Материал пользовательского интерфейса ошибка
Using a react component state, one can store the TextField value and use that as an indicator for an error. Material-UI exposes the error and helperText props to display an error interactively.
Take a look at the following example:
<TextField
value={this.state.text}
onChange={event => this.setState({ text: event.target.value })}
error={text === ""}
helperText={text === "" ? 'Empty field!' : ' '}
/>
Santino