ReactMap_onLoad.js

this.map.on('load', () => {
  // Get the map style and set it in the state tree
  const style = this.map.getStyle();
  this.props.setStyle(style); // <= action creator

  // Listen for a map click, get the features under the pointer
  // and pass them to a "clickMap" action that might update our UI
  // or highlight the feature in the stylesheet:
  this.map.on('click', event => {
    const features = this.map.queryRenderedFeatures(event.point);
    this.props.clickMap(features); // <= action creator
    
    // We can also use the native mapbox popup if the clickMap
    // action sets some html to show and passes it as a prop:
    if(this.props.popupMarkup) {
      new mapboxgl.Popup()
        .setLngLat(event.lngLat)
        .setHTML(this.props.popupMarkup)
        .addTo(this.map);
    }
  });
});