What are ngrx selectors and how do I use them?

What are ngrx selectors and how do I use them?

NgRx selectors are pure functions used to select slices of state from the store in Angular applications. They help in optimizing performance by memoizing the results.

Can you give me an example of how to create a selector?

Sure! You can create a selector using the createSelector function. For example:

import { createSelector } from '@ngrx/store';

const selectFeature = (state) => state.feature;

export const selectItems = createSelector(
  selectFeature,
  (featureState) => featureState.items
);

How do I use this selector in a component?

In your component, you can use the Store service to select the data:

import { Store } from '@ngrx/store';
import { selectItems } from './selectors';

constructor(private store: Store) {}

ngOnInit() {
  this.store.select(selectItems).subscribe(items => {
    console.log(items);
  });
}

What are the benefits of using selectors?

Selectors provide better performance through memoization, improve code readability, and help in maintaining a clean separation of concerns.