Phoenix LiveView Patterns

Expert guidance for building real-time, interactive web applications with Phoenix LiveView.

Lifecycle & State

• Keep mount/3 minimal — assign only what's needed for initial render
• Use handle_params/3 for URL-driven state, not mount/3
• Prefer assign_new/3 over assign/3 when value may already exist
• Use assign_async/3 and start_async/3 for expensive operations
• Never block mount/3 with slow database queries or API calls

# ✅ Good: Minimal mount, async loading
def mount(_params, _session, socket) do
  {:ok, assign(socket, page_title: "Dashboard", loading: true)}
end

def handle_params(%{"id" => id}, _uri, socket) do