All Questions

0
votes
0answers
4 views

sent eth ropsten eth

sent eth on the 0xe2fcd50EfdD674C26f894aB5ad71fEcB14b7cDA4 / How to transfer them to eth ropsten wallet 0xAd9BA786b9692371E9DBDcCb8A51ff6ec94C6Fc0 ?can you the error?
1
vote
0answers
5 views

web3.eth.getAccounts() never resolves

I am attempting to connect the frontend of an application to a private chain through Metamask. As no web3 is injected, the following code is run const getWeb3 = () => ... ... ... ... const ...
1
vote
1answer
8 views

Realistically how often can I iterate a loop?

I realise looping is an anti-pattern, but I can't see a way round it. I'm maintaining an ordered list of addresses in a mapping. Separately there is a mapping of addresses to struct where I keep the ...
0
votes
1answer
5 views

Condition for changing a smart contract

I'm developing an application using smart contracts. I wonder if it is possible to establish different states for a contract, for example: User 1 determines a condition X, but also determines that ...
0
votes
1answer
6 views

converting uint256 to string

Any idea for the simplest way to add "degrees" variable into the string like below? Looking for getString to return "today is 40 degrees outside". pragma solidity ^0.5.3; uint public ...
0
votes
1answer
4 views

drizzle.contracts is empty object after creating new instance of Drizzle

After creating a new istance of Dirzzle and passing the needed options: const drizzle = new Drizzle(options); The object drizzle.contracts is an empty object instead of being an array of the ...
0
votes
1answer
4 views

Call `getPastEvents` with Drizzle raise error: “getPastEvents is not a function”

Calling getPastEvents with Drizzle will cause the exception: TypeError: this.drizzle.contracts.Contract.getPastEvents is not a function How to get all the past events in an array (in-one-shot) ...
1
vote
0answers
7 views

Why i cant see my balance in geth

I used that command for install my node geth console --rinkeby --datadir=~/.gophersland_ethereum_r1 --port=30304 --cache=6048 --rpc --rpcport=8546 --rpcapi=eth,web3,net,personal syncmode=fast After ...
0
votes
0answers
12 views

Transfer/Consult token of node ethereum

good morning. I need to implement an ERC20 token in an exchange from a client. I created a node ethereum and synchronized it, I created an ethereum wallet and sent some tokens for that wallet. By ...
2
votes
0answers
9 views

RPC Error with Payload when using the Ropsten Test Network Faucet with MetaMask

I'm trying to obtain some test ether from the Ropsten Test Network with Metamask, but I keep on getting an "RPC Error with Payload", whenever I try to click on "request 1 ether from faucet". I ...
0
votes
0answers
11 views

Metamask not being detected

I have written a simple application that takes in values from a form and uploads them to a blockchain, for all intensive purposes it works – the accounts are charged and the values are updated. BUT, ...
0
votes
0answers
19 views

Proper number of confirmations in a small testnet

In a private blockchain with just 4 miners, what should be the proper number of confirmations? 24 is by default, but does it make sense? should it be just 4 (one per miner)?
0
votes
0answers
18 views

How to calculate the value of mixhash in block header?

As of my knowledge how POW works is When mining the miner will have the hash1 which is block hash and he need to fine the hash2 which is hash of nonce (a random number). So that the root hash of ...
0
votes
0answers
12 views

Get the result back of a smart contract function call using INFURA

This is the function I use to send a signed transaction using Infura to invoke a smart contrac function (see details for the params of the transaction). web3.eth.sendSignedTransaction('0x' + ...
0
votes
1answer
17 views

How To Connect Web3 With MetaMask?

No tutorial can help me, I have watched almost every major tutorial on Youtube and read a ton of results from Google... I have on my HTML file imported the web3.min.js (copied from Truffle pet-shop ...
0
votes
0answers
18 views

Modify number of confirmations

By default there are 24 confirmations but I am running a testnet with just 3 miners and I would like to change this number bucause it makes not sense to have 24. I have been checking ...
0
votes
1answer
12 views

truffle migrate not working

every time I enter truffle migrate command in the terminal it doesn't does anything but takes some time and nothing happens after that. I am using Truffle version 5.0.4
2
votes
3answers
25 views

Why creating a private variable and a getter instead of just creating a public variable in solidity?

