React-Bootstrap Import NavBar module

Question

I am trying to recreate some code from the React-Bootstrap documentation in my Reat project (bootstrapped with create-react-app).

But I have a problem with these Boostrap "sub-components" like NavBar.Header

This my code:

import React, {Component} from 'react';
import {NavBar, Nav, NavItem} from 'react-bootstrap';

class MainNav extends Component {
  render() {
    return (
      <Navbar>
        <Navbar.Header>
          <Navbar.Brand>
            <a href="#">React-Bootstrap</a>
          </Navbar.Brand>
        </Navbar.Header>
        <Nav>
          <NavItem eventKey={1} href="#">Link</NavItem>
          <NavItem eventKey={2} href="#">Link</NavItem>
          <NavDropdown eventKey={3} title="Dropdown" id="basic-nav-    dropdown">
            <MenuItem eventKey={3.1}>Action</MenuItem>
            <MenuItem eventKey={3.2}>Another action</MenuItem>
            <MenuItem eventKey={3.3}>Something else here</MenuItem>
            <MenuItem divider />
            <MenuItem eventKey={3.4}>Separated link</MenuItem>
          </NavDropdown>
        </Nav>
      </Navbar>
    )
  }
}

export default MainNav;

I get the following console error:

Uncaught TypeError: Cannot read property 'Header' of undefined
    at MainNav.render (MainNav.js:15)
    at ReactCompositeComponent.js:796
    at measureLifeCyclePerf (ReactCompositeComponent.js:75)
    at     ReactCompositeComponentWrapper._renderValidatedComponentWithoutOwnerOrContext     (ReactCompositeComponent.js:795)
    at ReactCompositeComponentWrapper._renderValidatedComponent     (ReactCompositeComponent.js:822)
    at ReactCompositeComponentWrapper.performInitialMount (ReactCompositeComponent.js:362)
    at ReactCompositeComponentWrapper.mountComponent     (ReactCompositeComponent.js:258)
    at Object.mountComponent (ReactReconciler.js:46)
    at ReactDOMComponent.mountChildren (ReactMultiChild.js:238)
    at ReactDOMComponent._createInitialChildren (ReactDOMComponent.js:697)

I found this article, which seems to explain the issue: http://www.ericfeminella.com/blog/2016/08/12/react-bootstrap-es6-imports/

But the solution does not work for me. When I try to import directly from the /lib/NavBar directory, I get a compile error:

Error in ./src/container/blocks/MainNav.js
Module not found: 'react-bootstrap/lib/NavBar' in /homefolder/project/src/containers/blocks

Can anybody help me with his?

Answer 1

There are two main issues I can see in your code:

1. Typo: You are using Bootstrap's Navbar component but trying to import the component as NavBar; Notice the uppercase "B" in the import.
2. Imports: Every component that you intend to use needs to be imported. You are missing NavDropdown and MenuItem.

Your imports should look like the following:

import React, { Component } from 'react'; 
import { Navbar, Nav, NavItem, NavDropdown, MenuItem } from 'react-bootstrap';

Once that is corrected your component will run.