content: import React from 'react';
  import { connect } from 'react-redux';
  import PropTypes from 'prop-types';
  import StatusListContainer from '../ui/containers/status_list_container';
  import Column from '../../components/column';
  import ColumnHeader from '../../components/column_header';
  import { expandHashtagTimeline } from '../../actions/timelines';
  import { addColumn, removeColumn, moveColumn } from '../../actions/columns';
  import { FormattedMessage } from 'react-intl';
  import { connectHashtagStream } from '../../actions/streaming';
  
  const mapStateToProps = (state, props) => ({
    hasUnread: state.getIn(['timelines', `hashtag:${props.params.id}`, 'unread']) > 0,
  });
  
  export default @connect(mapStateToProps)
  class HashtagTimeline extends React.PureComponent {
  
    static propTypes = {
      params: PropTypes.object.isRequired,
      columnId: PropTypes.string,
      dispatch: PropTypes.func.isRequired,
      shouldUpdateScroll: PropTypes.func,
      hasUnread: PropTypes.bool,
      multiColumn: PropTypes.bool,
    };
  
    handlePin = () => {
      const { columnId, dispatch } = this.props;
  
      if (columnId) {
        dispatch(removeColumn(columnId));
      } else {
        dispatch(addColumn('HASHTAG', { id: this.props.params.id }));
      }
    }
  
    handleMove = (dir) => {
      const { columnId, dispatch } = this.props;
      dispatch(moveColumn(columnId, dir));
    }
  
    handleHeaderClick = () => {
      this.column.scrollTop();
    }
  
    _subscribe (dispatch, id) {
      this.disconnect = dispatch(connectHashtagStream(id));
    }
  
    _unsubscribe () {
      if (this.disconnect) {
        this.disconnect();
        this.disconnect = null;
      }
    }
  
    componentDidMount () {
      const { dispatch } = this.props;
      const { id } = this.props.params;
  
      dispatch(expandHashtagTimeline(id));
      this._subscribe(dispatch, id);
    }
  
    componentWillReceiveProps (nextProps) {
      if (nextProps.params.id !== this.props.params.id) {
        this.props.dispatch(expandHashtagTimeline(nextProps.params.id));
        this._unsubscribe();
        this._subscribe(this.props.dispatch, nextProps.params.id);
      }
    }
  
    componentWillUnmount () {
      this._unsubscribe();
    }
  
    setRef = c => {
      this.column = c;
    }
  
    handleLoadMore = maxId => {
      this.props.dispatch(expandHashtagTimeline(this.props.params.id, { maxId }));
    }
  
    render () {
      const { shouldUpdateScroll, hasUnread, columnId, multiColumn } = this.props;
      const { id } = this.props.params;
      const pinned = !!columnId;
  
      return (
        <Column ref={this.setRef} label={`#${id}`}>
          <ColumnHeader
            icon='hashtag'
            active={hasUnread}
            title={id}
            onPin={this.handlePin}
            onMove={this.handleMove}
            onClick={this.handleHeaderClick}
            pinned={pinned}
            multiColumn={multiColumn}
            showBackButton
          />
  
          <StatusListContainer
            trackScroll={!pinned}
            scrollKey={`hashtag_timeline-${columnId}`}
            timelineId={`hashtag:${id}`}
            onLoadMore={this.handleLoadMore}
            emptyMessage={<FormattedMessage id='empty_column.hashtag' defaultMessage='There is nothing in this hashtag yet.' />}
            shouldUpdateScroll={shouldUpdateScroll}
          />
        </Column>
      );
    }
  
  }
  