triqura-ecd/docs/swift/implementation-e5-s3-error-states.md

Epic 5.S3 Implementation: Error States

Story: E5.S3 - Error states Date: 2025-12-27 Status: ✅ Complete Story Points: 2 SP

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🎯 Objective

Add user-friendly error states to agenda functionality with fallback links to /epd/agenda and proper error messaging in Dutch.

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📝 Implementation Summary

New Component Created

components/swift/artifacts/blocks/agenda-error-state.tsx

Created two reusable error components for consistent error handling across all agenda views:

1. AgendaErrorState - Full-page error state with retry button
2. AgendaErrorAlert - Inline error alert for forms

Updated Components

components/swift/artifacts/blocks/agenda-create-form.tsx

• Replaced basic error display with AgendaErrorAlert
• Added fallback link to full agenda
• Added dismiss functionality

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🔑 Key Features

1. User-Friendly Error Messages

The getUserFriendlyMessage() function maps technical errors to Dutch user-facing messages:

Error Type	Technical	User Message
Auth (401)	"401 Unauthorized"	"Je sessie is verlopen. Log opnieuw in."
Not Found (404)	"404 Not Found"	"De gevraagde afspraak kon niet worden gevonden."
Forbidden (403)	"403 Forbidden"	"Je hebt geen toegang tot deze afspraak."
Server (500)	"500 Internal Server Error"	"Er ging iets mis op de server. Probeer het opnieuw."
Network	"Failed to fetch"	"Geen internetverbinding. Controleer je netwerkverbinding."
Timeout	"Request timeout"	"De aanvraag duurde te lang. Probeer het opnieuw."

2. Context-Aware Messages

Different default messages based on operation context:

context: 'query' → "Er ging iets mis bij het ophalen van je afspraken."
context: 'create' → "Er ging iets mis bij het aanmaken van de afspraak."
context: 'cancel' → "Er ging iets mis bij het annuleren van de afspraak."
context: 'reschedule' → "Er ging iets mis bij het verzetten van de afspraak."

3. Fallback Link to Full Agenda

All error states include a prominent link to /epd/agenda:

<Button onClick={() => window.location.href = '/epd/agenda'}>
  <ExternalLink className="h-4 w-4" />
  Open volledige agenda
</Button>

4. Automatic Auth Redirect

Auth errors (401) automatically redirect to /login:

if (isAuthError) {
  window.location.href = '/login';
  return null;
}

5. Retry Functionality

Optional retry button for recoverable errors:

<AgendaErrorState
  error={error}
  onRetry={() => fetchAppointments()}
  showFallbackLink={true}
  context="query"
/>

6. Dev-Only Technical Details

In development mode, shows collapsible technical details:

{process.env.NODE_ENV === 'development' && (
  <details>
    <summary>Technische details (dev only)</summary>
    <pre>{error.stack}</pre>
  </details>
)}

---

📐 Component API

AgendaErrorState (Full-Page Error)

interface AgendaErrorStateProps {
  error: string | Error;           // Error to display
  onRetry?: () => void;             // Optional retry function
  showFallbackLink?: boolean;       // Show link to /epd/agenda (default: true)
  context?: 'query' | 'create' | 'cancel' | 'reschedule';
}

Usage Example:

<AgendaErrorState
  error="Failed to fetch appointments"
  onRetry={() => refetch()}
  context="query"
/>

AgendaErrorAlert (Inline Alert)

interface AgendaErrorAlertProps {
  error: string | Error;           // Error to display
  onDismiss?: () => void;          // Optional dismiss function
  showFallbackLink?: boolean;      // Show link to /epd/agenda (default: false)
}

Usage Example:

{error && (
  <AgendaErrorAlert
    error={error}
    onDismiss={() => setError(null)}
    showFallbackLink={true}
  />
)}

---

✅ Acceptance Criteria

Criterion	Status	Implementation
User-friendly error messages	✅	getUserFriendlyMessage() function
Dutch language errors	✅	All messages in Dutch
Fallback link to /epd/agenda	✅	"Open volledige agenda" button
Auth error redirect	✅	Automatic redirect to /login
Retry functionality	✅	Optional onRetry prop
Context-aware messages	✅	Different messages per operation type
Network error handling	✅	"Geen internetverbinding" message
Server error handling	✅	"Er ging iets mis op de server" message
TypeScript type safety	✅	Full type definitions
Consistent styling	✅	Matches existing UI patterns

---

🎨 UI Design

Full-Page Error State

┌─────────────────────────────────────┐
│                                     │
│         🔴 (AlertCircle Icon)       │
│                                     │
│      Er ging iets mis               │
│                                     │
│  Er ging iets mis bij het           │
│  ophalen van je afspraken.          │
│                                     │
│  ┌──────────────┐ ┌──────────────┐  │
│  │ 🔄 Probeer   │ │ 🔗 Open      │  │
│  │   opnieuw    │ │   volledige  │  │
│  └──────────────┘ │   agenda     │  │
│                   └──────────────┘  │
│                                     │
└─────────────────────────────────────┘

