navbar not rendering in browser using ng-bootstrap & angular 4

Question

I am building my first Angular 4 app, using ng-bootstrap (Bootstrap 4 for Angular) - not using regular Boostrap

The ng-bootstrap website (https://ng-bootstrap.github.io/#/components/accordion/api) does not list a component for a navbar (as it did in Bootstrap 3 or regular bootstrap 4). Does that mean I have to build a menu out of dropdowns/buttons? Or I have to mix regular Bootstrap 4 with ng-bootstrap?

I tried creating this menu in the html but it won't render in the browser (just a brand "MyWebSiteName" and little grey box on my screen, no nav)

<nav class="navbar navbar-inverse">
  <div class="container-fluid">
    <div class="navbar-header">
      <button type="button" class="navbar-toggle" data-toggle="collapse" data-target="#myNavbar">
        <span class="icon-bar"></span>
        <span class="icon-bar"></span>
        <span class="icon-bar"></span>
      </button>
      <a class="navbar-brand" href="#">MyWebSiteName</a>
    </div>
     <div class="collapse navbar-collapse" id="myNavbar">
      <ul class="nav navbar-nav">
        <li class="active"><a href="#">Home</a></li>
        <li class="dropdown">
          <a class="dropdown-toggle" data-toggle="dropdown" href="#">Page 1 <span class="caret"></span></a>
          <ul class="dropdown-menu">
            <li><a href="#">Page 1-1</a></li>
            <li><a href="#">Page 1-2</a></li>
            <li><a href="#">Page 1-3</a></li>
          </ul>
        </li>
        <li><a href="#">Page 2</a></li>
        <li><a href="#">Page 3</a></li>
      </ul>
      <ul class="nav navbar-nav navbar-right">
        <li><a href="#"><span class="glyphicon glyphicon-user"></span> Sign Up</a></li>
        <li><a href="#"><span class="glyphicon glyphicon-log-in"></span> Login</a></li>
      </ul>
    </div>
  </div>
</nav>

I something wrong with this HTML ? Or does someone have an example of a Navbar that works with ng-bootstrap?

Answer 1

As there is no navigation component you'd need to use a combination of the collapse functionality ng-bootstrap's ngbCollapse component as well as the dropdown functionality from the NgbDropdown component.

You'll need to bind an instance of ngbCollapse to the div.collapse.navbar-collapse and a boolean property on your component class. ng-bootstrap doesn't have any use for data-* so you can remove attributes such as data-toggle="collapse".

You control the open/close state of the collapse menu via a property on your component class that gets toggled true/false through something like a click event. In this example is toggle via a (click) event handler on the button.navbag-toggler executing a method on the component toggleMenu() which simply inverts the value of boolean property isCollapsed via the ! operator.

For the menu item dropdown menu, you'd use the NgbDropdown component. You'd apply attributes ngbDropdown and ngbDropdownToggle to the container element and toggle element respectively.

<div class="nav-item dropdown" ngbDropdown>
  <a class="nav-link dropdown-toggle" id="navbarDropdownMenuLink" ngbDropdownToggle>
    Dropdown
  </a>
  <div class="dropdown-menu" aria-labelledby="dropdownBasic1">
    <button class="dropdown-item">Action - 1</button>
    <button class="dropdown-item">Another Action</button>
    <button class="dropdown-item">Something else is here</button>
  </div>
</div>

In terms of styling for Bootstrap 4 navbar, you'll need to use the following classes:

Navbars require a wrapping .navbar with .navbar-toggleable-* for responsive collapsing and color scheme classes.

Also elements such as button.navbar-toggle are now button.navbar-toggler with an "r" in Bootstrap 4. You use classes navbar-inverse and bg-inverse for the standard inverse navbar.

HTML:

<nav class="navbar navbar-toggleable-md navbar-inverse bg-inverse">
  <button class="navbar-toggler navbar-toggler-right" type="button" aria-controls="appNavigation" [attr.aria-expanded]="!isCollapsed" aria-label="Toggle navigation" (click)="toggleMenu()">
    <span class="navbar-toggler-icon"></span>
  </button>
  <a class="navbar-brand" href="#">My App</a>
  <div class="collapse navbar-collapse" id="appNavigation" [ngbCollapse]="isCollapsed">
    <div class="navbar-nav mr-auto">
      <a class="nav-item nav-link" routerLink="" routerLinkActive="active">Home</a>
      <a class="nav-item nav-link" routerLink="/about" routerLinkActive="active">About</a>
      <div class="nav-item dropdown" ngbDropdown>
        <a class="nav-link dropdown-toggle" id="navbarDropdownMenuLink" ngbDropdownToggle>
            Dropdown
        </a>
        <div class="dropdown-menu" aria-labelledby="dropdownBasic1">
          <button class="dropdown-item">Action - 1</button>
          <button class="dropdown-item">Another Action</button>
          <button class="dropdown-item">Something else is here</button>
        </div>
      </div>
    </div>
  </div>
</nav>

TS:

export class NavigationComponent {
  isCollapsed = true;

  constructor() {}

  toggleMenu() {
    this.isCollapsed = !this.isCollapsed;
  }
}

Here is a plunker demonstrating the functionality and styling in action.

Answer 2

Instead of Using ng-Bootstrap try using Angular for the same.

Small Example

Template

<nav class="navbar navbar-toggleable-md navbar-light bg-faded  navbar-fixed-top">
  <button class="navbar-toggler navbar-toggler-right" type="button" data-toggle="collapse" data-target="#navbarNavDropdown"
    aria-controls="navbarNavDropdown" aria-expanded="false" aria-label="Toggle navigation" (click)="isActive = !isActive"> // add this for the responsive button
    <span class="navbar-toggler-icon"></span>
  </button>
  <a routerLink="/home"><img src="angular.png" class = "myImage" alt="Image"/></a>
  <div class="collapse navbar-collapse" id="navbarNavDropdown" [ngClass]="{show : isActive}">
    <ul class="navbar-nav">
      <li class="nav-item dropdown" [routerLinkActive]="['active']" appDropdown> // add this directive for the dropdown
        <a class="nav-link dropdown-toggle" id="navbarDropdownMenuLink" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
          Basic Concepts
        </a>
.....

Directive

 import {Directive, HostListener, HostBinding} from '@angular/core';

  @Directive({
    selector: '[appDropdown]'
  })
  export class DropdownDirective {

    private isOpen:boolean = false;

    @HostBinding('class.open') get opened(){
      return this.isOpen;
    }
    constructor() { }

    @HostListener('click')open(){
      this.isOpen = true;
    }

    @HostListener('mouseleave')close(){
      this.isOpen = false;
    }

Working example of the Same the navbar on top is made using bootstrap and Angular directives Link