Questions tagged [react]

React (also known as React.js or ReactJS) is a JavaScript library for building user interfaces. It uses a declarative paradigm and aims to be both efficient and flexible.

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Drizzle component returns BigNumber

I am using the following Drizzle (Truffle) component to call a function from a smart contract: <ContractData contract="Market" method="priceOf" methodArgs={this.props.id}/> The result is a ...
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1answer
266 views

How to get the returned value of a smart contract function when it called by using cacheSend() in drizzle

I just tried to build a simple DApp using truffle, react and drizzle. My question is how to get the returned value of a smart contract function when it called by using cacheSend() in drizzle? As ...
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1answer
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npm ERR! code ENOENT npm ERR! syscall spawn git

I use the command npx truffle unbox react to develop a dapp but I get these errors below in my console. Can anybody help me? I really don't know how can I solve them.
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Help me fix Error: No “from” address specified in neither the given options, nor the default options. I'm use MetaMask

file web3.js import Web3 from 'web3'; const web3 = new Web3(window.web3.currentProvider); export default web3; file image.js import web3 from './web3'; const address = '...
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1answer
520 views

Truffle unbox drizzle not working properly

truffle version = 4.1.4 truffle unbox drizzle truffle compile truffle migrate npm run build npm run start this gets me this error: Truffle Drizzle-box fails with TypeError: (0 , _drizzle....
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8 views

Any idea how to add new contracts into drizzle react app using the address?

I have a react app which creates new contracts. lets say A creates B. I have the addresses of the newly created contracts of B. How do i add the newly created contracts of B using its address to ...
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1answer
12 views

Display matrix in React

I am trying to return a matrix in React that I get from a contract function. This is the function that resonate the matrix: int[][] public publicData; function handleAddData(int[] memory ...
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1answer
277 views

Unhandled Rejection (Error): invalid string value (arg=“x”, coderType=“string”, value=5)

Using Truffle unbox react to unbox a boilerplate. received the following error from running npm run start Changes: Addition of "memory" parameters in the simpleStorage.sol Changed unit to string in ...
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1answer
84 views

this.contract.deployed() is not a function

I'm working on making a React frontend for my smart contract, but I'm having problems connecting it into my React code. Here are the relevant portions of my code: import TruffleContract from '...
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1answer
315 views

gyp ERR! stack Error: `C:\Program Files (x86)\Microsoft Visual Studio\2017\BuildTools\MSBuild\15.0\Bin\MSBuild.exe` failed with exit code: 1

I used the command truffle unbox react to build a dapp. It is just the initial step of my dapp development. However, it sucks. It continually pops up gyp ERR! build error gyp ERR! stack Error: `C:\...
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1answer
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How do I fix it? To be able to send eth from smartcontract to the address

Frontend class App extends React.Component { state = { address: '', } async componentDidMount() { await window.ethereum.enable() this.w3 = new Web3(window.ethereum) const ...
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1answer
11 views

How can I add new contracts generated from a factory to my drizzle-react app?

I have a Factory contract which creates new contracts. How do I get the new contract into my drizzle-react web app? I am using to send the transaction to create a new contract but I don't know how ...
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How do I get the value from the event to be displayed on the webpage? [duplicate]

I can connect and console.log the event. But can't bring the value to display on the webpage. I don't know what to do. Front-end import React from 'react'; import logo from './logo.svg'; import './...
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29 views

What do I have to do to call this events to be display on the web page?

How do I call showLottery to display on my webpage? Front-End class App extends React.Component { state = { address: '', lottery: '', events: '', } async componentDidMount() { ...
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1answer
73 views

Dapp cannot fetch a string

Somehow i cannot get any result from my backend solidity. i have asimple dapp that takes firstName from input field save in blockchain and then fetch it back and display it on the screen. state={ ...
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1answer
124 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 ...
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1answer
35 views

Contract with multiple signing keys

How things work I have a Factory contract, FContract. FContract can be called by a user as many times as they want, creating instances of, let's call it, contractA. Thus, they're able to own as many ...
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2answers
117 views

No “from” address specified in neither the specified in neither the given options nor the default options

So I already went through this query, but I still couldn't get my doubt solved. Be it any Blockchain Dapp, the same error is coming for me. I used the marriage certificate and kickstart examples. Can ...
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2answers
119 views

Metamask injects one account in web3, but calls contracts using another account

Building a React app, MetaMask injects web3, I get accounts[0] from getAccounts(), then pass it to my contract functions together with other parameters. I want my modifiers to lock incoming function ...
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1answer
29 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 ...
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0answers
24 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 ...
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1answer
1k views

The send transactions “from” field must be defined!

I am trying to call a function of a contract that has been deployed to Ganache. I am trying to call a function that makes payouts to a few addresses and can be called by owner only. When I am calling ...
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0answers
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Is there any example of a drizzle-react dapp implementation that uses render props?

Render props were added after React 16.3 and the github readme for drizzle-react suggests to use them. The problem for is that there is no updated documentation (other then the small example in the ...
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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 ...
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1answer
21 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); ...
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0answers
24 views

“drizzle-react-components” import Error for “LoadingContainer”

I am trying to import import { LoadingContainer } from 'drizzle-react-components' Which I succfully installed with npm install drizzle-react-components@1.3.0 It was installed inside the directory ...
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1answer
79 views

web3-core-method.umd.js:1191 Uncaught (in promise) Error: Transaction has been reverted by the EVM:

Keep getting this error and really not sure what's causing it. Smart contract: contract BasaltStore { // struct of how a document will be stored struct documentStore { // unique id of the ...
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1answer
740 views

Drizzle cacheCall is not updating data correctly

I have a react component which is interacting with a solidity contract via drizzle. I store a cacheCall index in the constructor: this.opcTokenCacheCallIndex = context.drizzle.contracts.OPCToken....
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1answer
363 views

How to get only past 2 days events using getPastEvents everytime?