I want to implement a contract like the ERC20Detailed.sol example from open Zeppelin: My question: why setting a private variable and then, creating a getter for the same variable when the solidity ...
0
votes
1answer
22 views

Initial supply split into 2 hardcoded addresses with token allocation

don't know if someone can help me, but let me explain my problem. For more transparency in my token generation smart contract, I want to hardcode the Team Pool (0xA) and Crowdfunding Pool (0xB) with ...
0
votes
0answers
7 views

net.peerCount always 1

I've setup a couple of Main Network nodes on AWS and, for some odd reason, my net.peerCount never increases over 1. There are also periods when it falls down to 0 and the node lags behind. This is ...
0
votes
0answers
11 views

How to make smart contract call using INFURA and NodeJS web3js

I can not understand how I can prepare the transaction to be signed. Because INFURA does not support eth_sendTransaction but only eth_sendRawTransaction (INFURA API which then requires you to prepare ...
0
votes
0answers
10 views

Geth losing transactions

I have a couple of applications running on an Ethereum Blockchain hosted on a VM. For some reason, every now and then, I find my VM rebooted and the blockchain off. There's no problem in restarting it ...
0
votes
1answer
11 views

Specify different solc compiler for different files in truffle?

I am using truffle, and have a number of x.sol files in the contracts directory, different files require different versions of the compiler - how do i deal with that? I think i SHOULD be able to do ...
1
vote
1answer
20 views

ERC721 - How is gas worked out with TokenID?

ERC721 - I have minted a tokenid (tokenid=444) and my account owns it. When I try and transfer it, I get this message stating the gas cost is the normally calculated one and the total cost has the ...
0
votes
0answers
9 views

Hot to debug a contract method invocation?

Running this code: PrintProofOfWork.methods.printRequested(gcodeHash).send({from: web3.eth.defaultAccount}) .then((result) => { console.log(`result of the invocation: ${...
0
votes
1answer
10 views

Pass structures between contracts with Solidity 0.5

I'm trying to pass an instance of the Storage structure from StorageController.sol to Publisher.sol. No matter what I do, I get VM Exception while processing transaction: revert in my Truffle test. ...
1
vote
1answer
17 views

Check if a variable exists in external contract

kinda new to the development side of Ethereum. Been searching around for days but can't seem to find an answer for my specific case. I'm trying this challenge here. The problem is that I can't seem ...
0
votes
0answers
10 views

“SyntaxError: Unexpected token” on truffle develop

Once I run truffle develop this is the error I am getting. /usr/local/lib/node_modules/truffle/build/cli.bundled.js:33499 Config.search = (options = {}, filename) => { ^ ...
0
votes
0answers
9 views

Is there a way to download Remix IDE locally and access it from the Terminal (Linux)?

Is there a way to download Remix IDE locally and access it from the Terminal (Linux)? Hi, I think I have read that it should be possible to download Remix IDE and use it offline. In the latest ...
0
votes
1answer
18 views

Etherscan “Write Contract” Tab - what is it for?

What is the purpose of the Write Contract Tab in Etherscan? For example, if you look up the QTUM Token Contract on Etherscan (https://bit.ly/2IsddkT) and then tap on the Write Contract TAB, you have ...
0
votes
1answer
15 views

How I can generate a file.sol from ABI?

I have created an smart contract but the code in the sol file have disappeared. But the jeson file still remains. Can I generate my smartcontract again from ABI ?
2
votes
1answer
18 views

Ethereum HD address generator

I'm writing a library for Ethereum BIP44 address trees and comparing it against https://iancoleman.io/bip39/ using the same mnemonic phrase. Given this mnemonic (just a test) report dash combine ...
0
votes
1answer
12 views

web3 erroneously returning error

This is strange. My web3 script to deploy a contract seems to work, but always activates the .on('error', fcn) clause even though there is no error. The message says Transaction has been reverted by ...
0
votes
0answers
8 views

