bootstrap-vue/src/components/navbar/README.md

With more than 85 components, over 45 available plugins, several directives, and 1000+ icons, BootstrapVue provides one of the most comprehensive implementations of the Bootstrap v4 component and grid system available for Vue.js v2.6, complete with extens

# Navbar

> The component `<b-navbar>` is a wrapper that positions branding, navigation, and other elements
> into a concise header. It's easily extensible and thanks to the `<b-collapse>` component, it can
> easily integrate responsive behaviors.

**Example:**

```html
<div>
  <b-navbar toggleable="lg" type="dark" variant="info">
    <b-navbar-brand href="#">NavBar</b-navbar-brand>

    <b-navbar-toggle target="nav-collapse"></b-navbar-toggle>

    <b-collapse id="nav-collapse" is-nav>
      <b-navbar-nav>
        <b-nav-item href="#">Link</b-nav-item>
        <b-nav-item href="#" disabled>Disabled</b-nav-item>
      </b-navbar-nav>

      <!-- Right aligned nav items -->
      <b-navbar-nav class="ml-auto">
        <b-nav-form>
          <b-form-input size="sm" class="mr-sm-2" placeholder="Search"></b-form-input>
          <b-button size="sm" class="my-2 my-sm-0" type="submit">Search</b-button>
        </b-nav-form>

        <b-nav-item-dropdown text="Lang" right>
          <b-dropdown-item href="#">EN</b-dropdown-item>
          <b-dropdown-item href="#">ES</b-dropdown-item>
          <b-dropdown-item href="#">RU</b-dropdown-item>
          <b-dropdown-item href="#">FA</b-dropdown-item>
        </b-nav-item-dropdown>

        <b-nav-item-dropdown right>
          <!-- Using 'button-content' slot -->
          <template #button-content>
            <em>User</em>
          </template>
          <b-dropdown-item href="#">Profile</b-dropdown-item>
          <b-dropdown-item href="#">Sign Out</b-dropdown-item>
        </b-nav-item-dropdown>
      </b-navbar-nav>
    </b-collapse>
  </b-navbar>
</div>

<!-- b-navbar.vue -->
```

## Color schemes

`<b-navbar>` supports the standard Bootstrap v4 available background color variants. Set the
`variant` prop to one of the following values to change the background color: `primary`, `success`,
`info`, `warning`, `danger`, `dark`, or `light`.

Control the text color by setting `type` prop to `light` for use with light background color
variants, or `dark` for dark background color variants.

## Placement

Control the placement of the navbar by setting one of two props:

| prop     | type    | default | description                                                                                                                              |
| -------- | ------- | ------- | ---------------------------------------------------------------------------------------------------------------------------------------- |
| `fixed`  | String  | `null`  | Set to `top` for fixed to the top of the viewport, or `bottom` for fixed to the `bottom` of the viewport.                                |
| `sticky` | Boolean | `false` | Set to `true` to make the navbar stick to the top of the viewport (or parent container that has `position: relative` set) when scrolled. |

**Notes:**

- Fixed positioning uses CSS `position: fixed`. You may need to adjust your document top/bottom
  padding or margin.
- CSS `position: sticky` (used for `sticky`) is not fully supported in every browser. For browsers
  that do not support `position: sticky`, it will fallback natively to `position: relative`.

## Supported content

Navbars come with built-in support for a handful of sub-components. Choose from the following as
needed:

- `<b-navbar-brand>` for your company, product, or project name.
- `<b-navbar-toggle>` for use with the `<b-collapse is-nav>` component.
- `<b-collapse is-nav>` for grouping and hiding navbar contents by a parent breakpoint.
- `<b-navbar-nav>` for a full-height and lightweight navigation (including support for dropdowns).
  The following sub-components inside `<b-navbar-nav>` are supported:
  - `<b-nav-item>` for link (and router-link) action items
  - `<b-nav-item-dropdown>` for nav dropdown menus
  - `<b-nav-text>` for adding vertically centered strings of text.
  - `<b-nav-form>` for any form controls and actions.

