file.jsx

class SecondarySelections extends React.Component {
  constructor(props) {
    super(props);
    this.state = {
      message: null
    };
  }   
  updateMessage() {
    if (this.props.auxiliaryVerbs['passiveVoiceRequestedAndUnavailable'] == true) {
      this.setState({
        message: "Passive voice is not available in this verb tense"
      });      
    } else if ((this.props.subjectiveOrAuxiliarySelected == true) && (this.props.objectiveSelected == false)) {
      this.setState({
        message: "Subjective or auxiliary is selected"
      });       
    } else if ((this.props.objectiveSelected == true) && (this.props.objectiveSelected == false))  {
      this.setState({
        message: "Objective is selected"
      });       
    } else if ((this.props.subjectiveOrAuxiliarySelected == false) && (this.props.objectiveSelected == false))  {
      this.setState({
        message: "Neither is selected"
      });       
    }
  }  
  render() { 
    return (
      <div>
        {this.props.voiceSelected != null &&      
          <div> 
            {this.state.message}
          </div>
        }
      </div>
    );
  }
};