jedmund-svelte/prd/PRD-auto-save-functionality.md

Product Requirements Document: Auto-Save Functionality

Executive Summary

Implement an intelligent auto-save system for all admin forms and editors to prevent data loss and improve the content creation experience.

Problem Statement

Currently, users must manually save their work in the admin interface, which can lead to:

• Data loss if the browser crashes or connection is interrupted
• Anxiety about losing work during long editing sessions
• Inefficient workflow with frequent manual saves
• No recovery mechanism for unsaved changes

Goals & Success Metrics

Primary Goals

1. Prevent data loss during content creation
2. Provide seamless, unobtrusive saving experience
3. Enable recovery from unexpected interruptions
4. Maintain data consistency and integrity

Success Metrics

• 0% data loss from browser crashes or network issues
• <3 second save latency for typical content
• 95% of saves complete without user intervention
• User satisfaction with editing experience improvement

User Stories

As a content creator

• I want my work to be automatically saved so I don't lose progress
• I want to see clear feedback about save status
• I want to recover my work if something goes wrong
• I want control over when auto-save is active

As a site administrator

• I want to ensure data integrity across all saves
• I want to minimize server load from frequent saves
• I want to track save patterns for optimization

Functional Requirements

Core Auto-Save System

1. Smart Debouncing

• Content changes: 2-second delay after user stops typing
• Metadata changes: Immediate save for critical fields
• Navigation events: Immediate save before leaving page
• Keyboard shortcut: Cmd/Ctrl+S for manual save

2. Save States & Feedback

• Idle: No pending changes
• Saving: Active save in progress with spinner
• Saved: Confirmation with timestamp
• Error: Clear error message with retry option
• Conflict: Detection and resolution UI

3. Data Persistence

• Server-first: Primary storage in database
• Local backup: IndexedDB for offline/recovery
• Conflict detection: Version tracking with timestamps
• Partial saves: Only send changed fields

Visual Design

Status Indicator

States:
- Idle: No indicator (clean UI)
- Saving: "Saving..." with subtle spinner
- Saved: "All changes saved" (fades after 2s)
- Error: Red indicator with retry button
- Offline: "Working offline" badge

Positioning

• Fixed position in editor header
• Non-intrusive, doesn't shift content
• Responsive to different screen sizes
• Accessible color contrast

API Design

New Endpoints

// Auto-save endpoint
POST /api/posts/[id]/autosave
Body: {
  content?: JSONContent,
  title?: string,
  metadata?: object,
  lastModified: timestamp
}
Response: {
  success: boolean,
  lastModified: timestamp,
  conflict?: {
    serverVersion: object,
    serverModified: timestamp
  }
}

// Recovery endpoint  
GET /api/posts/[id]/recover
Response: {
  localDraft?: object,
  serverVersion: object,
  timestamps: {
    local?: timestamp,
    server: timestamp
  }
}

Integration Points

Form Components to Update

1. EssayForm.svelte - Blog posts and essays
2. ProjectForm.svelte - Project case studies
3. AlbumForm.svelte - Album descriptions
4. SimplePostForm.svelte - Simple text posts
5. PhotoPostForm.svelte - Photo posts with captions

Composer Integration

• Hook into TipTap editor's onUpdate event
• Track content changes separately from metadata
• Handle rich media embeds appropriately

Technical Requirements

Frontend Architecture

Auto-Save Hook (useAutoSave.svelte.ts)

class AutoSave {
  private state = $state<'idle' | 'saving' | 'saved' | 'error'>('idle')
  private lastSaved = $state<Date | null>(null)
  private saveTimer: NodeJS.Timeout | null = null
  private saveQueue: Set<string> = new Set()
  
  constructor(options: AutoSaveOptions) {
    // Initialize with endpoint, auth, debounce settings
  }
  
  track(field: string, value: any): void
  save(immediate?: boolean): Promise<void>
  recover(): Promise<RecoveryData>
  reset(): void
}

Svelte 5 Integration

• Use $state rune for reactive state
• Use $effect for side effects and cleanup
• Use $derived for computed values
• Maintain compatibility with existing stores

Backend Requirements

Database Schema Updates

-- Add version tracking
ALTER TABLE posts ADD COLUMN version INTEGER DEFAULT 1;
ALTER TABLE posts ADD COLUMN last_auto_save TIMESTAMP;

