React form, to submit object which is then pushed to array

Question

I'm new to React and unsure about how to do this.

I have an array of objects that I have mapped through and rendered in my view. What I want to do is set up a form that will submit the values of each field to the corresponding properties of a new object, but I'm not sure how to go about doing this.

Here is my initial data, which is rendered in the view:

contactArray = [
  {
    name: 'John'
    email: '[email protected]'
    number: 111-111-111
  },
  {
    name: 'Dave'
    email: '[email protected]'
    phone: '222-222-222'
  }
]

Then I have a form:

class InputForm extends Component {
  render() {
    return (   
        <form>
          <input type='text' onChange={this.handleChange}/>
          <input type='text' onChange={this.handleChange}/>
          <input type='text' onChange={this.handleChange}/>
          <button type='submit' onSubmit={this.handleSubmit}>SUBMIT</button>
        </form>
    ) 
  }

Then I assume I declare the state as this:

constructor(props) {
  super(props);
  this.state = {
    name: '',
    email: '',
    phone: ''
  }
}

Then the submission function I don't really know how to handle...

handleSubmit() {
  // not sure about this...
  this.setState({
    name: // ????
    email: // ????
    phone: // ????
  })
}

And then I want to clear the submit form, as well as the object that is used to push the new object, which is now in the array (I hope that makes sense...)

So, I'm not even sure how to use state in this scenario, but ultimately I want to push() the new object to the array that is rendered, with all the properties as they were completed in the form.

Sorry I can't be more complete with my working up to this point, but would at least appreciate some pointers on this!

Answer 1

From what I understand you want to push new people to the existing contactArray ? I will share with my way of doing it. Have a look:

const contactArray = [
{
    name: 'John',
    email: '[email protected]',
    phone: '111-111-111'
  },
  {
    name: 'Dave',
    email: '[email protected]',
    phone: '222-222-222'
  }
];

class Form extends React.Component {

  constructor() {
    super();
    this.state = {
      contacts: contactArray
    };
    this.handleSubmit = this.handleSubmit.bind(this);
  }

  handleSubmit(e) {
    e.preventDefault();
    const
    { contacts } = this.state,
    name = this.refs.name.value,
    email = this.refs.email.value,
    phone = this.refs.phone.value;
    this.setState({
      contacts: [...contacts, {
        name,
        email,
        phone
      }]
    }, () => {
      this.refs.name.value = '';
      this.refs.email.value = '';
      this.refs.phone.value = '';
    });
  }

  render() {
    const { contacts } = this.state;
    console.log('message',this.state.contacts);
    return (   
      <div>
        <h2>Add Someone</h2>
        <form onSubmit={this.handleSubmit}>
          <input type="text" ref="name" placeholder="name" />
          <input type="text" ref="email" placeholder="email" />
          <input type="text" ref="phone" placeholder="phone" />
          <button type="submit">Submit</button>
        </form>
        <h2>Exsiting contacts:</h2>
        <ul>
          {contacts.map((contact) => 
           <li>{`Name: ${contact.name} Email: ${contact.email} Phone: ${contact.phone}`}</li>
          )}
        </ul>
      </div>
    ) 
  }
}

ReactDOM.render(<Form />, document.getElementById('root'));

So first thing we do is save contactArray within our actual component where we are going to use it, next we decalre and bind our handleSubmit I am using refs for the inputs in order to get thier value. this.setState ({ contacts: [...contacts] , { Object }); Here we use the ES6 spread operator to pass all the existing contacts to our new state and add a new contact. { name, email, phone } Is exactly like doing { name:name, email:email ...} It's just a short-hand, this.setState({}, () => { Callback! }); In the callback function of this.setState({}); I am going to clear the input values. Live demo: http://codepen.io/ilanus/pen/qaXNmb

Here is another way you can do it, same results different approach.

const contactArray = [
  {
    name: 'John',
    email: '[email protected]',
    phone: '111-111-111'
  },
  {
    name: 'Dave',
    email: '[email protected]',
    phone: '222-222-222'
  }
];

class Form extends React.Component {

  constructor() {
    super();
    this.state = {
      contacts: contactArray,
      newContact: {
       name: '',
       email: '',
       phone: ''
     }
    };
    this.handleSubmit = this.handleSubmit.bind(this);
    this.handleInput = this.handleInput.bind(this);
  }

  handleSubmit(e) {
    e.preventDefault();
    const { contacts, newContact } = this.state;
    this.setState({
      contacts: [...contacts, newContact],
    }, () => {
      for (let val in newContact) {
        newContact[val] = ''; // Clear the values...
      }
      this.setState({ newContact });
    });
  }

  handleInput(e, element) {
    const { newContact } = this.state;
    newContact[element] = e.target.value;
    this.setState({ newContact });
  }

  render() {
    const { contacts, newContact } = this.state;
    const { name, email, phone } = newContact;
    return (   
      <div>
        <h2>Add Someone</h2>
        <form onSubmit={this.handleSubmit}>
          <input type="text" value={name} onChange={e => this.handleInput(e, 'name')} placeholder="name" />
          <input type="text" value={email} onChange={e => this.handleInput(e, 'email')} placeholder="email" />
          <input type="text" value={phone} onChange={e => this.handleInput(e, 'phone')} placeholder="phone" />
          <button type="submit">Submit</button>
        </form>
        <h2>Exsiting contacts:</h2>
        <ul>
          {contacts.map((contact) => 
           <li>{`Name: ${contact.name} Email: ${contact.email} Phone: ${contact.phone}`}</li>
          )}
        </ul>
      </div>
    ) 
  }
}

ReactDOM.render(<Form />, document.getElementById('root'));

Live demo: http://codepen.io/ilanus/pen/LRjkgx

I highly recommend using the first example. as it's performance will be better :)