---
phase: 05-search
plan: 02
subsystem: search
tags: [filtering, text-highlighting, xss-prevention, pure-functions]

# Dependency graph
requires:
  - phase: 05-01
    provides: SearchFilters type and utility functions
  - phase: 04-01
    provides: Tags schema with case-insensitive matching
provides:
  - filterEntries utility for client-side entry filtering
  - highlightText utility for search result emphasis
affects: [05-03, search-integration]

# Tech tracking
tech-stack:
  added: []
  patterns: [pure-function-utilities, xss-safe-html-generation]

key-files:
  created:
    - src/lib/utils/filterEntries.ts
    - src/lib/utils/highlightText.ts
  modified: []

key-decisions:
  - "Case-insensitive matching for both text search and tag filtering"
  - "AND logic for multiple tag filters"
  - "HTML escaping before highlighting to prevent XSS"
  - "Bold styling without background for highlighted text"

patterns-established:
  - "Pure filter functions: Take data + criteria, return filtered data"
  - "XSS-safe HTML generation: Escape first, then modify"

# Metrics
duration: 1min
completed: 2026-01-31
---

# Phase 5 Plan 02: Filtering & Highlighting Utilities Summary

**Pure filter and highlight utilities with case-insensitive search, AND-logic tag filtering, and XSS-safe text highlighting**

## Performance

- **Duration:** 1 min
- **Started:** 2026-01-31T16:11:19Z
- **Completed:** 2026-01-31T16:12:57Z
- **Tasks:** 2
- **Files modified:** 2

## Accomplishments
- filterEntries utility filtering by query, tags, type, and date range
- highlightText utility with XSS protection via HTML escaping
- Case-insensitive text search with 2-character minimum trigger
- AND logic for tag filtering (entry must have ALL selected tags)

## Task Commits

Each task was committed atomically:

1. **Task 1: Create filterEntries utility function** - `8f544a9` (feat)
2. **Task 2: Create highlightText utility function** - `6dbe660` (feat)

## Files Created/Modified
- `src/lib/utils/filterEntries.ts` - Filters entries by SearchFilters criteria
- `src/lib/utils/highlightText.ts` - Wraps matching text in mark tags with XSS protection

## Decisions Made
- Case-insensitive matching for both text search and tag filtering (per 04-01 decision)
- AND logic for multiple tag filters (entry must have ALL selected tags)
- HTML escaping before regex replacement to prevent XSS
- Bold styling (font-bold) without background (bg-transparent) per CONTEXT.md

## Deviations from Plan

None - plan executed exactly as written.

## Issues Encountered
None

## User Setup Required

None - no external service configuration required.

## Next Phase Readiness
- Filter and highlight utilities ready for integration in 05-03
- SearchFilters type from 05-01 used correctly
- Both functions are pure and testable

---
*Phase: 05-search*
*Completed: 2026-01-31*