options¶

An Web3 module does provide several options for configuring the transaction confirmation worklfow or for defining default values. These are the currently available option properties on a Web3 module:

Module Options¶

defaultAccount

defaultBlock

defaultGas

defaultGasPrice

transactionBlockTimeout

transactionConfirmationBlocks

transactionPollingTimeout

transactionSigner

Example¶

import Web3 from 'web3';

const options = {
    defaultAccount: '0x0',
    defaultBlock: 'latest',
    defaultGas: 1,
    defaultGasPrice: 0,
    transactionBlockTimeout: 50,
    transactionConfirmationBlocks: 24,
    transactionPollingTimeout: 480,
    transactionSigner: new CustomTransactionSigner()
}

const web3 = new Web3('http://localhost:8545', null, options);

defaultBlock¶

web3.defaultBlock
web3.eth.defaultBlock
web3.shh.defaultBlock
...

The default block is used for all methods which have a block parameter. You can override it by passing the block parameter if a block is required.

Example:

Returns¶

The defaultBlock property can return the following values:

Number: A block number
"genesis" - String: The genesis block
"latest" - String: The latest block (current head of the blockchain)
"pending" - String: The currently mined block (including pending transactions)

Default is "latest"

defaultAccount¶

web3.defaultAccount
web3.eth.defaultAccount
web3.shh.defaultAccount
...

This default address is used as the default "from" property, if no "from" property is specified.

Returns¶

String - 20 Bytes: Any Ethereum address. You need to have the private key for that address in your node or keystore. (Default is undefined)

defaultGasPrice¶

web3.defaultGasPrice
web3.eth.defaultGasPrice
web3.shh.defaultGasPrice
...

The default gas price which will be used for a request.

Returns¶

string|number: The current value of the defaultGasPrice property.

defaultGas¶

web3.defaultGas
web3.eth.defaultGas
web3.shh.defaultGas
...

The default gas which will be used for a request.

Returns¶

string|number: The current value of the defaultGas property.

transactionBlockTimeout¶

web3.transactionBlockTimeout
web3.eth.transactionBlockTimeout
web3.shh.transactionBlockTimeout
...

The transactionBlockTimeout will be used over a socket based connection. This option does define the amount of new blocks it should wait until the first confirmation happens. This means the PromiEvent rejects with a timeout error when the timeout got exceeded.

Returns¶

number: The current value of transactionBlockTimeout

transactionConfirmationBlocks¶

web3.transactionConfirmationBlocks
web3.eth.transactionConfirmationBlocks
web3.shh.transactionConfirmationBlocks
...

This defines the number of blocks it requires until a transaction will be handled as confirmed.

Returns¶

number: The current value of transactionConfirmationBlocks

transactionPollingTimeout¶

web3.transactionPollingTimeout
web3.eth.transactionPollingTimeout
web3.shh.transactionPollingTimeout
...

The transactionPollingTimeout will be used over a HTTP connection. This option does define the amount of polls (each second) it should wait until the first confirmation happens.

Returns¶

number: The current value of transactionPollingTimeout

transactionSigner¶

web3.eth.transactionSigner
...

The transactionSigner property does provide us the possibility to customize the signing process of the Eth module and the related sub-modules.

The interface of a TransactionSigner:

interface TransactionSigner {
    sign(txObject: Transaction): Promise<SignedTransaction>
}

interface SignedTransaction {
    messageHash: string,
    v: string,
    r: string,
    s: string,
    rawTransaction: string
}

Returns¶

TransactionSigner: A JavaScript class of type TransactionSigner.

setProvider¶

web3.setProvider(myProvider)
web3.eth.setProvider(myProvider)
web3.shh.setProvider(myProvider)
web3.bzz.setProvider(myProvider)
...

Will change the provider for its module.

Note

When called on the umbrella package web3 it will also set the provider for all sub modules web3.eth, web3.shh, etc EXCEPT web3.bzz which needs a separate provider at all times.

Parameters¶

Object|String - provider: a valid provider
Net - net: (optional) the node.js Net package. This is only required for the IPC provider.

Returns¶

Boolean

Example¶

import Web3 from 'web3';

const web3 = new Web3('http://localhost:8545');

// or
const web3 = new Web3(new Web3.providers.HttpProvider('http://localhost:8545'));

// change provider
web3.setProvider('ws://localhost:8546');
// or
web3.setProvider(new Web3.providers.WebsocketProvider('ws://localhost:8546'));

// Using the IPC provider in node.js
const net = require('net');
const web3 = new Web3('/Users/myuser/Library/Ethereum/geth.ipc', net); // mac os path

// or
const web3 = new Web3(new Web3.providers.IpcProvider('/Users/myuser/Library/Ethereum/geth.ipc', net)); // mac os path
// on windows the path is: '\\\\.\\pipe\\geth.ipc'
// on linux the path is: '/users/myuser/.ethereum/geth.ipc'

providers¶

Web3.providers
Eth.providers
...

Contains the current available providers.

Value¶

Object with the following providers:

Object - HttpProvider: The HTTP provider is deprecated, as it won’t work for subscriptions.

Object - WebsocketProvider: The Websocket provider is the standard for usage in legacy browsers.

Object - IpcProvider: The IPC provider is used node.js dapps when running a local node. Gives the most secure connection.

Example¶

const Web3 = require('web3');
// use the given Provider, e.g in Mist, or instantiate a new websocket provider
const web3 = new Web3(Web3.givenProvider || 'ws://localhost:8546');
// or
const web3 = new Web3(Web3.givenProvider || new Web3.providers.WebsocketProvider('ws://localhost:8546'));

// Using the IPC provider in node.js
const net = require('net');

const web3 = new Web3('/Users/myuser/Library/Ethereum/geth.ipc', net); // mac os path
// or
const web3 = new Web3(new Web3.providers.IpcProvider('/Users/myuser/Library/Ethereum/geth.ipc', net)); // mac os path
// on windows the path is: '\\\\.\\pipe\\geth.ipc'
// on linux the path is: '/users/myuser/.ethereum/geth.ipc'

givenProvider¶

Web3.givenProvider
web3.eth.givenProvider
web3.shh.givenProvider
web3.bzz.givenProvider
...

When using web3.js in an Ethereum compatible browser, it will set with the current native provider by that browser. Will return the given provider by the (browser) environment, otherwise null.

Returns¶

Object: The given provider set or false.

Example¶

web3.setProvider(Web3.givenProvider || 'ws://localhost:8546');

currentProvider¶

web3.currentProvider
web3.eth.currentProvider
web3.shh.currentProvider
web3.bzz.currentProvider
...

Will return the current provider.

Returns¶

Object: The current provider set.

Example¶

if (!web3.currentProvider) {
    web3.setProvider('http://localhost:8545');
}

BatchRequest¶

new web3.BatchRequest()
new web3.eth.BatchRequest()
new web3.shh.BatchRequest()
...

Class to create and execute batch requests.

Parameters¶

none

Returns¶

Object: With the following methods:

add(request): To add a request object to the batch call.

execute(): Will execute the batch request.

Example¶

const contract = new web3.eth.Contract(abi, address);

const batch = new web3.BatchRequest();
batch.add(web3.eth.getBalance.request('0x0000000000000000000000000000000000000000', 'latest'));
batch.add(contract.methods.balance(address).call.request({from: '0x0000000000000000000000000000000000000000'}));
batch.execute().then(...);