A basic form with React

Question

I have been working of a basic from using React and I need your help to improve this part of my code, especially validate and onSubmit.

state = {
 email: "",
 emailError: "",
 }; 
 change = e => {
 this.setState({
 [e.target.name]: e.target.value
 });
 };
 validate = () => {
 let isError = false;
 const errors = {
 emailError: "",
 };
 if (this.state.email.indexOf("@") === -1) {
 isError = true;
 errors.emailError = "Requires valid email";
 }
 this.setState({
 ...this.state,
 ...errors
 });
 return isError;
 }; 
 onSubmit = e => {
 e.preventDefault();
 const err = this.validate();
 if (!err) {
 this.props.onSubmit(this.state);
 this.setState({
 email: "",
 emailError: "",
 });
 }
 };
 render() {
 return (
 <form>
 <TextField
 name="email"
 hintText="Email"
 floatingLabelText="Email"
 value={this.state.email}
 onChange={e => this.change(e)}
 errorText={this.state.emailError}
 floatingLabelFixed
 />
 <br />
 <RaisedButton label="Submit" onClick={e => this.onSubmit(e)} primary />
 </form>
 );

Answer 1

As far as I'm aware, CodeReview is for completed programs. I imagine that this question would be better suited in StackOverflow. That being said, I see no point in duping the question on a different site.

Without seeing the rest of the program, and solely in a time interest, I'd say you keep the change function and ignore the validations. If you want a form field to be required, you can add 'required' to the input.

<form>
 <input type="text" name="input1" value={this.state.input1} onChange={e => this.change(e)} required />
</form>

You can find more on the MDN web docs for the required attribute.

Side note: you can also bind this.change as this.change = this.change.bind(this) in the constructor if you intend on using it for multiple fields. It'll save you some bytes, but if it's just a one off, binding it in the element itself like you have should be fine.