Questions tagged [ethereum-wallet-dapp]

Tag for the questions related to the deployment of the contracts using Ethereum wallet.

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votes
4answers
2k views

address.transfer not working

pragma solidity ^0.4.23; contract ApprovalContract { address public sender; address public receiver; address public constant approver = 0x5AEDA56215b167893e80B4fE645BA6d5Bab767DE; constructor() ...
0
votes
3answers
728 views

Error from Remix: “ParserError: Expected primary expression”

This is my code: pragma solidity>0.4.99<0.6.0; contract Election { struct Candidate { string name; uint voteCount; } struct Voter { bool authorized; bool voted; uint vote;...
2
votes
2answers
147 views

Golang Equivalent to list accounts on node - web3.eth.Accounts()

Does anyone know if its possible to get a list of the accounts on a node using golang, after Dialing to the node, basic PoC would be assuming the accounts are already unlocked via the CLI Basically ...
5
votes
3answers
2k views

Transfer from contract address

I created a contract with a payable function but the ether is stored in the contract I am looking for a way to transfer the ether to another address
0
votes
1answer
161 views

Getting “Contract Compilation failed” error

I am trying to run my first contract and getting this error "Contract Compilation failed". pragma solidity >=0.4.0 <0.6.0; contract SimpleStorage { uint storedData; function set(uint x) ...
1
vote
1answer
143 views

What is the difference between writing emit in an event and not using emit? [duplicate]

For example, event CoinTransfer(address sender, address receiver, uint amount); What is the difference between CoinTransfer(msg.sender, receiver, amount); and emit CoinTransfer(msg.sender, receiver, ...
1
vote
2answers
307 views

Can a payment be made automatically from a smart contract?

If I have two people who want to make a payment at a certain time, eg 1pm tomorrow for 1 ETH, can a smart contract perform that task without the payer stating their private key at the time of the ...
1
vote
1answer
35 views

How to setup a DOMAIN name for my project? [closed]

I have created one project by writing samrtcontracts and web3api . NOW i want to deploy my code into live using domain name .so that all the users can use it. How can i deploy my code into live and ...
2
votes
0answers
43 views

What is a suitable pattern for building a web/mobile app that leverages ether? [closed]

Noob to ether dev. Looking to understand how to build an app that leverages Ethereum - what suitable patterns are out there (ideally to go via some tutorials). A few apps examples (from easy to ...
1
vote
0answers
15 views

Backup The Ethereum Wallet Account names

As you know, the keystore folder stores account keys. So if I want open my accounts(which was created by Linux client) by MacOS client I need just copy the keystore folder. But in this way my ...
2
votes
1answer
358 views

Metamask Warning

In an effort to improve user privacy, MetaMask will stop exposing user accounts to dapps by default beginning November 2nd, 2018. Dapps should call provider.enable() in order to view and use accounts. ...
1
vote
3answers
73 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
219 views

Escrow account creation in the example ICO contract from openzeppelin

I am understanding the ICO as explained in openzeppelin https://github.com/OpenZeppelin/openzeppelin-solidity/tree/master/contracts/examples When I called the "Buy tokens" the beneficiary is getting ...
0
votes
2answers
529 views

Truffle : dotenv is not working in truffle.js

I am trying to get the seed words from the powershell command prompt. Hence I am using the 'dotenv' in truffle.js require('dotenv').config(); console.log('aa - process.env.MNEMONIC : '+mnemonic); ...
1
vote
0answers
886 views

Issue in installing truffle-hdwallet-provider

I am trying to install "truffle-hdwallet-provider" using the command "npm i truffle-hdwallet-provider --save". I am getting the beow mentioned error. Please assist me in resolving this. truffle-...
1
vote
1answer
364 views

What are different between peers and remote in ethereum wallet?

