Events & Hooks

Event system for reacting to pool changes.

on()

Registers an event handler.

pool.on(event: string, handler: Function): void

Parameters:

• event - Event name
• handler - Handler function

Available Events:

• add - Fired when an entry is added
• batchAdd - Fired when multiple entries are added
• get - Fired when an entry is retrieved
• set - Fired when an entry is updated
• remove - Fired when an entry is removed
• batchRemove - Fired when multiple entries are removed
• beforeSelect - Fired before query selection
• afterSelect - Fired after query selection

Example:

pool.on('add', (entry: PoolEntry<User>) => {
  console.log(`User ${entry.data.name} added`);
});

pool.on('get', (entry: PoolEntry<Proxy>) => {
  entry.meta.usedCount++;
  entry.meta.lastUsed = new Date();
});

off()

Unregisters an event handler.

pool.off(event: string, handler: Function): void

Parameters:

• event - Event name
• handler - Handler function to remove

Example:

const handler = (entry) => console.log(entry);
pool.on('add', handler);
pool.off('add', handler);

wrap()

Wraps a method with custom behavior.

pool.wrap<K extends keyof Pool<T>>(
  method: K,
  wrapper: (original: Function, ...args: any[]) => any
): void

Parameters:

• method - Method name to wrap
• wrapper - Wrapper function

Example:

// Add logging to the add method
pool.wrap('add', (original, data, meta) => {
  console.log(`Adding: ${data.name}`);
  const result = original(data, meta);
  console.log(`Added successfully`);
  return result;
});

pool.add({ id: '1', name: 'Alice' });
// Logs:
// Adding: Alice
// Added successfully