How can the following query be modified to only fetch the past two days worth of events: const events= await MyContract.getPastEvents("eventName", { fromBlock: 0, toBlock: "latest" });
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1answer
103 views

Event emits multiple times on a solidity function call

I need have a problem, when I execute a solidity function, event emits multiple times, but when I refresh page then it works normally and only past events get called. Here is my code: ...
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0answers
15 views

How can I specify a date picker in one of the fields in my ContractForm React component?

I'm using the ContractForm React component available in the drizzle-react-component library. It's super nice and easy to setup and use, but I am dealing with a date in one of the fields (which is ...
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3answers
2k views

Accessing web3 object in Chrome terminal using React

I am receiving a "not defined" error when trying to access the web3 object in Chrome terminal. My current setup: running testrpc web3 object successfully instantiated in App.js built app using React ...
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1answer
74 views

Both web3.eth.accounts.create() and web3.eth.personal.newAccount() not working

I'm making a dApp on reactjs. I wanted to create a new account and have done it trying 2 methods this.web3.eth.personal.newAccount() this.web3.eth.accounts.create() I have attached the code below(...
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3answers
141 views

Why web3.eth.getAccounts().then(console.log) return empty array?

It's really weird that I got empty array after I tried to web3.eth.getAccounts().then(console.log);and I also got a warning which is ./node_modules/web3-eth-accounts/src/scrypt.js Critical dependency: ...
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1answer
36 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 ...
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1answer
76 views

Web3-core-helpers error: Uncaught (in promise) Error: Provided address “undefined” is invalid,

When I launch the app with with react.. this error occur when my exchange contract is loaded.. Here is the code i wrote to talk to the blockchain: export const loadBalances = async (dispatch, web3, ...
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2answers
722 views

Truffle migrate no error but does not create build directory

I'm trying to develop a simple dapp using ReactJS.I used Charterhouse/truffle-create-react-app box suggested by truffle website. The problem is truffle compile and truffle migrate do not seem to work. ...
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1answer
422 views

Accessing Web3 in trufflebox's react-auth-box

Hi I am using trufflebox boilerplate react-auth-box. Created a new component called Foo where I am trying to access the web3 object that has been mapped from Store to this.props. However the console....
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2answers
13k views

TypeError: Cannot read property 'then' of undefined

I am having an error with Web3. After going through all possibilities I decided to post a question hoping for someone with a solution. The error I keep getting is: TypeError: Cannot read property '...
2
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1answer
72 views

Uncaught (in promise) Error while opening and doing transaction on private ethereum blockchain using web3 and go-ethereum

I am trying to integrate a react app with go-ethereum using web3js. an event Onsubmit will do the following: 1. Create an account. 2. Open the account. 3. Approve a smart contract with the created ...
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0answers
25 views

Error: IPFSInbox has not been deployed to detected network

It's my first time writing smart contract in solidity and using IPFS to develop my dapp. I don't know how to solve it and why it pops up this errorNo web3 instance injected, using Local web3. Error: ...
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0answers
31 views

Payable function not working properly

Hi everyone hope I will be clear enough with the explanation because I couldn't find a proper solution. I am just trying to checkout an item with my buy function but it seems like I am stuck.Here is ...
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1answer
94 views

Why Web3 event callback fires multiple times same as the number of the solidity smart contract emitted that event in past?

I am just learning, solidity with react and web3 and I am facing the issue on page load the callback event of web3 called multiple time the number is same as I called a solidity function and that emit ...
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1answer
92 views

getAccounts in web3 js undefined

I am working on dapp with web3js 1.0.0.37-beta with reactjs. I got blank in web3.eth.getAccounts. Following is my code App.js import React, {Component} from 'react'; import '../node_modules/...
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0answers
28 views

How to use the ipfs.add() function?

Here is a function that I have written to add a file on clicking a button, which calls the function 'onSubmit' onSubmit = async (event) => { event.preventDefault() await ipfs.add(this.state....
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1answer
1k views

Metamask transaction confirmed but “Internal JSON RPC error”

I am using getWeb3() to instantiate a contract and make calls with, the transaction says that is confirmed but when I open up developer tools there is the following error MetaMask - RPC Error: ...
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2answers
1k views

This contract object doesn't have address set yet, please set an address first

I am in the final stages of developing an application that is similar to https://www.ethereum.org/crowdsale, however, when I click on the create button, my Metamask modal is not popping up to ask me ...
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0answers
33 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(...
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0answers
13 views

Getting error when importing, no error when using code in single file: Failed to execute 'postMessage' on 'Window'

I am trying to access the web3 object injected into my browser by Metamask. I am using custom rpc (). I can see my accounts and correct balances in Metamask. I have the following code: //web3.js ...
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0answers
40 views

uncaught error:invalid address

Uncaught (in promise) Error: invalid address at inputAddressFormatter (formatters.js:271) at inputTransactionFormatter (formatters.js:97) at method.js:89 at Array.map (<anonymous>...