but while a request, i am getting a following error in the console.
web3.min.js:1 Failed to load
https://rinkeby.infura.io/v3/...
2
votes
1answer
43 views
Different address with single mnemonic phrase
I'm trying to implement ethereumjs-wallet library to my code.
But when I decided to compare generated accounts with accounts generated with the same mnemonic here, I got absolutely different accounts, ...
1
vote
0answers
39 views
Unable to deploy smart contract to rinkeby using ledger wallet?
I am trying to deploy smart contract using ledger wallet. But i keep getting the error cant subscribe to new header. However i get the transaction hash but cant receive the contract instance and ...
0
votes
1answer
39 views
How to state private keys when using node.js and ethereum to run a contract?
I have to run node.js to execute smart contracts. My quetsion is about the keys.
I have seen this from the docs -
1. Code to sign
2. Code to execute
But I am unsure how the two are combined. Could ...
0
votes
0answers
29 views
How do I connect multiple clients to Ganache?
How do multiple clients interact with the same webpage using Ganache? Right now, I can get it to where it uploads a document for one client and displays the document on the screen on a private ...
0
votes
0answers
21 views
Error in test file in vscode file not found
With truffle 4.0.5 on windows, test files fail to "import" with error:
Error
ParserError: Source "truffle/Assert.sol" not found: File not supplied initially.
import "truffle/Assert.sol";
ParserError:...
2
votes
0answers
44 views
Mnemonic and HD Path in Ganache and ethereumjs-tx gives different private key and address
I am having difficulty reproducing the private key and address using the mnemonic and HD path provided by Ganache.
Mnemonic
weird farm vast surge upper truth answer end radar impact mind jeans
HD ...
0
votes
0answers
11 views
Is it possible to query ethereum blockchain event logs using nodejs & infura client
I have a contract deployed on Ropsten testnet.
From our backend side , I want to use nodejs to query event logs stored in contract.
event TokenDelivered(address indexed receiver, uint256 amount);
...
0
votes
0answers
18 views
Getting Addresses using a Path causes the error: Could not derive hardened child key
I am using ethereumjs-wallet npm package to generate a unique wallet address for each user. However instead of using the mnemonic/seed, a public extended key xpub will be used instead to keep the ...
1
vote
0answers
27 views
How to integrate ledger wallet in REACT DAPP? [closed]
i cant seem to find a way to integrate ledger wallet in react DAPP. Like which library to use. Any kind of guidance and starting material would be helpful.
Thank You
0
votes
1answer
34 views
Deployment of Blockchain Dapp application on cloud!
I have my dapp in progress using PrivateNet, Metamask, HTML, CSS, JAVASCRIPT & Solidity in Ethereum. After the finishing of my application I just wanted to host my application on cloud. As of now ...
1
vote
2answers
85 views
solidity ecrecovery and ethereumjs ecsign return different address
I have a code as follow using web3 0.2 and ethereumjs-util to interact with smart contract. What exactly am i doing it wrong? is it incompatible between ecsign of ehtereumjs with smart contract ...
1
vote
0answers
73 views
Metamask create transaction with popup prompt
Im trying to create a basic static html page to send a transaction using metamask. It looks like web3 is not being injected into the page at all even though i have metamask installed.
I would have ...
0
votes
1answer
106 views
Deploying contract with arguments using raw transaction
I want to deployed to deploy the following contract that has a constructor with the following arguments.
contract test{
constructor(address _recipient, address _user){
...
}
}
I want ...
1
vote
1answer
58 views
Connecting with existing ganache core server
I have a ganache-core server running at port 18545 (part of an npm app)
How can I attach to it and see the transactions/blocks in that. I tried running ganache GUI and setting port number as 18545 in ...
0
votes
1answer
29 views
Solidity smart contract interacting with deployed smartcontract
Below are the steps (take note, no issues when I test this on remix, it works absolutely fine)
Two smart contracts, Usermapping.sol and CoffeeNetworking.sol
in truffle "2_deploy_contract.js" enable ...
0
votes
0answers
48 views
Truffle interacting with deployed contract on private blockchain
In truffle unable to interact with deployed contract but no issues on Remix browser.
Below are the detail steps
Usermapping.sol is first contract, compiled and deployed, no issues.
Contract address ...
0
votes
1answer
176 views
Web3 js 1.0 is throwing big number error while transfering tokens
When I tried to transfer more then 1000 tokens, it's throwing an error like as mentioned below (I'm using web3 js 1.0.0 34 beta version).
Error: [number-to-bn] while converting number 1e+23 to BN....
1
vote
1answer
23 views
Allowing multiple polling for user
Is there a way to allow user to vote for multiple proposals.
For example:
User A can vote for proposals :P1,P2,P3,etc.
Once A has voted for P1 he should not be allowed to vote for P1 but is eligible ...
0
votes
1answer
46 views
Unable to Generate Same Account from MetaMask Mnemonic in EthereumJSWallet
I've been unable to generate the Account I see in MetaMask in EthereumJSWallet even if I use the same mnemonic.
Due to the lack of documentation, I may be misunderstanding how to do so.
I have run ...
0
votes
2answers
24 views
Require validation error not working
I tried using require method in solidity in the following way:
require(validate(personName),"Error: Invalid Person")
In this case i am checking if a person is already added to my person list. If not ...
0
votes
1answer
18 views
solidity error, while accessing struct value of an array of nested mapping of deployed contract
Remix Error: Type error, Return argument type inaccessible dynamic type is not implicitly convertible to expected type (type of first return variable) bytes32[].
snippet code shown below: Do take note ...
0
votes
1answer
30 views
solidity interaction with a struct mapping of a deployed smart contract
I have followed the below code as follows on remix and it works fine but i have an issue when i try to access one of the struct value of a key.The last line of the code doesnt work.
pragma solidity ^...
0
votes
1answer
198 views
getting error nonce too low , but nonce is proper stuck since one day
I am working with web3.js since sometime now , but now i am stuck with nonce too low error , the nonce is proper also i have checked private key and other addresses , they also seem to proper , ...
1
vote
2answers
22 views
Convert array with hex datatype to readable format using truffle console
I am new to ethereum. I am using truffle to develop, deploy and interact with my solidity contract.I have a function in my contract which is as follows:
function getResult(bytes32 name) public view ...
0
votes
1answer
27 views
Store N key value pairs
I have a scenario where I need to store N no. of document hashes in a smart contract with some key(id). And also fetch the particular document hash by it's key. Any help on designing the structure for ...
4
votes
2answers
153 views
Difference between public private and consortium blockchain
I am new to blockchain therefore i am trying to understand difference between private public and consortium blockchain. I do understand public blockchain but i am unable to differentiate between ...
