LWCAdvancedplatform-eventsemp-apireal-time
Implement real-time updates with Platform Events in LWC
Real World Scenario
Operations dashboard LWC must refresh case counts when high-priority cases created without polling every 30 seconds.
Expected Answer
• empApi subscribe to channel in connectedCallback
• Unsubscribe in disconnectedCallback preventing memory leaks
• Filter events client-side matching user territory or queue
• Merge event payload into local state immutably triggering re-render
• Fallback polling when empApi connection fails with user notice
• Replay extension for missed events on reconnect advanced scenarios
• Governor-safe server publish from trigger not from LWC directly
Follow-Up Questions & Answers
Click to expand — each follow-up includes a direct, interview-ready answer
Direct answer: empApi subscribe to channel in connectedCallback Also consider: Unsubscribe in disconnectedCallback preventing memory leaks In practice: Filter events client-side matching user territory or queue Optimize for scale and operational observability.
Architect Perspective
Real-time LWC is subscriber only—architect event schema and publish rules server-side.