@xstate/[email protected]

Minor Changes

• #5200 0332a16a42fb372eb614df74ff4cb7f003c31fc8 Thanks @{! - Added selectors to @xstate/store that enable efficient state selection and subscription:

  • store.select(selector) function to create a "selector" entity where you can:
    • Get current value with .get()
    • Subscribe to changes with .subscribe(callback)
    • Only notify subscribers when selected value actually changes
    • Support custom equality functions for fine-grained control over updates via store.select(selector, equalityFn)

  const store = createStore({
    context: {
      position: { x: 0, y: 0 },
   name: 'John', age: 30 }
    },
    on: {
      positionUpdated: (
        context,
        event: { position: { x: number; y: number } }
      ) => ({
        ...context,
        position: event.position
      })
    }
  });
  
  const position = store.select((state) => state.context.position);
  
  position.get(); // { x: 0, y: 0 }
  
  position.subscribe((position) => {
    console.log(position);
  });
  
  store.trigger.positionUpdated({ x: 100, y: 200 });
  // Logs: { x: 100, y: 200 }