mastodon/app/assets/javascripts/components/features/following/index.jsx

import { connect } from 'react-redux';
import PureRenderMixin from 'react-addons-pure-render-mixin';
import ImmutablePropTypes from 'react-immutable-proptypes';
import LoadingIndicator from '../../components/loading_indicator';
import {
  fetchFollowing,
  expandFollowing
} from '../../actions/accounts';
import { ScrollContainer } from 'react-router-scroll';
import AccountContainer from '../../containers/account_container';

const mapStateToProps = (state, props) => ({
  accountIds: state.getIn(['user_lists', 'following', Number(props.params.accountId), 'items'])
});

const Following = React.createClass({

  propTypes: {
    params: React.PropTypes.object.isRequired,
    dispatch: React.PropTypes.func.isRequired,
    accountIds: ImmutablePropTypes.list
  },

  mixins: [PureRenderMixin],

  componentWillMount () {
    this.props.dispatch(fetchFollowing(Number(this.props.params.accountId)));
  },

  componentWillReceiveProps(nextProps) {
    if (nextProps.params.accountId !== this.props.params.accountId && nextProps.params.accountId) {
      this.props.dispatch(fetchFollowing(Number(nextProps.params.accountId)));
    }
  },

  handleScroll (e) {
    const { scrollTop, scrollHeight, clientHeight } = e.target;

    if (scrollTop === scrollHeight - clientHeight) {
      this.props.dispatch(expandFollowing(Number(this.props.params.accountId)));
    }
  },

  render () {
    const { accountIds } = this.props;

    if (!accountIds) {
      return <LoadingIndicator />;
    }

    return (
      <ScrollContainer scrollKey='following'>
        <div className='scrollable' onScroll={this.handleScroll}>
          <div>
            {accountIds.map(id => <AccountContainer key={id} id={id} withNote={false} />)}
          </div>
        </div>
      </ScrollContainer>
    );
  }

});

export default connect(mapStateToProps)(Following);