Add onStop callback to useStream hook enabling developers to customize
UI behavior when streams are stopped. This is especially useful for
UI messages with loading states that need to show "stopped" status
instead of remaining in infinite loading state.
The callback provides the same mutate function as onCustomEvent for
immediate local state updates, while users can optionally update
server thread state using the threads client.
Example usage:
```typescript
const stream = useStream({
assistantId: "my-assistant",
onStop: async ({ mutate }) => {
// Immediate UI update - stop loading components
mutate((prev) => ({
...prev,
ui: prev.ui?.map(component =>
component.props?.isLoading
? {
...component,
props: {
...component.props,
isLoading: false,
isStopped: true
}
}
: component
)
}));
// Optional server thread state update
if (stream.threadId) {
await stream.client.threads.updateState(stream.threadId, {
values: {
ui: prev.ui // persist stopped state to server
}
});
}
}
});
```
This is especially useful for cases where gen UI components have loading states,
where we don't want the loading state to persist on cancellation.
- Convert BytesLineDecoder and SSEDecoder from classes extending TransformStream to factory functions
- Fixes tree shaking failures that prevented build completion
- Maintains identical API functionality, just removes 'new' keyword usage
- All tests continue to pass
Resolves tree shaking side effect detection issues with TransformStream extension
- Document initialValues for cached thread display
- Document newThreadId for optimistic thread creation
- Add comprehensive test coverage for both features
github-actions[bot]