Inline Error Alert

┌─────────────────────────────────────┐
│ ⚠️  Er ging iets mis bij het        │
│     aanmaken van de afspraak.       │
│     Open volledige agenda →     [×] │
└─────────────────────────────────────┘

---

🧪 Testing Scenarios

Scenario 1: Network Error

Trigger: Disconnect internet, try to create appointment Expected:

• Message: "Geen internetverbinding. Controleer je netwerkverbinding."
• Retry button enabled
• Fallback link visible

Scenario 2: Auth Error (401)

Trigger: Expired session token Expected:

• Automatic redirect to /login
• No error component shown

Scenario 3: Server Error (500)

Trigger: Backend returns 500 Expected:

• Message: "Er ging iets mis op de server. Probeer het opnieuw."
• Retry button enabled
• Fallback link visible

Scenario 4: Not Found (404)

Trigger: Try to cancel non-existent appointment Expected:

• Message: "De gevraagde afspraak kon niet worden gevonden."
• Fallback link visible

Scenario 5: Validation Error

Trigger: Submit form with invalid data Expected:

• Inline alert with specific validation message
• Fallback link visible
• Dismiss button works

Scenario 6: Retry Success

Trigger: Network error → reconnect → click retry Expected:

• Retry function called
• Error cleared on success
• Content loads normally

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💡 Design Decisions

Why Two Components?

1. AgendaErrorState: For full-page failures (query, list loading)
2. AgendaErrorAlert: For form-level errors (create, cancel, reschedule)

Different UI patterns for different contexts.

Why Auto-Redirect for Auth Errors?

Auth errors (401) are not user-recoverable in the UI. User must log in again, so immediate redirect provides better UX than showing an error message.

Why Show Fallback Link?

If Swift fails, users can always fall back to the classic agenda UI at /epd/agenda. This provides a safety net and reduces frustration.

Why Context Parameter?

Different operations have different error messages. Context makes messages more specific and actionable:

• Query failure → "bij het ophalen"
• Create failure → "bij het aanmaken"
• etc.

Why Dev-Only Technical Details?

Technical stack traces are only useful for developers debugging issues. Production users should see user-friendly messages only.

---

🚀 Error Handling Best Practices

1. Always Use getUserFriendlyMessage()

// ❌ Bad - Technical error exposed to user
setError(error.message);

// ✅ Good - User-friendly Dutch message
const friendlyMessage = getUserFriendlyMessage(error, 'create');
setError(friendlyMessage);

2. Provide Context

// ❌ Bad - Generic error
<AgendaErrorState error={error} />

// ✅ Good - Context-specific error
<AgendaErrorState error={error} context="query" />

3. Offer Retry When Possible

// ❌ Bad - No recovery path
<AgendaErrorState error={error} />

// ✅ Good - User can retry
<AgendaErrorState
  error={error}
  onRetry={() => refetchAppointments()}
/>

4. Use Inline Alerts for Forms

// ❌ Bad - Full-page error for form validation
<AgendaErrorState error="Patient required" />

// ✅ Good - Inline alert in form
<AgendaErrorAlert
  error="Selecteer a.u.b. een patiënt."
  onDismiss={() => setError(null)}
/>

---

📊 Error Message Coverage

Covered error types:

• ✅ Authentication (401)
• ✅ Authorization (403)
• ✅ Not Found (404)
• ✅ Server Error (500)
• ✅ Network/Offline
• ✅ Timeout
• ✅ Validation
• ✅ Generic/Unknown

All with Dutch user-friendly messages.

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📁 Files Modified/Created

✅ components/swift/artifacts/blocks/agenda-error-state.tsx (NEW - 225 lines)
   ├── AgendaErrorState component
   ├── AgendaErrorAlert component
   └── getUserFriendlyMessage() utility

✅ components/swift/artifacts/blocks/agenda-create-form.tsx (UPDATED)
   └── Replaced basic error with AgendaErrorAlert

✅ docs/swift/bouwplan-swift-agenda-planning.md (UPDATED)
   └── E5.S3 → Done, Epic 5 → Done

✅ docs/swift/implementation-e5-s3-error-states.md (NEW)
   └── This documentation

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🎯 Impact

Before E5.S3

• ❌ Technical error messages exposed to users
• ❌ No fallback when errors occur
• ❌ No retry functionality
• ❌ Inconsistent error handling

After E5.S3

• ✅ User-friendly Dutch error messages
• ✅ Always provide fallback link to full agenda
• ✅ Retry button for recoverable errors
• ✅ Consistent error handling across all views
• ✅ Auto-redirect for auth errors
• ✅ Context-aware messaging

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🚀 Next Steps

Epic 6 - QA & Docs

• E6.S1: Manual test checklist (20 scenarios from build plan)
• E6.S2: Docs update (bouwplan + release note)
• E6.S3: Regression checks (Swift + klassieke agenda)

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Implementation Status: ✅ Complete Epic 5 Status: ✅ Complete (All 3 stories done) Ready for: Epic 6 (QA & Documentation)