What advantage does this delegation pattern provide?
class DelegateManager {
constructor(root) {
this.root = root;
this.handlers = new Map();
}
on(eventType, selector, handler) {
if (!this.handlers.has(eventType)) {
this.handlers.set(eventType, new Map());
this.root.addEventListener(eventType, this.handleEvent.bind(this));
}
this.handlers.get(eventType).set(selector, handler);
}
handleEvent(e) {
const handlers = this.handlers.get(e.type);
for (const [selector, handler] of handlers) {
const target = e.target.closest(selector);
if (target && this.root.contains(target)) {
handler.call(target, e);
}
}
}
}
This DelegateManager class provides centralized management of event delegation through a clean API. Benefits include: 1) Reduces boilerplate by handling common delegation patterns, 2) Maintains a single listener per event type regardless of how many selectors are registered, 3) Provides a structured way to add and remove delegated handlers, 4) Encapsulates delegation mechanics, 5) Supports multiple event types and selectors efficiently, 6) Manages handler context automatically. This pattern is particularly useful in large applications where multiple components need delegation handling.