MessageFeed alpha

AI chat component. This page is the API reference, generated from the source code. Usage guidance and live examples are on the Chinese page.

HeadlessStylesVueReactWeb Components

Anatomy

Parts in bold are required.

data-scope="message-feed": root · viewport · list · item · item-label · separator · pending-indicator · scroll-to-end-trigger · unread-count · live-region

API reference

Descriptions of individual props, events and slots are written in Chinese and appear on the Chinese page.

Artifacts

Layer	Value
Custom element	<xh-message-feed>
Vue components	XhMessageFeedItem XhMessageFeedItemLabel XhMessageFeedList XhMessageFeedLiveRegion XhMessageFeedPendingIndicator XhMessageFeedRoot XhMessageFeedScrollToEndTrigger XhMessageFeedSeparator XhMessageFeedUnreadCount XhMessageFeedViewport
Composable	useMessageFeed
State machine	messageFeedMachine
Skin	@xihan-ui/styles/message-feed.css

Props

Prop	Type	Required
count	number
status	MessageFeedStatus
threshold	number
loop	boolean
size	Size
translations	Partial<MessageFeedTranslations>
onStickChange	(details: MessageFeedStickChangeDetails) => void
onItemFocus	(details: MessageFeedItemFocusDetails) => void

Events

Custom elements put the payload in detail; Vue emits an event of the same name.

Event	Payload
stick-change	MessageFeedStickChangeDetails
item-focus	MessageFeedItemFocusDetails

Slots

Only slots with a payload are listed.

Vue component	Slot	Payload
XhMessageFeedRoot	default	MessageFeedRootSlotProps

React adapter props

Only the props each component declares itself: DOM attributes inherited from ComponentPropsWithRef are left out, and root props already listed in the Props table are not repeated. The Vue counterpart is the slot table above.

React component	Prop	Type	Required
XhMessageFeedItem	itemId	string	Yes
XhMessageFeedItem	itemIndex	number | string	Yes
XhMessageFeedItem	itemRole	MessageFeedItemRole
XhMessageFeedItem	itemStreaming	boolean
XhMessageFeedRoot	children	SlotChildren<MessageFeedRootSlotProps>

State

Public state is written to data-state.

Part	Values
root	props.status
pending-indicator	props.status
scroll-to-end-trigger	'hidden' | 'visible'

The following names are internal to the state machine.

States: idle

Events: STICK.CHANGE · SCROLL_TO_BOTTOM · ITEM.FOCUS · FEED.BLUR · PRESS.START · PRESS.END · ARRIVALS.TRACKED · TRIGGER.RENDERED

Guards: canPress

connect API

getXxxProps() returns the host attributes of the matching part.

Member	Type
status	MessageFeedStatus
atBottom	boolean
sticking	boolean
focusedId	string | null
showScrollToEndTrigger	boolean
unreadCount	number
scrollToBottom	() => void
scrollToItem	(id: string) => void
focusItem	(id: string) => void
getRootProps	() => T['element']
getViewportProps	() => T['element']
getListProps	() => T['element']
getItemProps	(props: MessageFeedItemProps) => T['element']
getItemLabelProps	(props: Pick<MessageFeedItemProps, 'id'>) => T['element']
getScrollToEndTriggerProps	() => T['button']
getUnreadCountProps	() => T['element']
getSeparatorProps	() => T['element']
getPendingIndicatorProps	() => T['element']
getLiveRegionProps	() => T['element']

Accessibility

Keyboard

Specification: W3C APG. Each row is a stable behavior id that the conformance tests cover; the conditions and effects are described on the Chinese page.

Keys	Behavior
PageDown	message-feed.kbd.next
PageUp	message-feed.kbd.prev
Control+End	message-feed.kbd.exit-after
Control+Home	message-feed.kbd.exit-before
Tab	message-feed.kbd.tab
ArrowUp / ArrowDown / Home / End	message-feed.kbd.scroll
Enter / Space	message-feed.kbd.scroll-to-end-trigger
Enter / Space	message-feed.kbd.press

ARIA

These attributes are produced by connect.

Part	Attribute	Value
list	aria-label	translations.feed
list	role	'feed'
item	aria-label	undefined | itemLabel(item.index + 1, count ?? -1, item.role)
item	aria-labelledby	scope.partId('message-feed', item-label:${item.id}) | undefined
item	aria-posinset	item.index + 1
item	aria-setsize	props.count
item	role	'article'
separator	aria-hidden	'true'
pending-indicator	aria-hidden	'true'
scroll-to-end-trigger	aria-label	translations.scrollToBottomUnread(unreadCount) | translations.scrollToBottom
unread-count	aria-hidden	'true'
live-region	aria-atomic	'true'
live-region	aria-live	'polite'

Style reference

Skin

@xihan-ui/styles/message-feed.css is written against [data-scope="message-feed"][data-part="root"] part selectors; the published build uses the mount class .xh-scope-message-feed in place of data-scope (same specificity) and sits in the xihan.components layer. Put overrides in xihan.overrides; the part selectors work as usual.