I run ethereum wallet on my Windows 10 PC, sometimes it displays "1 peers", and sometimes it display "remote", would you please see the image? What are different between peers and remote in ethereum ...
1
vote
0answers
20 views

Wallet files in a Dapp

I am developing an application from the truffle webpack and I have created my own wallet, adding my account to a json file: $.getJSON('../wallet.json', function(data) { var password = "xxx"; ...
0
votes
1answer
48 views

Unable to Generate Address Endpoint Blockcypher

I am trying to generate an address using Blockcyphers Address Endpoint using cUrl. - https://api.blockcypher.com/v1/eth/main/addrs?token=eth But it returns this error - "Endpoint not found. Please ...
2
votes
1answer
325 views

web3.js new accounts without local node!

I am trying to develop an dapp, but since I am running a small server (Windows Sever 2012 R2) with limited space I don't want to host/install an ethereum node, nor geth in my server, because as many ...
0
votes
1answer
408 views

Truffle Develop Could not find suitable configuration file

Basically, after I installed the truffle the command: nom truffle -g . Then I went to set up the metamask on the google chrome. Once the metamask is set up then I try the command: truffle develop and ...
1
vote
1answer
38 views

Unknown wallet address on private development chain

Apologies in advance for the long post. I'm new to Ethereum and don't know which details are significant and which are not. I'm trying to learn about dapps by following an example in this book. My ...
0
votes
1answer
71 views

Estimation of gas in web3js 0.20

Q:- While sending only Ether One wallet to another wallet(NO SMART CONTRACT), do we need to define the default gas limit and price? i.e. 21000 * 3 OR 21000 * 4 OR 21000 * 5 etc Or I've need to use ...
0
votes
1answer
202 views

How to map multiple time and index value on same address

I wish to map the time to the address key. But currently it is working on the index key only. I just want to map time as well. Means the current time. So that I can able to get the record with time as ...
1
vote
1answer
147 views

Input byte array must be in range 0 < M <= 32 and length must match type-web3j

I have created an api to addCandidates. But when i run the api i get error: Input byte array must be in range 0 < M <= 32 and length must match type My codesnippet for addCandidates is: @...
0
votes
1answer
49 views

acess variable from token contract to ico contract , both placed in diffrent files

//token.sol pragma solidity ^0.4.24; /*import "./Ownable.sol"; */ contract ERC20Interface { function totalSupply() public constant returns (uint); function balanceOf(address tokenOwner) ...
0
votes
1answer
197 views

How to read previous blocks data?

I'm new to block chain technology. I'm trying to store and read blocks using testRPC along web3.js. I'm able to get the latest block data but not able to fetch previous blocks data. Please some one ...
0
votes
1answer
305 views

Uncaught Error: CONNECTION ERROR: Couldn't connect to node web3.min.js:1 http://localhost:8545

**Hi, I am doing a sample project on Ethereum where 2 fields ( Emp name, Emp Id) will be taken from the UI and set those values using a smart contract and show the values back to UI. Getting below 2 ...
1
vote
1answer
50 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
2answers
105 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
138 views

How get the private key using web3js?

is it possible to get the private key of ethereum wallet using web3js? I want to encrypt data using the ethererum keys?
0
votes
1answer
194 views

Infura API for mobile(ionic) app

I have one little question. Suppose I have private key of user in ionic app. Is this enough to make transactions using infura API and web3?
6
votes
2answers
2k views

Login system for DAPP without metamask

I'm building Dapp on Ethereum. Imagine I have companies to register in my dapp, I will provide them with their own smart contract and public and private key pair, which they will use to just unlock ...
1
vote
1answer
205 views

Golang How to slice Ethereum log events from smart contract to a more readable format

Im looking to use a channel to watch contract log events but the output returns a byte array like this the go code i am using looks like this package main import ( "...
1
vote
0answers
43 views

Case study : Blockchain as a service [closed]

I have a web application which has DynamoDB as the database. I want to store some SCORE in a DynamoDB table. How can I restrict this SCORE to only some set of people in my web application can modify ...
2
votes
0answers
54 views

Can one store short text data when transacting ERC20 tokens? [duplicate]

I am having trouble understanding if i can store short pieces of text when I send an ERC20 token. I have successfully stored a small message when transacting ETH by converting it to HEX and adding it ...
3
votes
0answers
24 views

Ethereum wallet accounts all use same password though I made different ones?

