react-web3-components

A set components to create DApp interfaces using react.

The core component is Web3Provider which exposes a web3 instance along with account state to nested components in this library using a specific react context (Web3Context). Other components can be nested anywhere in the virtual dom.

Available components:

• Sign: sign a message with the selected account.
• Accounts: the list of available accounts.
• SelectedAccount: the currently selected account.
• NewAccount: create a new account.
• Unlock: unlock the selected account.

Use with Metamask

By default, the Web3Provider will use a web3 instance using the browser's givenProvider (which is in most cases Metamask).

<Web3Provider>
  <Sign message='hello'/>
</Web3Provider>

Use a custom instance of web3

It is possible to specify a custom instance of web3 to use, for example, with a WebSocket provider to connect to a local geth node.

let wsWeb3 = new Web3(new Web3.providers.WebsocketProvider('ws://localhost:8546'));

const app = () => {
  <Web3Provider web3={wsWeb3}>
    ...
  </Web3Provider>
}

Customize rendering

In general, component render can be customized using functions as child components. See below for properties available for each component.

Example – Login users using Metamask's signature:

<Web3Provider>
  <Sign
    message='Login nonce: 1234'
    onSign={console.log}
    onError={console.error}
  >
    {
      ({
        message,
        disabled,
        selectedAccount,
        signAction,
      }) => (
        <div>
          <button disabled={disabled} onClick={signAction}>
            Login with <code>{disabled ? '': `${selectedAccount.substring(0, 6)}…`}</code>
          </button>
        </div>
      )
    }
  </Sign>
</Web3Provider>

API

Web3Provider, Web3Context

Handles update events and Metamask account access requests. Initializes and manages the context provided to other components.

Params:

• web3: Specifies the web3 instance to use (default new Web3(Web3.givenProvider)).
• onUpdate: A callback triggered each time accounts state changes.
• logger: Possibly a custom logger handler.

Exposes a Web3Context provider which gives access to an object containing:

• web3: The instance of web3 used by this provider.
• selectedAccount: The selected account.
• accounts: An array of all available accounts.
• updateAccounts: A function to force update of the accounts state. This function receives a single optional parameter to specify the account that should be selected. If null the selected account will use the first available account.

Sign

Sign a message with the selected account.

Params:

• message: The message to be signed, this can be either a string or a Buffer (default '').

• password: The password (if needed). This is needed for accounts protected with password as in geth accounts when using a WebSocket provider. Metamask doesn't need a password.

• onSign: A callback for accessing the resulting signature (default () => {}). The signature result is an object of the form:

    {
      signature,  // The hex formatted signature as returned by web3
      signedBy,   // The account that signed the message
      message,    // The original message
      hexMessage, // The hex formatted message
    }

• onError: A callback for handling errors if any (default () => {}). This function receives a single parameter, the error message.

Child function:

The child function for custom rendering receives an object containing:

• message: The message to be signed.
• disabled: true if no account selected, false otherwise.
• selectedAccount: The account that will sign the message.
• signAction: The action that, when triggered, will request the signature.

SelectedAccount

Shows the currently selected account.

Params:

• none

Child function:

The child function for custom rendering receives an object containing:

• selectedAccount: The selected address.

Accounts

Shows the list of available accounts and allows to select an account when many available (such as when connecting to a geth instance with a WebSocket web3 provider).

Params:

• none

Child function:

The child function for custom rendering receives an object containing:

• selectedAccount: The selected address.
• accounts: An array of all available accounts.
• updateAccounts: A function to set the selected account and update the list of available accounts.

NewAccount

Creates a new account and if succeeds, sets it as the selected account (Doesn't work with Metamask).

Params:

• password: The password for the newly created account (default '')
• onCreate: A callback for accessing the newly created account (default () => {}). This function receives a single parameter, the new address.
• onError: A callback for handling errors if any (default () => {}). This function receives a single parameter, the error message.

Child function:

The child function for custom rendering receives an object containing:

• newAccountAction: The action that, when triggered, will create a new account.

Unlock

Unlock the selected account (Doesn't work with Metamask).

Params:

• password: The password for unlocking the account (default '').
• duration: The duration for unlocking the account (default 0).
• onUnlock: A callback called when the account was unlocked (default () => {}). This function receives a single parameter, true if the account was unlocked.
• onError: A callback for handling errors if any (default () => {}). This function receives a single parameter, the error message.

Child function:

The child function for custom rendering receives an object containing:

• selectedAccount: The selected address.
• duration: The duration for unlocking the account.
• unlockAction: The action that, when triggered, will request the account unlocking.
• disabled: true if no account selected, false otherwise.