Phoenix LiveView Essentials FAQs

Question 1

Why should I check connected?(socket) in mount/3?

Accepted Answer

Side effects like PubSub subscriptions or timers only work over a WebSocket connection. Checking for connectivity prevents these operations from failing during the initial static render.

Question 2

Why avoid direct database queries in LiveView modules?

Accepted Answer

Following Phoenix best practices, data access should be encapsulated in Context modules. This keeps your LiveView focused on UI logic and makes your application easier to test and maintain.

Question 3

What is two-phase rendering in Phoenix LiveView?

Accepted Answer

LiveView renders twice: first as a static HTML response for fast initial loading (disconnected), and second once the WebSocket is established (connected). This skill ensures you initialize assigns correctly to support both phases.

Question 4

How do I prevent KeyErrors in my HEEX templates?

Accepted Answer

This skill mandates initializing all assigns in the mount/3 callback. By ensuring every key accessed in a template exists from the start, you avoid runtime errors during the initial render.

Question 5

When should I use LiveView Streams over standard assigns?

Accepted Answer

Use Streams for large collections of data that need to be updated or appended. Streams are more memory-efficient because they don't keep the entire list in the socket state.

Phoenix LiveView Essentials

Phoenix LiveView Essentials

主要功能

使用场景

主要功能

使用场景