Morningstar Design System

Top Hats

Variations Design Guidelines Code Reference Accessibility

Top Hats

  • HTML/CSS Available
  • Web Component Beta
  • Last Updated

    2.17.0

Top Hats display a system-level message above a page’s masthead. There are three types: error, warning, or informational.

Variations Design Guidelines Code Reference Accessibility

Top Hat

Anatomy

Name
Required
Description

Message

Yes

Top hat content.

Type

Yes

Affects the color and icon associated with the top hat. Choose from error, warning, or informational.

Dismiss Action

No

Enables the user to remove the top hat from view.

Variations

Error

Use for system-level errors that prohibit work, such as a critical browser incompatibility or an internet-connectivity issue.

Default
Default
No internet connection. Please check your local network.
HTML Web Component 
<diV class="mds-top-hat mds-top-hat--error" role="alert">
    <div class="mds-top-hat__body">
        <svg class="mds-icon mds-top-hat__icon" aria-hidden="true">
            <use xlink:href="/icons/mds.svg#alert">
            </use>
        </svg>
        <span class="mds-top-hat__message">No internet connection. Please check your local network.</span>
    </div>
</diV>
<mds-top-hat variation="error" dismissible="false" role="alert">No internet connection. Please check your local network.</mds-top-hat>
  • Don’t allow an error to be dismissed. Instead, help a user understand how to fix the problem and dismiss the error automatically once it’s resolved.

Warning

Use to provide a system-level warning, such as a permissions or data issue, planned outages, or a non-critical browser incompatibility.

Default
Default
Service will be unavailable on Sunday, December 10th from 5–7 PM CST for scheduled maintenance. More information
HTML Web Component 
<diV class="mds-top-hat mds-top-hat--warning mds-top-hat--dismissible" role="alert">
    <div class="mds-top-hat__body">
        <svg class="mds-icon mds-top-hat__icon" aria-hidden="true">
            <use xlink:href="/icons/mds.svg#alert">
            </use>
        </svg>
        <span class="mds-top-hat__message">Service will be unavailable on Sunday, December 10th from 5–7 PM CST for scheduled maintenance. <a href='#'>More information</a>
        </span>
    </div>
    <button class="mds-button mds-button--small mds-button--icon-only mds-top-hat__dismiss-button" type="button">
        <svg class="mds-icon mds-button__icon mds-button__icon--right" aria-hidden="true">
            <use xlink:href="/icons/mds.svg#remove--s">
            </use>
        </svg>
    </button>
</diV>
<mds-top-hat variation="warning" role="alertdialog">Service will be unavailable on Sunday, December 10th from 5–7 PM CST for scheduled maintenance. <mds-link href='#'>More information</mds-link>
</mds-top-hat>
  • Optionally, omit the dismiss action, and persist the warning until it is resolved.

Informational

Use to provide system-level information, such as an announcement about a new feature.

Default
Default
Welcome to the new Morningstar.com. See What’s New
HTML Web Component 
<diV class="mds-top-hat mds-top-hat--dismissible" role="alert">
    <div class="mds-top-hat__body">
        <svg class="mds-icon mds-top-hat__icon" aria-hidden="true">
            <use xlink:href="/icons/mds.svg#info-circle">
            </use>
        </svg>
        <span class="mds-top-hat__message">Welcome to the new Morningstar.com. <a href='#'>See What’s New</a>
        </span>
    </div>
    <button class="mds-button mds-button--small mds-button--icon-only mds-top-hat__dismiss-button" type="button">
        <svg class="mds-icon mds-button__icon mds-button__icon--right" aria-hidden="true">
            <use xlink:href="/icons/mds.svg#remove--s">
            </use>
        </svg>
    </button>
</diV>
<mds-top-hat role="alertdialog">Welcome to the new Morningstar.com. <mds-link href='#'>See What’s New</mds-link>
</mds-top-hat>

Sizing

Sizing affects text size, icon size, and internal padding. Use small top hats when vertical space is limited or information density is desired. The default size is small and you can use modifier classes or props to make the top hat smaller.

Small
Medium (Default)
Small
Top hat message, including a link.
Medium (Default)
Top hat message, including a link.
HTML Web Component 
<diV class="mds-top-hat mds-top-hat--small mds-top-hat--dismissible" role="alert">
    <div class="mds-top-hat__body">
        <svg class="mds-icon mds-top-hat__icon" aria-hidden="true">
            <use xlink:href="/icons/mds.svg#info-circle--s">
            </use>
        </svg>
        <span class="mds-top-hat__message">Top hat message, including <a href='#'>a link</a>.</span>
    </div>
    <button class="mds-button mds-button--small mds-button--icon-only mds-top-hat__dismiss-button" type="button">
        <svg class="mds-icon mds-button__icon mds-button__icon--right" aria-hidden="true">
            <use xlink:href="/icons/mds.svg#remove--s">
            </use>
        </svg>
    </button>
</diV>
<mds-top-hat size="small" role="alertdialog">Top hat message, including <a href='#'>a link</a>.</mds-top-hat>

Use When

  • Providing a user system-level errors, warnings and information.

