React - Thunk inputs

thunk_inputs.js

  inputOnChange = propName => ev => this.setState({ [propName] : ev.target.value })
  
  render () {
    return (
      <form onSubmit={this.handleLogin} >
        <input
          type='input'
          value={this.state.user}
          placeholder='username'
          className='header-login-input'
          name='username'
          onChange={this.inputOnChange('user')} />
        <input
          type='input'
          value={this.state.password}
          placeholder='password'
          className='header-login-input'
          name='password'
          onChange={this.inputOnChange('password')} />
        <input
          type='submit'
          value='Login Now' />
      </form>
    )
  }