### `<b-navbar-brand>`

The `<b-navbar-brand>` generates a link if `href` is provided, or a `<router-link>` if `to` is
provided. If neither is given it renders as a `<div>` tag. You can override the tag type by setting
the `tag` prop to the element you would like rendered:

```html
<div>
  <!-- As a link -->
  <b-navbar variant="faded" type="light">
    <b-navbar-brand href="#">BootstrapVue</b-navbar-brand>
  </b-navbar>
</div>

<!-- b-navbar-brand-link.vue -->
```

```html
<div>
  <!-- As a heading -->
  <b-navbar variant="faded" type="light">
    <b-navbar-brand tag="h1" class="mb-0">BootstrapVue</b-navbar-brand>
  </b-navbar>
</div>

<!-- b-navbar-brand-heading.vue -->
```

Adding images to the `<b-navbar-brand>` will likely always require custom styles or utilities to
properly size. Here are some examples to demonstrate:

```html
<div>
  <!-- Just an image -->
  <b-navbar variant="faded" type="light">
    <b-navbar-brand href="#">
      <img src="https://placekitten.com/g/30/30" alt="Kitten">
    </b-navbar-brand>
  </b-navbar>
</div>

<!-- b-navbar-brand-image.vue -->
```

```html
<div>
  <!-- Image and text -->
  <b-navbar variant="faded" type="light">
    <b-navbar-brand href="#">
      <img src="https://placekitten.com/g/30/30" class="d-inline-block align-top" alt="Kitten">
      BootstrapVue
    </b-navbar-brand>
  </b-navbar>
</div>

<!-- b-navbar-brand-image-and-text.vue -->
```

### `<b-navbar-nav>`

Navbar navigation links build on the `<b-navbar-nav>` parent component and requires the use of
`<b-collapse is-nav>` and `<b-nav-toggle>` toggler for proper responsive styling. Navigation in
navbars will also grow to occupy as much horizontal space as possible to keep your navbar contents
securely aligned.

`<b-navbar-nav>` supports the following child components:

- `<b-nav-item>` for link (and router-link) action items
- `<b-nav-text>` for adding vertically centered strings of text.
- `<b-nav-item-dropdown>` for navbar dropdown menus
- `<b-nav-form>` for adding simple forms to the navbar.

### `<b-nav-item>`

`<b-nav-item>` is the primary link (and `<router-link>`) component. Providing a `to` prop value will
generate a `<router-link>` while providing an `href` prop value will generate a standard link.

Set the `<b-nav-item>` `active` prop will highlight the item as being the active page, Disable a
`<b-nav-item>` by setting the prop `disabled` to true.

Handle click events by specifying a handler for the `@click` event on `<b-nav-item>`.

### `<b-nav-text>`

Navbars may contain bits of text with the help of `<b-nav-text>`. This component adjusts vertical
alignment and horizontal spacing for strings of text.

```html
<div>
  <b-navbar toggleable="sm" type="light" variant="light">
    <b-navbar-toggle target="nav-text-collapse"></b-navbar-toggle>

    <b-navbar-brand>BootstrapVue</b-navbar-brand>

    <b-collapse id="nav-text-collapse" is-nav>
      <b-navbar-nav>
        <b-nav-text>Navbar text</b-nav-text>
      </b-navbar-nav>
    </b-collapse>
  </b-navbar>
</div>

<!-- b-navbar-text.vue -->
```

### `<b-nav-item-dropdown>`

For `<b-nav-item-dropdown>` usage, see the [`<b-dropdown>`](/docs/components/dropdown) docs. Note
split dropdowns are not supported in `<b-navbar>` and `<b-navbar-nav>`.

```html
<div>
  <b-navbar type="dark" variant="dark">
    <b-navbar-nav>
      <b-nav-item href="#">Home</b-nav-item>

      <!-- Navbar dropdowns -->
      <b-nav-item-dropdown text="Lang" right>
        <b-dropdown-item href="#">EN</b-dropdown-item>
        <b-dropdown-item href="#">ES</b-dropdown-item>
        <b-dropdown-item href="#">RU</b-dropdown-item>
        <b-dropdown-item href="#">FA</b-dropdown-item>
      </b-nav-item-dropdown>

      <b-nav-item-dropdown text="User" right>
        <b-dropdown-item href="#">Account</b-dropdown-item>
        <b-dropdown-item href="#">Settings</b-dropdown-item>
      </b-nav-item-dropdown>
    </b-navbar-nav>
  </b-navbar>
</div>

<!-- b-navbar-dropdown.vue -->
```

