new_change_handler.js

changeHandler = event => {
    
    const name = event.target.name;
    const value = event.target.value;
    
    const updatedControls = {
	...this.state.formControls
    };
    const updatedFormElement = {
	...updatedControls[name]
    };
    updatedFormElement.value = value;
    updatedFormElement.touched = true;
    updatedFormElement.valid = validate(value, updatedFormElement.validationRules);

    updatedControls[name] = updatedFormElement;

    this.setState({
    	formControls: updatedControls
    });
	
}