Data attributes

Produced by connect; valueless attributes are omitted while their condition does not hold.

Part	Attribute	Value
root	data-size	props.size
root	data-state	props.status
list	data-instant	'' (present only while the condition holds)
item	data-role	item.role
item	data-streaming	'' (present only while the condition holds)
pending-indicator	data-state	props.status
scroll-to-end-trigger	data-pressed	'' (present only while the condition holds)
scroll-to-end-trigger	data-state	'hidden' | 'visible'
scroll-to-end-trigger	data-xh-action-control	''
scroll-to-end-trigger	data-xh-action-display	'always'
scroll-to-end-trigger	data-xh-action-profile	'floating'
scroll-to-end-trigger	data-xh-action-size	floatingSizeBelow(prop('size'))
scroll-to-end-trigger	data-xh-action-variant	'ghost'
scroll-to-end-trigger	data-xh-liquid	''
scroll-to-end-trigger	data-xh-material	'frosted'

CSS variables

The public override slots, generated from what the standalone skin actually consumes.

Variable	Part	CSS property	State	Default from
--xh-message-feed-gap	list	gap	default	--xh-_message-feed-gap
--xh-message-feed-icon-size	scroll-to-end-trigger	--xh-icon-size	default	--xh-_action-profile-glyph-size
--xh-message-feed-item-gap	item	gap	default	--xh-space-1
--xh-message-feed-item-radius	item	border-radius	default	--xh-shape-surface
--xh-message-feed-label-fg	item-label	color	default	--xh-fg-muted
--xh-message-feed-label-font-size	item-label	font-size	default	--xh-text-caption-size
--xh-message-feed-p	list pending-indicator	margin-block-end margin-inline-start padding	default	--xh-_message-feed-p
--xh-message-feed-pending-indicator-color	pending-indicator	background	default	--xh-fg-muted
--xh-message-feed-pending-indicator-radius	pending-indicator	border-radius	default	--xh-shape-circle
--xh-message-feed-pending-indicator-size	pending-indicator	block-size inline-size	default	--xh-space-2
--xh-message-feed-scroll-to-end-trigger-bg	scroll-to-end-trigger	--xh-ink-surface background-color	default disabled focus-visible xh-ink-surface	--xh-_material-bg --xh-_material-bg-focus
--xh-message-feed-scroll-to-end-trigger-bg-hover	scroll-to-end-trigger	background-color	disabled hover loading not([data-disabled]) not([data-loading])	--xh-_material-bg-hover
--xh-message-feed-scroll-to-end-trigger-border	scroll-to-end-trigger	border border-color	default disabled focus-visible hover is(:active, [data-pressed]) loading not([data-disabled]) not([data-loading]) pressed	--xh-_material-border
--xh-message-feed-scroll-to-end-trigger-fg	scroll-to-end-trigger	color	default disabled focus-visible hover is(:active, [data-pressed]) loading not([data-disabled]) not([data-loading]) pressed	--xh-_material-fg
--xh-message-feed-scroll-to-end-trigger-inset	scroll-to-end-trigger	inset-block-end inset-inline-end	default	--xh-space-4
--xh-message-feed-scroll-to-end-trigger-radius	scroll-to-end-trigger	border-radius	default	--xh-shape-circle
--xh-message-feed-scroll-to-end-trigger-shadow	scroll-to-end-trigger	box-shadow	default disabled focus-visible hover is(:active, [data-pressed]) is(:hover, [data-loading]) loading not([data-disabled]) not([data-loading]) pressed	--xh-_material-shadow
--xh-message-feed-scroll-to-end-trigger-size	scroll-to-end-trigger	block-size inline-size	default xh-action-profile=floating	--xh-_action-profile-visual-size
--xh-message-feed-separator-fg	separator	color	default	--xh-fg-subtle
--xh-message-feed-separator-font-size	separator	font-size	default	--xh-text-caption-size
--xh-message-feed-separator-gap	separator	gap	default	--xh-space-3
--xh-message-feed-separator-line	separator	border-block-start	default	--xh-border-subtle
--xh-message-feed-unread-count-bg	unread-count	background	default	--xh-bg-brand
--xh-message-feed-unread-count-fg	unread-count	color	default	--xh-fg-on-brand
--xh-message-feed-unread-count-font-size	unread-count	font-size	default	--xh-text-caption-size
--xh-message-feed-unread-count-px	unread-count	padding-inline	default	--xh-space-1
--xh-message-feed-unread-count-radius	unread-count	border-radius	default	--xh-shape-pill
--xh-message-feed-unread-count-size	unread-count	block-size line-height min-inline-size	default	--xh-space-4