Proposal: public cross-session conversation view navigation for Web plugins

[Nirvana-Jie]

Summary

A conversation.view plugin can select another durable session through ctx.sessions.open(sessionId), but it cannot also select the target conversation view through a supported public API. The active view belongs to a private, per-session ui-conversation store.

This becomes visible in a session-lineage plugin: selecting a historical branch and clicking Open session changes the durable session, but the target can remain on the Session Tree tab instead of returning to Chat.

Reproduction

1. Register a session-scoped conversation.view entry, for example session-tree.
2. Open Session A and select that view.
3. From the plugin, choose Session B and call ctx.sessions.open(sessionB).
4. Session B becomes current, but its persisted active view is unchanged. If Session B last displayed session-tree, the user remains in the plugin rather than arriving in Chat.

An earlier workaround attempted to call conversation.showChat() on the target scope. That method is not part of IConversation, so the runtime correctly fails with conversation.showChat is not a function. DOM clicks, localStorage, or reaching into the private store would make the plugin depend on implementation details and should not be required.

Proposed API

Add one explicit navigation method to the outward conversation service:

interface IConversation {
  openSession(sessionId: SessionId, viewId: string): void
}

The plugin call then becomes:

ctx.conversation.openSession(id, 'chat')

The operation should be owned by ui-conversation because it is the only package that owns both the public Sessions navigation dependency and the private per-session view writers.

Prepared implementation

I prepared and locally validated a minimal implementation with these semantics:

• Keep a generation-safe map from rendered Session IDs to their actions.setView writers.
• If the target Session is already rendered, select the requested view before calling sessions.open.
• If the target is not rendered yet, retain one latest-wins pending { sessionId, viewId } request and consume it when that Session mounts.
• Clear the pending request if sessions.open throws.
• Remove only the matching writer generation during unmount, so a stale disposer cannot erase a newer binding.
• Keep the store private; no plugin receives the store handle, DOM selectors, or persistence details.

The consumer-side change is available in dsh-session-tree, specifically fix(client): use supported session navigation.

Validation

The prepared Harness change passes 40 focused ui-conversation tests covering service orchestration, slot injection, active targets, targets that mount after navigation, failure cleanup, and generation-safe teardown.

The plugin passes 22 Vitest tests plus coverage, TypeScript, lint, build, and publint checks.

A real DSH Web verification exercised this path:

1. Open Session A.
2. Enter Session Tree.
3. Select Session B.
4. Click Open session.
5. Confirm that the page title changes to Session B and the Chat tab has aria-selected="true".

The clean browser run completed with no console errors or warnings.

Question for maintainers

Does IConversation.openSession(sessionId, viewId) fit the intended plugin API, or would maintainers prefer a more general navigation capability? I can publish the prepared Harness commit from a fork once the API direction is confirmed.

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中文摘要

目前 Web 插件可以通过 sessions.open 切换持久化会话，但无法通过公开 API 同时指定目标会话的活动视图；视图状态属于 ui-conversation 的私有会话级 store。因此会话树插件点击“打开会话”后，可能已经切换到目标会话，却仍停留在“会话树”而不是“对话”。建议由 ui-conversation 提供 conversation.openSession(sessionId, viewId)，原子地完成会话与视图切换，并处理目标会话尚未挂载、打开失败和组件卸载竞争。实现与真实端到端验证已经完成，确认方向后可以从 fork 提交 PR。