-- Auto-save drafts table
CREATE TABLE auto_save_drafts (
  id SERIAL PRIMARY KEY,
  entity_type VARCHAR(50),
  entity_id INTEGER,
  user_id INTEGER,
  content JSONB,
  created_at TIMESTAMP DEFAULT NOW()
);

Performance Optimizations

• Implement request coalescing for rapid changes
• Use database transactions for consistency
• Add Redis caching for conflict detection
• Implement rate limiting per user

Security Considerations

• Validate user ownership before auto-save
• Sanitize content to prevent XSS
• Rate limit to prevent abuse
• Encrypt local storage data
• Audit trail for all saves

Non-Functional Requirements

Performance

• Save latency <500ms for text content
• <2MB memory overhead per form
• Debounce efficiency >90% reduction in requests
• Support 100+ concurrent editors

Reliability

• 99.9% save success rate
• Graceful degradation on network issues
• Automatic retry with exponential backoff
• Data recovery from last 24 hours

Usability

• Zero configuration for basic use
• Clear, non-technical error messages
• Intuitive conflict resolution
• Keyboard accessible

Compatibility

• Chrome 90+, Firefox 88+, Safari 14+
• Mobile responsive
• Works with screen readers
• Progressive enhancement

Implementation Plan

Phase 1: Core Infrastructure (Week 1-2)

• Create useAutoSave hook
• Implement debouncing logic
• Add basic status component
• Create auto-save API endpoint

Phase 2: Form Integration (Week 2-3)

• Integrate with EssayForm
• Integrate with ProjectForm
• Add keyboard shortcuts
• Implement local storage backup

Phase 3: Advanced Features (Week 3-4)

• Conflict detection and resolution
• Offline support with service worker
• Recovery interface
• Performance monitoring

Phase 4: Polish & Testing (Week 4-5)

• UI/UX refinements
• Comprehensive testing
• Documentation
• Performance optimization

Testing Strategy

Unit Tests

• Debounce logic validation
• State management correctness
• API error handling
• Local storage operations

Integration Tests

• Form component integration
• API endpoint validation
• Conflict resolution flow
• Recovery scenarios

E2E Tests

• Complete save flow
• Network interruption handling
• Multi-tab scenarios
• Mobile experience

Performance Tests

• Load testing with concurrent users
• Memory leak detection
• Network bandwidth usage
• Database query optimization

Rollout Strategy

1. Beta Testing: Deploy to staging with select users
2. Gradual Rollout: Enable for 10% → 50% → 100% of forms
3. Monitoring: Track save success rates and user feedback
4. Iteration: Refine based on real-world usage

Future Enhancements

Version 2.0

• Real-time collaboration indicators
• Revision history with diff view
• Auto-save templates and drafts
• AI-powered content suggestions

Version 3.0

• Multi-device sync
• Offline-first architecture
• Advanced merge conflict resolution
• Team collaboration features

Risks & Mitigations

Risk	Impact	Mitigation
Data corruption	High	Implement checksums and validation
Performance degradation	Medium	Rate limiting and request batching
User confusion	Low	Clear UI feedback and documentation
Storage limits	Low	Implement cleanup and quotas

Dependencies

External Libraries

• None required (uses native Svelte/SvelteKit features)

Internal Systems

• Existing authentication system
• Toast notification system
• TipTap editor integration
• Prisma database client

Acceptance Criteria

• Auto-save activates within 2 seconds of changes
• Visual feedback appears for all save states
• Manual save button remains functional
• Recovery works after browser crash
• No data loss in normal operation
• Performance metrics meet targets
• Accessibility standards met
• Documentation complete

Appendix

Competitive Analysis

• Notion: Instant save with "Saving..." indicator
• Google Docs: Real-time with conflict resolution
• WordPress: Auto-save drafts every 60 seconds
• Medium: Continuous save with version history

User Research Insights

• Users expect auto-save in modern editors
• Visual feedback reduces anxiety
• Recovery options increase trust
• Performance is critical for user satisfaction

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Document Version: 1.0
Last Updated: 2025-01-30
Author: System Architecture Team
Status: Ready for Implementation