WCAG Compliant Responsive Dropdown Navigation – accessible-menu

Preview:

Description:

An accessible, WCAG compliant, fully responsive, multi-level, and mobile-friendly responsive dropdown navbar component written in pure JavaScript.

How to use it:

1. Install and import the accessible-menu as an ES module.

# NPM
$ npm install accessible-menu --save

import AccessibleMenu from 'accessible-menu';

2. Or include the UMD version of the component on the page as follows:

<!-- From Local -->
<script src="/path/to/dist/accessibleMenu.min.js"></script>
<!-- From A CDN -->
<script src="https://cdn.jsdelivr.net/npm/accessible-menu/dist/accessibleMenu.min.js"></script>

3. The HTML structure to create a multi-level (up to two) dropdown menu with a hamburger toggle button for mobile view.

<header>
  <nav id="main-menu" aria-labelledby="main-menu-title">
    <span id="main-menu-title" class="menu-title visually-hidden">Main</span>
    <span class="branding" aria-hidden="true">Accessible Menu</span>
    <button href="" class="menu-toggle">☰<span class="visually-hidden"> Toggle Menu</span></button>
    <ul class="menu">
      <li class="menu-item"><a href="#" class="menu-link">Home</a></li>
      <li class="menu-item"><a href="#" class="menu-link">Contact</a></li>
      <li class="menu-item dropdown">
        <a href="#" class="menu-link dropdown-toggle">JavaScript</a>
        <ul class="menu dropdown">
          <li class="menu-item"><a href="#" class="menu-link">Vanilla</a></li>
          <li class="menu-item dropdown">
            <a href="#" class="menu-link dropdown-toggle">Framework</a>
            <ul class="menu dropdown">
              <li class="menu-item"><a href="#" class="menu-link">Angular</a></li>
              <li class="menu-item"><a href="#" class="menu-link">React</a></li>
              <li class="menu-item"><a href="#" target="_blank" class="menu-link">VueJS</a></li>
            </ul>
          </li>
        </ul>
      </li>
      <li class="menu-item"><a href="#" target="_blank" class="menu-link">Download</a></li>
    </ul>
  </nav>
</header>

4. Initialize the dropdown menu.

const navs = document.querySelectorAll("nav");
const menuSettings = {
      menuItemSelector: ".menu-item",
      submenuItemSelector: ".menu-item.dropdown",
      submenuToggleSelector: ".dropdown-toggle",
      submenuSelector: ".menu.dropdown",
      openClass: "show"
};

navs.forEach(nav => {
  const menuElement = nav.querySelector(".menu");

  if (nav.id === "main-menu") {
    const controllerElement = nav.querySelector(".menu-toggle");
    const menu = new AccessibleMenu({
      menuElement,
      ...menuSettings,
      controllerElement,
      containerElement: nav
    });
  } else {
    const menu = new AccessibleMenu({
      menuElement,
      ...menuSettings
    });
  }
});

5. The example CSS for the dropdown menu.

nav {
  display: flex;
  flex-direction: row;
  flex-wrap: wrap;
  align-items: center;
  background-color: #25585f;
  color: #fff;
}

nav a:focus,
nav button:focus {
  outline: 0.2rem solid #f58a97;
  outline-offset: -0.2rem;
}

h1 {
  font-size: 2rem;
  line-height: 2.1rem;
}

#main-menu>.menu {
  display: none;
  flex-direction: column;
}

#main-menu>.menu.show {
  display: flex;
}

#main-menu>.menu-toggle {
  display: block;
  margin-left: auto;
  background: transparent;
  border: 0;
  color: #fff;
  font-size: 2rem;
  padding: 0.5rem 2rem;
}

#main-menu>.branding {
  display: block;
  font-size: 1.5rem;
  padding: 0.5rem 2rem;
}

@media screen and (max-width: 1069px) {
  #main-menu>.menu {
    width: 100%;
  }
}

@media screen and (min-width: 1070px) {
  #main-menu>.menu {
    display: flex;
    flex-direction: row;
  }
  #main-menu>.menu-toggle {
    display: none;
  }
}

.visually-hidden {
  position: absolute !important;
  width: 1px !important;
  height: 1px !important;
  padding: 0 !important;
  margin: -1px !important;
  overflow: hidden !important;
  clip: rect(0, 0, 0, 0) !important;
  white-space: nowrap !important;
  border: 0 !important;
}

.menu {
  display: flex;
  flex-direction: row;
  background-color: #25585f;
  list-style: none;
  padding: 0;
  margin: 0;
}

.menu.dropdown {
  display: none;
  flex-direction: column;
}

@media screen and (min-width: 1070px) {
  .menu.dropdown li.menu-item .menu.dropdown {
    top: 0;
    left: 100%;
  }
}

@media screen and (max-width: 1069px) {
  .menu .menu .menu-link {
    padding-left: 3rem;
  }
  .menu .menu .menu .menu-link {
    padding-left: 4rem;
  }
}

.menu .menu-link,
.menu .menu-toggle {
  display: block;
  background-color: #25585f;
  color: #fff;
  text-decoration: none;
  border: none;
  padding: 1rem 2rem;
}

.menu .menu-link:hover,
.menu .menu-toggle:hover {
  background-color: #0d464e;
  text-decoration-line: underline;
  text-decoration-color: #f58a97;
  text-decoration-thickness: 0.2rem;
}

.menu .menu-link:active {
  background-color: #f58a97;
  color: #000;
}

.menu .menu-item {
  position: relative;
}

.menu .menu-item.dropdown>.dropdown-toggle::after {
  content: "▼";
  margin-left: 0.5rem;
  display: inline-block;
}

.menu .menu-item.show>.menu.dropdown {
  display: flex;
}

@media screen and (min-width: 1070px) {
  .menu .menu-item.show>.menu.dropdown {
    position: absolute;
    left: 0;
  }
}

6. All possible parameters:

• menuElement: The menu element in the DOM.
• menuItemSelector: The selector string for menu items.
• submenuItemSelector: The selector string for submenu items.
• submenuToggleSelector: The selector string for submenu toggle triggers.
• submenuSelector: The selector string for the submenu itself.
• openClass: The class to use when a submenu is open.
• isTopLevel: A flag to mark the root menu.
• controllerElement: The element controlling the menu in the DOM.
• containerElement: The element containing the menu in the DOM.
• parentMenu: The menu containing this menu.

Changelog:

05/23/2020

• feat(menu): allow for multiple open and close classes

05/20/2020

• fix(ie): add string.prototype.startsWith polyfill

05/09/2020

• fix(events): use touchup and mouseup events instead of click

05/07/2020

• v2.0.0