Announcer
Headless Announcer; covers ARIA live regions, coalesced announcement queues.
|
|
| Package |
@vizejs/ui/announcer |
| Maturity |
stable |
| Own the source |
vize lib pull announcer |
| Requires |
context, live-region |
| Aliases |
announcement queue, status announcer, busy announcements |
| Covers |
ARIA live regions, coalesced announcement queues |
Usage
import { AnnouncerProvider } from "@vizejs/ui/announcer";
Or copy the source into your project with vize lib pull announcer (see Source Distribution).
API
AnnouncerProvider
Source: src/families/accessibility/announcer/announcer-provider.vue
Props
| Prop |
Type |
Default |
Description |
politeness |
AnnouncerPoliteness |
"polite" |
Default urgency for announcements that do not name one. |
atomic |
boolean |
true |
Whether assistive technology should present a whole channel on each update. |
Slots
| Slot |
Slot props |
Description |
default |
{ readonly announcer: AnnouncerController } |
Subtree served by this announcer. Receives the owning controller. |
Exposed
| Member |
Type |
Description |
announcer |
— |
|
isOwner |
— |
|
announce |
— |
|
clear |
— |
|
Behavior
Normative state × input → outcome table for announcer-provider.vue and the
announcement queue (@vizejs/ui/announcer). Every row is proven by the named
test in src/families/accessibility/announcer/announcer.test.ts or
src/families/accessibility/announcer/announcer-ssr.test.ts; compile-only
assertions live in src/families/accessibility/announcer/announcer.types.test-d.ts.
| # |
State |
Input |
Outcome |
Proven by |
| N1 |
idle |
render provider |
one empty polite and one empty assertive region |
renders one polite and one assertive region |
| N2 |
idle |
announce sequence |
messages flush in order, one channel tick each |
queues announcements sequentially |
| N3 |
queued |
assertive announce |
assertive text precedes queued polite text |
flushes assertive announcements before polite ones |
| N4 |
queued |
identical announce |
duplicate pending text on a channel is dropped |
deduplicates identical pending announcements |
| N5 |
queued |
keyed announce |
a pending message with the same key is replaced |
coalesces keyed announcements |
| N6 |
busy |
update then end |
only the latest progress and the outcome are heard |
announces busy work without flooding |
| N7 |
busy ended |
update |
throws a stable busy diagnostic |
rejects progress after a busy announcement ends |
| N8 |
nested |
render provider in provider |
inner provider delegates; no duplicate regions |
nested providers reuse the owner's regions |
| N9 |
nested |
descendant announce |
text surfaces in the owning provider's region |
nested providers reuse the owner's regions |
| N10 |
queued |
clear |
pending queue drops and both channels empty |
clears pending announcements and both channels |
| N11 |
any |
dispose, then any call |
throws a stable disposed diagnostic |
rejects use after dispose |
| N12 |
no scope |
useAnnouncer |
throws a stable setup diagnostic |
rejects composable use outside an effect scope |
| N13 |
SSR |
render nested + setup announce |
byte-identical markup, single empty region pair |
SSR test |
| N14 |
public types |
invalid politeness |
compilation rejects misuse |
src/families/accessibility/announcer/announcer.types.test-d.ts |
Vize