Swarm Formal Spec

Is there a formal spec for the Ethereum-Swarm protocol? I read the architecture section of the Swarm docs, but I think it's more of an overview. I need something with more notation, like the yellow ...
0
votes
0answers
15 views

ETH contract Integration to Website [on hold]

I am trying to add ThetherUSDT to my website (lang is c#). Could you please guys describe in short what i actually need to for hosting own wallet. I am running Geth on testnet. trying to integrate ...
0
votes
0answers
17 views

If nG and 2nG are known how to find generator point G [migrated]

if in a curve y2 mod p = x3+ 7 mod p ( ecdsa-secp256k1) p=115792089237316195423570985008687907853269984665640564039457584007908834671663 G=...
2
votes
1answer
20 views

Returns TX Object instead result in Truffle test

I'm getting AssertionError: expected { Object (tx, receipt, ...) } to be true Here is my testing code let apprOrOwnr = await this.erc721.isApprovedOrOwner(owner, tokenId); expect(apprOrOwnr).to....
1
vote
1answer
18 views

Is it possible to delete a completed transaction from your wallet history?

Is it possible to get rid of a completed transaction?
0
votes
0answers
11 views

How to interact with my Rinkeby contract via truffle console?

I've been using truffle console to interact with a contract which I developed locally with Ganache. I'd like to be able to call the contract's methods using the console once deployed to the Rinkeby ...
1
vote
1answer
8 views

What is the difference between approval and ownership in ERC721?

I saw the contract as getApproved and ownerOf functions. What is the difference between owning the token under ERC721 and having approval? When the tokenid is transferred does that transfer ownership ...
2
votes
1answer
27 views

How to use bignumbers in truffle tests?

I am testing a smartcontract with Truffle V5. All works well if I do not use all decimals. If I set 18 decimals all explodes. The test code is this (from truffle docs): const MetaCoin = artifacts....
0
votes
1answer
20 views

Options to install Ethereum nodes in a corporate environment

The main issue to install an Ethereum node in a corporate environment is the possibility to receive connection from unknown nodes. The security department is always concerned in open new doors to ...
0
votes
0answers
4 views

UnhandledPromiseRejectionWarning: AssertionError [ERR_ASSERTION]: The field to must have byte length of 20

I'm encountering a problem that I'm not able to solve. The code should launch a configured transaction with the details object. The current configuration is set to Ropsten and I am using the INFURA ...
1
vote
0answers
11 views

Geth crashes, “missing trie node”, rlp: expected List

I am struggling with failing geth with my Dapp. I got an error like this: Web3 UnhandledPromiseRejectionWarning: Error: Returned error: missing trie node ...
1
vote
2answers
34 views

“Self-destruct” use cases?

According to solidity.readthedocs.io (Link) here is the definition of Self-destruct: "Definition: The only way to remove code from the blockchain is when a contract at that address performs the ...
0
votes
2answers
13 views

Error converting wei using promises in NodeJS

I am running this code on NodeJS application: let destinationBalanceWei = web3.eth.getBalance(process.env.DESTINATION_WALLET_ADDRESS).then(result => result.toString()) let destinationBalance = ...
0
votes
0answers
3 views

drizzle not updating events properly - duplicate events

I'm facing a peculiar problem while rendering event values in a component using drizzle. When a new event is created and is updated in the events array of drizzle (drizzleState.contracts.MyContract....
0
votes
1answer
22 views

Transaction pending

If I call this function the transaction get pending and never finish. Any idea? pragma solidity ^0.4.24; contract test { uint[] values = [1,2,3,4,5,6]; function removeValueFromArray(uint _num) ...
0
votes
1answer
17 views

ParsedContract.sol:1:17: ParserError: Token incompatible with Solidity parser as part of pragma directive

Code : git clone https://github.com/dappuniversity/election https://github.com/dappuniversity/election/tree/2019_update Errors faced : Commands: Compile: truffle compile Migrate: ...
0
votes
0answers
13 views

Truffle Deployment

I have created a DAPP using Truffle & Ganache. It is working fine in development server after running the following command. $ganache-cli Deploy the contract. $truffle migrate --reset Run the ...

15 30 50 per page