Don’t Use When

  • Providing a user with a message related to a page-level or out-of-view event, like completion of a report generation. Instead, use a Notification.
  • Providing a user with a message related to a specific element on the current page, like a summary of errors in a form. Instead, use an Alert.

Visual Language

Top hat placement stays the same regardless of page width.
  • Place above the page’s Masthead.
  • Stretches horizontally to fill 100% of viewport width.
A maximum width for top hat message and icon is 500px. The top hat background spans the width of the page.
  • To ensure content doesn’t exceed Typography line-length guidelines, top hats limit the maximum width of the message and icon to 500px.
    • The dismiss action can fall outside of this maximum content width.

Behaviors

  • Never include a dismiss action in Errors. Instead, dismiss automatically once the error is resolved.
  • When applicable, dismiss by clicking the Icon-Only Button with a close icon, remove--s.
  • The top hat stays on the Masthead. If the Masthead sticks as a user scrolls down the page, then the top hat goes along for the ride.
  • A page can only wear one kind of top hat at a time.
  • When dismissed or resolved, top hats slide up and fade out, relinquishing their space.

Editorial

  • Keep it brief—aim for fewer than 10 words.
  • Use full sentences and punctuation. Use sentence case.
  • Use figures instead of spelling out numbers.
  • Top hats can include links. Don’t use “click here,” “tap this link,” etc., inside link copy. Link copy should be device agnostic—a user may not have a mouse with which to click or the capability to tap.
  • Use “!” sparingly, as it conflicts with the informational icon, and is generally unnecessary.

CSS

Class References

Class
Applies to
Outcome

mds-top-hat--small

mds-top-hat

Reduces text size, icon size, and internal padding.

mds-top-hat--dismissible

mds-top-hat

Adds padding to the right side of the body of the top hat to accommodate the close icon.

mds-top-hat--is-dismissed

mds-top-hat

Dismisses the top hat by animating fade-out and slide-up effects.

mds-top-hat--warning

mds-top-hat

Applies the yellow color to the component’s background, bottom border, and icon.

mds-top-hat--error

mds-top-hat

Applies the red color to the component’s background, bottom border, and icon.

Web Component

Props

When setting props as attributes on a custom HTML element, use kebab-case instead of camelCase.

Prop
Type
Validation
Default
Description

additionalClass

String

—

—

A space-separated list of class names that will be appended to the default mds-top-hat class.

dismissible

Boolean

—

true

If true, adds an icon-only dismiss button that allows the top hat to be dismissed.

removable

Boolean

Only valid when dismissible is set to true

true

When true, removes the top hat from the DOM after the dismiss animation completes. If false, top hat is simply hidden when dismissed, not removed.

role

String

—

—

Sets the role attribute. See accessibility for more information.

size

String

One of: small, medium

medium

Alters the size of the top hat.

variation

String

One of: error, warning, informational

informational

Sets the variation of the top hat.

text

String

Required

—

The text for the top hat. Can also be passed via the default slot.

Slots

Default Slot

Pass text in between the <mds-top-hat></mds-top-hat> tags to set the top hat’s text. This can be overridden with the text prop.

Methods

Method Name
Description

dismiss(removeAfterDismissal = this.removable || true)

The same method called internally when the icon-only dismiss button is clicked. Useful for programmatically calling dismiss() based on an interaction besides a user clicking the dismiss button in the top hat itself.

Events

Event Name
Description

mds-top-hat-dismissed

If dismissible is true, this custom event will trigger after the top hat has visibly disappeared.

mds-top-hat-removed

If removable is true, this custom event will trigger after the top hat is removed from the DOM.

Usage Examples

Setting size and role via props. Using the default slot for text content:

<mds-top-hat size="small" role="alertdialog">
    This is a sample top hat message.
</mds-top-hat>

Setting text, variation, role, and dismissible via props:

<mds-top-hat text="You don’t have an internet connection." variation="error" dismissible="false" role="alert"></mds-top-hat>

Implementation

  • Use role="alert" for top hats that do not contain an interactive element.
  • Use role="alertdialog" when a top hat includes an interactive element, like a Link or dismiss button.
    • When triggered, assign focus to the most relevant interactive element in the top hat.