(tech level, beginner) installed wallet version win64-0-11-1 deployed a contract, made a token using the example code on ethereum site. had two accounts in the wallet. used main account to send ...
2
votes
1answer
195 views

msg.sender is Null in Base Constructor

When I create the child class object and try to access value of msg.sender from parent class it always comes 0. Can anyone please help me in this? Below is the sample code: contract Test1 is Test2 { ...
-2
votes
2answers
155 views

My Private key from myetherwallet.com was stolen, Can I add more steps to access my wallet?

yesterday I was cheated by this MEW address user:0x83ecb676706aa5c7cf72384723935dd1195dcb3e He/She sent my 0.2549 Eth from my ETH Wallet address :0xe6b0d7f7d18c14015d47ecc77cf5c0009f34bb18 Shit!!! ...
1
vote
1answer
153 views

Installing Ganache GUI on windows 8.1

How to install Ganache UI on windows 8.1 ? I downloaded from Official website but after downloading i am unable to install it on my machine. I tried to install it through power shell but facing ...
2
votes
2answers
200 views

How do I update data for project using blockchain (Ethereum)?

I am very new to creating blockchain dapps, so some guidance would be appreciated. I am conceptualizing how to approach creating a private blockchain so that users can communicate about the status of ...
1
vote
0answers
81 views

Insufficient funds for gas * price + value Etherum Wallet

Version: `0.11.1` OS & Version: windows Node version: `geth 1.8.13` Number of blocks synchronized: 55 Private network I am testing with Ethereum Wallet using the private test network created by ...
1
vote
1answer
248 views

How to encrypt file before storing into IPFS network in Javascript? [closed]

I want to encrypt file before storing into IPFS network so that only person who is uploading a file should be able to decrypt.
3
votes
2answers
745 views

How to use mnemonic to recovery my ethereum wallet

I use web3j to create my ethereum wallet.the Code just like down import org.web3j.crypto.Bip39Wallet; import org.web3j.crypto.Credentials; import org.web3j.crypto.ECKeyPair; import org.web3j.crypto....
2
votes
2answers
193 views

First Time Ethereum Wallet User Setup Questions

I will try to make this a fast post with just a few questions I cannot figure out the answers to: I am trying to accept/send ETH payments and have downloaded, installed, and created a wallet using ...
1
vote
0answers
32 views

How can I implement ethereum If I'm making an exchange service like cex.io [closed]

I was wondering how cex.io manages ethereum service on their website. I know what happens with bitcoin. They have 1 wallet and daemon on their server for each coin. for example bitcoin. Then When I ...
0
votes
1answer
54 views

How to create withdraw token requests on my custom token sale dashboard

I created a token sale dashboard. Users can send BTC,LTC,ETH to dashboard. When user send BTC, LTC or ETH to dashboard, they get tokens to their dashboard budget (offchain) based on current token ...
1
vote
2answers
259 views

How to get all index value?

contract Bar{ struct Foo{ uint x; } mapping(uint => Foo[]) foo; function add(uint id, uint _x) public { foo[id].push(Foo(_x)); } function get(uint id, ...
1
vote
0answers
23 views

How to interconversion between privatekey and keystore with password in interactive console

When I execute geth attach attaching a active geth node into a interactive console . I could use keystore and password to sendTransaction . But now I only know the raw privateKey,How to execute ...
0
votes
1answer
79 views

Ethereum unlock account

Is there any way to unlock the ethereum account when using the infura api. Can only metamask do it? I would not like to use metamask because not every user has it on the browser
1
vote
0answers
136 views

creation of Hourglass errored: transaction execution failed

I don't know why I'm getting this error while deploying 2 of my contracts. creation of Hourglass errored: transaction execution failed while code compiles successfully no issues there. ...