bbs-md/.planning/phases/04-bbs-polish-and-live-content/04-03-SUMMARY.md

phase, plan, subsystem, tags, requires, provides, affects, tech-stack, key-files, key-decisions, patterns-established, requirements-completed, duration, completed

phase	plan	subsystem	tags	requires	provides	affects	tech-stack	key-files	key-decisions	patterns-established	requirements-completed	duration	completed
04-bbs-polish-and-live-content	03	app	notify filesystem-watcher live-reload debounce mpsc rust event-loop	phase provides 04-01 notify = 6.1 in Cargo.toml phase provides 04-02 __directory__ sentinel, navigate_to_directory(), list_vault_files(), rewatch target for virtual page	FileWatcher pub struct with RecommendedWatcher, mpsc Receiver, rewatch() method file_watcher and pending_reload_at fields on App struct reload_current_document() preserving scroll position and link selection rewatch_for_current_page() re-pointing watcher on every navigation event try_recv() drain loop in event loop for non-blocking filesystem event polling 300ms debounce timer firing reload after last relevant event FileWatcher initialized in main.rs with non-fatal failure handling		added patterns notify 6.1 RecommendedWatcher with mpsc channel — already in Cargo.toml from Plan 01 FileWatcher wraps RecommendedWatcher + Receiver in a struct with a rewatch() helper Drain loop pattern: loop { match rx.try_recv() { ... Err(Empty) => break } } drains all queued events per poll iteration Debounce pattern: pending_reload_at = Some(Instant::now()) on each event, reload fires 300ms after last event Directory watch pattern: watch parent dir, not the file itself — survives atomic saves (vim/neovim rename-over) Non-fatal watcher creation: watcher failure prints warning, app runs without live reload (None passed to App)	created modified src/app.rs — FileWatcher struct, file_watcher/pending_reload_at fields, App::new() new param, reload_current_document(), rewatch_for_current_page(), try_recv drain loop + debounce in run_event_loop(), rewatch calls in all navigate_* methods src/main.rs — FileWatcher creation before App::new(), non-fatal error handling, updated App::new() call with file_watcher arg	Watch parent directory of current file (not the file itself) — survives atomic saves where editors write to temp file then rename Drain loop pattern: loop { try_recv() ... break on Empty/Disconnected } — processes all queued events per poll so rapid saves do not queue lag 300ms debounce: pending_reload_at reset on each event — reload fires only after 300ms of silence from last event File watcher initialized in main.rs before App::new() — avoids self-referential borrowing, keeps App::new() pure Non-fatal watcher failure: eprintln warning only, None passed to App — app fully functional without live reload	notify mpsc pattern: RecommendedWatcher::new(tx, Config::default()) + Receiver<notify::Result<notify::Event>> stored together Debounce in event loop: check pending_reload_at after polling phase, not in key handler	LIVE-01	7min	2026-03-01

Phase 4 Plan 03: Live Filesystem Watching Summary

FileWatcher struct using notify 6.1 mpsc pattern wired into App event loop with 300ms debounce, parent-directory watching, and non-fatal startup error handling

Performance

• Duration: 7 min
• Started: 2026-03-01T10:20:21Z
• Completed: 2026-03-01T10:27:00Z
• Tasks: 2
• Files modified: 2

Accomplishments

• FileWatcher pub struct created in src/app.rs — wraps RecommendedWatcher, Receiver<notify::Result<notify::Event>>, and watched_dir: PathBuf with a rewatch() helper that safely unwatches the old directory before watching the new one
• file_watcher: Option<FileWatcher> and pending_reload_at: Option<Instant> fields added to App struct
• App::new() signature updated with file_watcher: Option<FileWatcher> as seventh parameter
• reload_current_document() method added — handles both the __directory__ virtual page (calls list_vault_files() + build_directory_lines()) and real documents (re-reads from disk, re-renders markdown with splash prepend for index.md), preserves scroll offset and link selection after reload
• rewatch_for_current_page() method added — re-points watcher to parent directory of current file, or vault root for __directory__; called at the end of all four navigation methods
• try_recv() drain loop added to run_event_loop() after event polling — non-blocking, drains all queued events per iteration, filters events by filename match (or .md extension for directory pages)
• 300ms debounce timer integrated — pending_reload_at reset to Some(Instant::now()) on each relevant event, reload fires only after 300ms of silence
• FileWatcher::new() called in main.rs before App::new(), non-fatal: watcher creation failure prints a warning and passes None to App so the app runs normally without live reload

Task Commits

Each task was committed atomically:

1. Task 1: FileWatcher struct and event loop integration - a44c9cc (feat)
2. Task 2: Initialize FileWatcher in main.rs and wire App constructor - f3133dd (feat)

Files Created/Modified

• src/app.rs - FileWatcher struct; file_watcher/pending_reload_at fields on App; App::new() new param; reload_current_document(); rewatch_for_current_page(); try_recv drain loop and debounce in run_event_loop(); rewatch_for_current_page() calls in all navigate_* methods
• src/main.rs - FileWatcher creation in step 3c; non-fatal error handling with eprintln!; updated App::new() call with file_watcher argument

Decisions Made

• Watch parent directory, not the file itself — survives atomic saves (vim/neovim write to a temp file then rename it over the target; inotify RENAME events on the directory catch this correctly)
• Drain loop per poll iteration — ensures all queued events from a rapid burst are consumed; debounce collapses the burst into a single reload after 300ms of silence
• File_watcher initialized in main.rs before App::new() — avoids self-referential ownership issues and keeps the constructor pure
• Non-fatal failure path — watcher depends on OS filesystem notification support; platforms or permission configurations where it fails should not prevent the BBS from running

Deviations from Plan

None - plan executed exactly as written. The notify crate Config type required aliasing to NotifyConfig to avoid shadowing the existing crate::config::Config import, which is a natural Rust naming convention applied automatically.

Issues Encountered

None. The notify 6.1 API was exactly as specified in the plan: RecommendedWatcher::new(tx, Config::default()) and mpsc::channel(). Build passed on first attempt. The two pre-existing clippy warnings (is_within_vault, init_logging) and the two pre-existing renderer.rs style suggestions are out of scope for this plan.

User Setup Required

None - live reload is automatic. File changes to the currently displayed .md file are detected within ~800ms (300ms debounce + up to 500ms from two 250ms poll iterations). No configuration needed.

Phase 4 Complete

This is the final plan of Phase 4 and the final plan of the project. All requirements have been met:

• BBS-01: Splash screen (splash.txt ANSI art) prepended to index.md (Plan 01)
• BBS-02: File metadata (mtime, size) in status bar (Plan 01)
• LIVE-02: Virtual [[Directory]] page with tree view and Tab-cycling (Plan 02)
• LIVE-01: Live filesystem watching with auto-refresh and scroll preservation (Plan 03)

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Phase: 04-bbs-polish-and-live-content Completed: 2026-03-01