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Bootstrap/site/docs/4.2/components/navbar.md
Mark Otto eda851ee76 Prep for v4.2.0 release
- Move 4.1 docs to 4.2
- Update versions everywhere to 4.1.3 with release script
- Manually bump the shorthand version in package.json
- Add 4.2 to the versions docs page
- Update some redirects
- Fix tests asset URLs
- Bump Nuget and more
2018-12-21 09:03:29 -08:00

24 KiB

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docs Navbar Documentation and examples for Bootstrap's powerful, responsive navigation header, the navbar. Includes support for branding, navigation, and more, including support for our collapse plugin. components true

How it works

Here's what you need to know before getting started with the navbar:

  • Navbars require a wrapping .navbar with .navbar-expand{-sm|-md|-lg|-xl} for responsive collapsing and color scheme classes.
  • Navbars and their contents are fluid by default. Use optional containers to limit their horizontal width.
  • Use our [spacing]({{ site.baseurl }}/docs/{{ site.docs_version }}/utilities/spacing/) and [flex]({{ site.baseurl }}/docs/{{ site.docs_version }}/utilities/flex/) utility classes for controlling spacing and alignment within navbars.
  • Navbars are responsive by default, but you can easily modify them to change that. Responsive behavior depends on our Collapse JavaScript plugin.
  • Navbars are hidden by default when printing. Force them to be printed by adding .d-print to the .navbar. See the [display]({{ site.baseurl }}/docs/{{ site.docs_version }}/utilities/display/) utility class.
  • Ensure accessibility by using a <nav> element or, if using a more generic element such as a <div>, add a role="navigation" to every navbar to explicitly identify it as a landmark region for users of assistive technologies.

{% include callout-info-prefersreducedmotion.md %}

Read on for an example and list of supported sub-components.

Supported content

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

  • .navbar-brand for your company, product, or project name.
  • .navbar-nav for a full-height and lightweight navigation (including support for dropdowns).
  • .navbar-toggler for use with our collapse plugin and other navigation toggling behaviors.
  • .form-inline for any form controls and actions.
  • .navbar-text for adding vertically centered strings of text.
  • .collapse.navbar-collapse for grouping and hiding navbar contents by a parent breakpoint.

Here's an example of all the sub-components included in a responsive light-themed navbar that automatically collapses at the lg (large) breakpoint.

{% capture example %}

Navbar {% endcapture %} {% include example.html content=example %}

This example uses [color]({{ site.baseurl }}/docs/{{ site.docs_version }}/utilities/colors/) (bg-light) and [spacing]({{ site.baseurl }}/docs/{{ site.docs_version }}/utilities/spacing/) (my-2, my-lg-0, mr-sm-0, my-sm-0) utility classes.

Brand

The .navbar-brand can be applied to most elements, but an anchor works best as some elements might require utility classes or custom styles.

{% capture example %}

Navbar Navbar {% endcapture %} {% include example.html content=example %}

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

{% capture example %}

{% endcapture %} {% include example.html content=example %}

{% capture example %}

Bootstrap {% endcapture %} {% include example.html content=example %}

Nav

Navbar navigation links build on our .nav options with their own modifier class and require the use of toggler classes 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.

Active states—with .active—to indicate the current page can be applied directly to .nav-links or their immediate parent .nav-items.

{% capture example %}

Navbar {% endcapture %} {% include example.html content=example %}

And because we use classes for our navs, you can avoid the list-based approach entirely if you like.

{% capture example %}

Navbar {% endcapture %} {% include example.html content=example %}

You may also utilize dropdowns in your navbar nav. Dropdown menus require a wrapping element for positioning, so be sure to use separate and nested elements for .nav-item and .nav-link as shown below.

{% capture example %}

Navbar {% endcapture %} {% include example.html content=example %}

Forms

Place various form controls and components within a navbar with .form-inline.

{% capture example %}

Search {% endcapture %} {% include example.html content=example %}

Immediate children elements in .navbar use flex layout and will default to justify-content: between. Use additional [flex utilities]({{ site.baseurl }}/docs/{{ site.docs_version }}/utilities/flex/) as needed to adjust this behavior.

{% capture example %}

Navbar Search {% endcapture %} {% include example.html content=example %}

Input groups work, too:

{% capture example %}

@
{% endcapture %} {% include example.html content=example %}

Various buttons are supported as part of these navbar forms, too. This is also a great reminder that vertical alignment utilities can be used to align different sized elements.

{% capture example %}

Main button Smaller button {% endcapture %} {% include example.html content=example %}

Text

Navbars may contain bits of text with the help of .navbar-text. This class adjusts vertical alignment and horizontal spacing for strings of text.

{% capture example %}

Navbar text with an inline element {% endcapture %} {% include example.html content=example %}

Mix and match with other components and utilities as needed.

{% capture example %}

Navbar w/ text
Navbar text with an inline element
{% endcapture %} {% include example.html content=example %}

Color schemes

Theming the navbar has never been easier thanks to the combination of theming classes and background-color utilities. Choose from .navbar-light for use with light background colors, or .navbar-dark for dark background colors. Then, customize with .bg-* utilities.

