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¶
Example¶
import Web3 from 'web3';
const options = {
defaultAccount: '0x0',
defaultBlock: 'latest',
defaultGas: 1,
defaultGasPrice: 0,
transactionBlockTimeout: 50,
transactionConfirmationBlocks: 24,
transactionPollingTimeout: 480
}
const web3 = new Web3('http://localhost:8545', options);
defaultBlock¶
web3.defaultBlock
web3.eth.defaultBlock
web3.shh.defaultBlock
...
The default block which will be used for a requests.
defaultAccount¶
web3.defaultAccount
web3.eth.defaultAccount
web3.shh.defaultAccount
...
The default account which will be used for a requests.
defaultGasPrice¶
web3.defaultGasPrice
web3.eth.defaultGasPrice
web3.shh.defaultGasPrice
...
The default gas price which will be used for a request.
defaultGas¶
web3.defaultGas
web3.eth.defaultGas
web3.shh.defaultGas
...
The default gas which will be used for a request.
transactionBlockTimeout¶
web3.transactionBlockTimeout
web3.eth.transactionBlockTimeout
web3.shh.transactionBlockTimeout
...
This can be used with a socket provider and defines the number of blocks until the PromiEvent rejects with a timeout error.
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. The PromiEvent will resolve with the desired receipt when enough confirmations happened.
transactionPollingTimeout¶
web3.transactionPollingTimeout
web3.eth.transactionPollingTimeout
web3.shh.transactionPollingTimeout
...
This defines the polling cycles amount when you send a transaction with the HttpProvider. The PromiEvent rejects with a timeout error when the timeout got exceeded. (1 cycle == 1sec.).
Returns¶
number: The current value of transactionPollingTimeout
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 providerNet-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 null;
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, otherwise null.
Returns¶
Object: The current provider set or null;
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', callback));
batch.add(contract.methods.balance(address).call.request({from: '0x0000000000000000000000000000000000000000'}, callback2));
batch.execute();