### `<b-nav-form>`

Use `<b-nav-form>` to place inline form controls into your navbar

```html
<div>
  <b-navbar type="light" variant="light">
    <b-nav-form>
      <b-form-input class="mr-sm-2" placeholder="Search"></b-form-input>
      <b-button variant="outline-success" class="my-2 my-sm-0" type="submit">Search</b-button>
    </b-nav-form>
  </b-navbar>
</div>

<!-- b-navbar-form.vue -->
```

Input Groups work as well:

```html
<div>
  <b-navbar type="light" variant="light">
    <b-nav-form>
      <b-input-group prepend="@">
        <b-form-input placeholder="Username"></b-form-input>
      </b-input-group>
    </b-nav-form>
  </b-navbar>
</div>

<!-- b-navbar-form-inputs.vue -->
```

### `<b-navbar-toggle>` and `<b-collapse is-nav>`

Navbars are not responsive by default, but you can easily modify them to change that. Responsive
behavior depends on our `<b-collapse>` component.

Wrap `<b-navbar-nav>` components in a `<b-collapse is-nav>` (**remember to set the `is-nav` prop!**)
to specify content that will collapse based on a particular breakpoint. Assign a document unique
`id` value on the `<b-collapse>`.

Use the `<b-navbar-toggle>` component to control the collapse component, and set the `target` prop
of `<b-navbar-toggle>` to the `id` of `<b-collapse>`.

Set the `toggleable` prop on `<b-navbar>` to the desired breakpoint you would like content to
automatically expand at. Possible `toggleable` values are `sm`, `md`, `lg` and `xl`. Setting
`toggleable` to `true` (or an empty string) will set the navbar to be always collapsed, while
setting it to `false` (the default) will disable collapsing (always expanded).

`<b-navbar-toggle>` components are left-aligned by default, but should they follow a sibling element
like `<b-navbar-brand>`, they'll automatically be aligned to the far right. Reversing your markup
will reverse the placement of the toggler.

See the first example on this page for reference, and also refer to
[`<b-collapse>`](/docs/components/collapse) for details on the collapse component.

Besides being used to control a collapse, the `<b-navbar-toggle>` can also be used to toggle
visibility of the [`<b-sidebar>`](/docs/components/sidebar) component. Just specify the ID of the
`<b-sidebar>` via the `target` prop.

Internally, `<b-navbar-toggle>` uses the [`v-b-toggle` directive](/docs/directives/toggle).

#### Custom navbar toggle

`<b-navbar-toggle>` renders the default Bootstrap v4 _hamburger_ (which is a background SVG image).
You can supply your own content (such as an icon) via the optionally scoped `default` slot. The
default slot scope contains the property `expanded`, which will be `true` when the collapse is
expanded, or `false` when the collapse is collapsed.

Note that the `expanded` scope property only works when supplying the `target` prop as a `string`,
and not an `array`.

```html
<template>
  <b-navbar toggleable type="dark" variant="dark">
    <b-navbar-brand href="#">NavBar</b-navbar-brand>

    <b-navbar-toggle target="navbar-toggle-collapse">
      <template #default="{ expanded }">
        <b-icon v-if="expanded" icon="chevron-bar-up"></b-icon>
        <b-icon v-else icon="chevron-bar-down"></b-icon>
      </template>
    </b-navbar-toggle>

    <b-collapse id="navbar-toggle-collapse" is-nav>
      <b-navbar-nav class="ml-auto">
        <b-nav-item href="#">Link 1</b-nav-item>
        <b-nav-item href="#">Link 2</b-nav-item>
        <b-nav-item href="#" disabled>Disabled</b-nav-item>
      </b-navbar-nav>
    </b-collapse>
  </b-navbar>
</template>
<!-- b-navbar-toggle-slot.vue -->
```

## Printing

Navbars are hidden by default when printing. Force them to be printed by setting the `print` prop.

## See also

- [`<b-collapse>` component](/docs/components/collapse)
- [`<b-sidebar>` component](/docs/components/sidebar)
- [`v-b-toggle` directive](/docs/directives/toggle)
- [`<b-nav>` documentation](/docs/components/nav) for additional components and sub-component
  aliases

Refer to the [Router support](/docs/reference/router-links) reference page for router-link specific
props.

<!-- Component reference added automatically from component package.json -->