Open Source DOM Component

The Lineup

All the usual suspects

Motivation

Sometimes a visual menu is better than a textual menu.

The rwt-lineup DOM component applies circular styling to square images, providing a fully iconic interface. For situations where there are too many hyperlinks to fit in a single line, the extras are kept hidden until activated by the user, using either the visual pullbar or the component's toggleMenu method or through its event interface.

This component is a light-hearted take on "The Line Up" of "all the usual suspects". It's designed for use in a website's top banner area.

The component has these features:

• A single line of icons is displayed in the container's collapsed state. The full set of icons is display in the expanded state, accommodating any number of menu items.
• The menu item corresponding to the current page is highlighted and scrolled into view when the page is loaded.
• The menu has an event interface for expanding and collapsing itself.
• The menu emits a custom event to close sibling menus and dialog boxes.
• Menu items may be kept separate from the DOM component, allowing the webmaster to change its contents in a single centralized place. Alternatively, menu items may be slotted directly between the component's opening and closing tags.
• A keyboard listener is provided to allow a shortcut key to expand/collapse the menu.
• A half-height pullbar for expanding the container is displayed along the bottom margin, appearing larger on hover.
• The first few times that a visitor interacts with your website, the pullbar pulses to draw attention to itself.

In the wild

To see an example of this component in use, visit the DOPPELMARKS website. It uses this component at the top of the page. To understand what's going on under the hood, use the browser's inspector to view the HTML source code and network activity, and follow along as you read this documentation.

Installation

Prerequisites

The rwt-lineup DOM component works in any browser that supports modern W3C standards. Templates are written using BLUE PHRASE notation, which can be compiled into HTML using the free Read Write View desktop app. It has no other prerequisites. Distribution and installation are done with either NPM or via Github.

Download

Using the DOM component

After installation, you need to add two things to your HTML page to make use of it.

• Add a script tag to load the component's rwt-lineup.js file:

<script src='/node_modules/rwt-lineup/rwt-lineup.js' type=module></script>             

• Add the component tag somewhere on the page.

  • For scripting purposes, apply an id attribute.
  • Apply a sourceref attribute with a reference to an HTML file containing the menu's hyperlinks.
  • Optionally, apply a shortcut attribute with something like F9, F10, etc. for hotkey access.
  • For WAI-ARIA accessibility apply a role=navigation attribute.
  • For simple menus, the sourceref may be omitted and the menu hyperlinks may be slotted into the DOM component. Simply place the hyperlinks directly between the <rwt-lineup> and </rwt-lineup> tags.
  • Here's an example HTML tag where the menu items are in a separate file:

<rwt-lineup id=lineup sourceref='/menu.html' shortcut=F10 role=navigation></rwt-lineup>

Menu template

The content and format of the menu items should follow this pattern, which uses anchors <a> that enclose images <img>.

<a href='/path/to/page1.html' tabindex=301 <img src='/img/page1.jpg' title='Page 1' ></a>
<a href='/path/to/page2.html' tabindex=301 <img src='/img/page2.jpg' title='Page 2' ></a>
<a href='/path/to/page3.html' tabindex=301 <img src='/img/page3.jpg' title='Page 3' ></a>

Self identification

The menu item corresponding to the current page can be highlighted when it identifies itself to the menu. This is accomplished by adding a meta tag to the page that contains the short-form URL of the page itself. For example, if the page's full URL is https://example.com:443/services.html the shortform URL would be /services.html.

The short-form URL should be added to a special-purpose meta tag, like this:

<meta name='lineup:this-url' content='/services.html' />

Customization

Menu item size and spacing

The images that you provide should be square. They will be resized using the value you specify with the CSS --img-size variable. Spacing between the icons can be adjusted with the --img-margin variable.

The height of the pullbar can be made more or less prominent by setting the --pullbar-height variable.

The --width variable can be used to shorten the width of the component's inner container.

rwt-lineup {
    --img-size: 64px;
    --img-margin: 16px;
    --width: 100%;
    --pullbar-height: 1rem;
}

Menu color scheme

The default color palette for the menu uses a dark mode theme. You can use CSS to override the variables' defaults:

rwt-lineup {
    --color: var(--pure-white);
    --accent-color1: var(--title-blue);
    --accent-color2: var(--yellow);
    --accent-color3: var(--dark-gray);
    --background: var(--transparent-black);
    --accent-background1: var(--light-black);
    --accent-background2: var(--pure-black);
}

Life-cycle events

The component issues life-cycle events.

Event controllers

The menu can be controlled with its event interface.

Reference

License

The rwt-lineup DOM component is licensed under the MIT License.