Navbar
<div class="collapse navbar-collapse" id="navbarColor01">
  <ul class="navbar-nav mr-auto">
    <li class="nav-item active">
      <a class="nav-link" href="#">Home <span class="sr-only">(current)</span></a>
    </li>
    <li class="nav-item">
      <a class="nav-link" href="#">Features</a>
    </li>
    <li class="nav-item">
      <a class="nav-link" href="#">Pricing</a>
    </li>
    <li class="nav-item">
      <a class="nav-link" href="#">About</a>
    </li>
  </ul>
  <form class="form-inline">
    <input class="form-control mr-sm-2" type="search" placeholder="Search" aria-label="Search">
    <button class="btn btn-outline-info my-2 my-sm-0" type="submit">Search</button>
  </form>
</div>
Navbar
<div class="collapse navbar-collapse" id="navbarColor02">
  <ul class="navbar-nav mr-auto">
    <li class="nav-item active">
      <a class="nav-link" href="#">Home <span class="sr-only">(current)</span></a>
    </li>
    <li class="nav-item">
      <a class="nav-link" href="#">Features</a>
    </li>
    <li class="nav-item">
      <a class="nav-link" href="#">Pricing</a>
    </li>
    <li class="nav-item">
      <a class="nav-link" href="#">About</a>
    </li>
  </ul>
  <form class="form-inline">
    <input class="form-control mr-sm-2" type="search" placeholder="Search" aria-label="Search">
    <button class="btn btn-outline-light my-2 my-sm-0" type="submit">Search</button>
  </form>
</div>
Navbar
<div class="collapse navbar-collapse" id="navbarColor03">
  <ul class="navbar-nav mr-auto">
    <li class="nav-item active">
      <a class="nav-link" href="#">Home <span class="sr-only">(current)</span></a>
    </li>
    <li class="nav-item">
      <a class="nav-link" href="#">Features</a>
    </li>
    <li class="nav-item">
      <a class="nav-link" href="#">Pricing</a>
    </li>
    <li class="nav-item">
      <a class="nav-link" href="#">About</a>
    </li>
  </ul>
  <form class="form-inline">
    <input class="form-control mr-sm-2" type="search" placeholder="Search" aria-label="Search">
    <button class="btn btn-outline-primary my-2 my-sm-0" type="submit">Search</button>
  </form>
</div>

{% highlight html %}

{% endhighlight %}

Containers

Although it's not required, you can wrap a navbar in a .container to center it on a page or add one within to only center the contents of a fixed or static top navbar.

{% capture example %}

{% endcapture %} {% include example.html content=example %}

When the container is within your navbar, its horizontal padding is removed at breakpoints lower than your specified .navbar-expand{-sm|-md|-lg|-xl} class. This ensures we're not doubling up on padding unnecessarily on lower viewports when your navbar is collapsed.

{% capture example %}

{% endcapture %} {% include example.html content=example %}

Placement

Use our [position utilities]({{ site.baseurl }}/docs/{{ site.docs_version }}/utilities/position/) to place navbars in non-static positions. Choose from fixed to the top, fixed to the bottom, or stickied to the top (scrolls with the page until it reaches the top, then stays there). Fixed navbars use position: fixed, meaning they're pulled from the normal flow of the DOM and may require custom CSS (e.g., padding-top on the <body>) to prevent overlap with other elements.

Also note that .sticky-top uses position: sticky, which isn't fully supported in every browser.

{% capture example %}

Default {% endcapture %} {% include example.html content=example %}

{% capture example %}

Fixed top {% endcapture %} {% include example.html content=example %}

{% capture example %}

Fixed bottom {% endcapture %} {% include example.html content=example %}

{% capture example %}

Sticky top {% endcapture %} {% include example.html content=example %}

Responsive behaviors

Navbars can utilize .navbar-toggler, .navbar-collapse, and .navbar-expand{-sm|-md|-lg|-xl} classes to change when their content collapses behind a button. In combination with other utilities, you can easily choose when to show or hide particular elements.

For navbars that never collapse, add the .navbar-expand class on the navbar. For navbars that always collapse, don't add any .navbar-expand class.

Toggler

Navbar togglers are left-aligned by default, but should they follow a sibling element like a .navbar-brand, they'll automatically be aligned to the far right. Reversing your markup will reverse the placement of the toggler. Below are examples of different toggle styles.

With no .navbar-brand shown in lowest breakpoint:

{% capture example %}

{% endcapture %} {% include example.html content=example %}

With a brand name shown on the left and toggler on the right:

{% capture example %}

Navbar {% endcapture %} {% include example.html content=example %}

With a toggler on the left and brand name on the right:

{% capture example %}

Navbar {% endcapture %} {% include example.html content=example %}

External content

Sometimes you want to use the collapse plugin to trigger hidden content elsewhere on the page. Because our plugin works on the id and data-target matching, that's easily done!

{% capture example %}

Collapsed content
Toggleable via the navbar brand.
{% endcapture %} {% include example.html content=example %}