ens-usernames/app/components/erc20token.js

import lang from 'i18n-js';
import EmbarkJS from 'Embark/EmbarkJS';
import ERC20Token from 'Embark/contracts/ERC20Token';
import React from 'react';
import { connect } from 'react-redux';
import { Form, FormGroup, FormControl, HelpBlock, Button } from 'react-bootstrap';
import { getCurrentAccount, accountsIsLoading } from '../reducers/accounts';

class ERC20TokenUI extends React.Component {
  constructor(props) {
    super(props);
    ERC20Token.options.address = props.address;
    this.state = {
      balanceOf: 0,
      transferTo: '',
      transferAmount: 0,
      accountB: web3.eth.defaultAccount,
    };
  }

  update_transferTo(e) {
    this.setState({ transferTo: e.target.value });
  }

  update_transferAmount(e) {
    this.setState({ transferAmount: e.target.value });
  }

  transfer(e){
    var to = this.state.transferTo;
    var amount = this.state.transferAmount;
    var tx = ERC20Token.methods.transfer(to, amount).send({from: web3.eth.defaultAccount});
    this._addToLog(ERC20Token.options.address+".transfer(" + to + ", "+amount+")");
  }

  approve(e){
    var to = this.state.transferTo;
    var amount = this.state.transferAmount;
    var tx = ERC20Token.methods.approve(to, amount).send({from: web3.eth.defaultAccount});
    this._addToLog(ERC20Token.options.address+".approve(" + to + ", "+amount+")");
  }

  balanceOf(e){
    e.preventDefault();
    var who = e.target.value;
    if (EmbarkJS.isNewWeb3()) {
      ERC20Token.methods.balanceOf(who).call()
        .then(_value => this.setState({balanceOf: _value}))
    } else {
      ERC20Token.balanceOf(who)
        .then(_value => this.x({balanceOf: _value}));
    }
    this._addToLog(ERC20Token.options.address+".balanceOf(" + who + ")");
  }

  getDefaultAccountBalance(){
    if (EmbarkJS.isNewWeb3()) {
      ERC20Token.methods.balanceOf(web3.eth.defaultAccount).call()
        .then(_value => this.setState({accountBalance: _value}))
    } else {
      ERC20Token.balanceOf(web3.eth.defaultAccount)
        .then(_value => this.x({valueGet: _value}))
    }
    this._addToLog(ERC20Token.options.address + ".balanceOf(" + web3.eth.defaultAccount + ")");
  }

  _addToLog(txt){
    console.log(txt);
  }

  render() {
    const { account, isLoading } = this.props;
    return (
      <React.Fragment>
        <h3>{lang.t('account.read_your_token_balance')}</h3>
        <Form inline>
          <FormGroup>
            {!isLoading && <HelpBlock>{lang.t('account.your_test_token_balance')} <span className="accountBalance">{account.SNTBalance}</span></HelpBlock>}
          </FormGroup>
        </Form>

        <h3>{lang.t('account.read_token_balance')}</h3>
        <Form inline>
          <FormGroup>
            <label>
              {lang.t('account.of')}{':'}
              <FormControl
                type="text"
                defaultValue={this.state.accountB}
                onChange={e => this.balanceOf(e)}
              />
            </label>
            <label>
              <HelpBlock><span className="balanceOf">{this.state.balanceOf}</span></HelpBlock>
            </label>
          </FormGroup>
        </Form>

        <h3>{lang.t('account.transfer_approve_token_balance')}</h3>
        <Form inline>
          <FormGroup>
            <label>
              {lang.t('account.to')}{':'}
              <FormControl
                type="text"
                defaultValue={this.state.transferTo}
                onChange={e => this.update_transferTo(e)}
              />
            </label>
            <label>
              {lang.t('account.amount')}{':'}
              <FormControl
                type="text"
                defaultValue={this.state.transferAmount}
                onChange={e => this.update_transferAmount(e)}
              />
            </label>
            <Button bsStyle="primary" onClick={e => this.transfer(e)}>{lang.t('action.transfer')}</Button>
            <Button bsStyle="primary" onClick={e => this.approve(e)}>{lang.t('action.approve')}</Button>
          </FormGroup>
        </Form>
      </React.Fragment>
    );
  }
}

const mapStateToProps = state => ({
  account: getCurrentAccount(state),
  isLoading: accountsIsLoading(state),
});

export default connect(mapStateToProps)(ERC20TokenUI);