Infotip Button
Reveals helpful information about a nearby non-interactive element or region of a page.
Helping user with form
Infofip Button is a click-activated flyout. It discloses supplementary or advisory content about an existing onscreen element or region.
Thematically, you can think of the infotip content fulfilling the same role as footnotes in a page.
Infotip Button is a composite pattern containing a button and an overlay. The button toggles the visibility of the overlay. The overlay contains the help content.
We use the following terminology when discussing this pattern.
- infotip: the pattern as a whole, comprised of the following sub-parts
- button: the button that hosts the overlay
- overlay/bubble: the overlay that contains the tip
- pointer: the visual affordance that "points" to the button
- tip: the tip content
- expanded: an infotip with expanded overlay
- collapsed: an infotip with collapsed overlay
On desktop screens, overlay must not be modal. On smaller screens, the overlay may be implemented as a modal dialog.
Button must not have overlay content duplicated within an
aria-describedby attribute.Button must not have
aria-haspopup attribute. Despite the name of this property, it is actually intended specifically for a Menu.The infotip must remain expanded until explicitly closed with the close button or programmatically closed by another component (e.g. when another nearby infotip opens).
Users sometimes have a need to reference the infotip content whilst working on a task (e.g. filling out a form field), this is why we must not collapse the infotip on mouseout, blur or page click.
Overlay should be hidden by default. If you wish to display a tip on page load, consider the Tourtip.
Overlay content should be no more than one or two paragraphs in length. For lengthier content, consider instead using a dialog.
This section provides the pattern interaction design for keyboard, screen reader & pointing devices.
Button must be keyboard focusable.
Activating button must toggle the expanded state of the overlay. Keyboard focus should remain on the button.
If overlay contains focusable elements, tab order must flow directly from button to first of those elements.
If the overlay has no focusable elements, tab order must flow directly to next page control.
Button purpose must be announced (e.g. 'Help).
Button state must be announced (i.e. expanded or collapsed).
Reading order must flow directly from button into overlay.
Expanded state must be announced after expanded.
Invoking button must toggle the expanded state of the overlay.
This implementation will get us quickly up and running with the accessibility requirements of an infotip.
The goal of our content layer is to add the button and overlay. The structure and DOM positioning of these elements is of utmost importance so that keyboard tabbing order and screen reader both naturally flow into the overlay.
<span class="infotip" id="infotip-0">
<button class="infotip__host" aria-controls="infotip-0-overlay" aria-expanded="false" aria-label="Help" type="button"></button>
<span class="infotip__live-region" aria-live="off">
<div class="infotip__overlay" id="infotip-0-overlay">
<!-- overlay content -->
</div>
</span>
</span>
Notice placement of the button directly before the live-region element. This allows natural tab order flow and screen reading order from the button into the overlay.
The live-region property is set to "off". This is a matter of preference. Some people prefer the new content to announce when it appears, using a setting of "polite". At eBay we have this set to
off; we rely on the aria-expanded state as being the affordance that there is new content in the reading order.The goal of the CSS layer is to hide or show the overlay depending on the aria-expanded state.
.infotip {
position: relative;
}
.infotip__overlay {
display: none;
position: absolute;
white-space: nowrap;
z-index: 1;
}
.infotip__host[aria-expanded=true] ~ .infotip__live-region .infotip__overlay {
display: block;
}
The overlay must have
display: none when in a collapsed state to ensure that screen readers cannot access the overlay content. You may also wish to leverage the hidden property instead.For a progressive enhancement approach, you may choose to have all infotip content visible by default, and then hide it when JavaScript becomes available. This can however result in a flash of unstyled content (FOUC).
CSS alone cannot change the value of an aria attribute; we require JavaScript. Fortunately, the makeup-expander module can handle this behaviour for us in just a few lines of code.
const Expander = require('makeup-expander');
const widget = new Expander(widgetEl, {
contentSelector: '.infotip__content',
expandOnClick: true,
collapseOnClick: true,
hostSelector: '.infotip__host'
});
Clicking the button with mouse or keyboard will now toggle the aria-expanded state of the button.
Animations are also possible of course, but fall outside the scope of this book.
The following JavaScript modules may assist you in creation of an infotip pattern:
- makeup-expander: handles some basic accessibility for an element that expands and collapses another element.
Informs assistive technology to announce the overlay contents whenever the button changes from collapsed to expanded (optional/opinionated).
Provides an accessible button label/name for the icon button.
Informs assistive technology of the expanded state of the button.
A tooltip provides a tip about the primary action of an interactive element (typically a button). For example, the trashcan icon button in your mail application. The tooltip can be thought of as the secondary action of the button. It is always triggered by focus and hover.
An infotip button provides a tip about a nearby static element or content. It is always triggered by click.
The fundamental difference is that the Bootstrap Popovers get their content from a data attribute, whereas the pattern presented here gets it's content from an actual element. This allows us to more easily place HTML such as hyperlinks & images inside of our popovers and, unlike Bootstrap, the popover content can be fully accessible without JavaScript (assuming you choose to make the content visible by default).
Last modified 7mo ago