BeatsByTag.js

import React, { Component } from "react";
import { connect } from "react-redux";
import { getBeatsByTag } from "../../actions/beatActions";
import { Link } from "react-router-dom";
import PropTypes from "prop-types";

class BeatsByTag extends Component {
  constructor(props) {
    super(props);
    this.state = {
      beats: []
    };
  }

  componentDidMount() {
    if (this.props.match.params.tag) {
      this.props.getBeatsByTag(this.props.match.params.tag);
    }
  }

  render() {
    const { beats } = this.state;

    let content;

    content = beats.map(b => <Link to="/">{b.name}</Link>);

    return <div>{content ? content : null}</div>;
  }
}

BeatsByTag.propTypes = {
  getBeatsByTag: PropTypes.func.isRequired,
  beat: PropTypes.object.isRequired,
  error: PropTypes.object.isRequired
};
const mapStateToProps = state => ({
  beat: state.beat,
  error: state.error
});
export default connect(mapStateToProps, { getBeatsByTag })(BeatsByTag);