gistfile1.txt

var Parent = React.createClass({

  onInputChange(e) {
    this.setState({
      input: e.target.value
    });
  },
  
  filterCities(cities, input) {
    return cities.filter(city => {
      // ...
    });
  },
  
  render() {
    return (
      <div>
        <SearchFilter
          onInputChange={ this.onInputChange } />
        <CityList
          cities={ this.filterCities(this.state.cities, this.state.input) }>
    );
  }
});