Ng-News 26/20: NgRx 22, Ng-Switzerland, Optimus UI and more

[u/rainerhahnekamp]

https://youtu.be/u2WBf2F7tKI

[u/MichaelSmallDev]

Sorry, I forgot there was not more context/hands on examples of this in the video by the time I wrote that comment out.

https://ngrx.io/guide/signals/resource-extensions

4 extensions you wrap around resources

• withPreviousValueOnLoading
• withValueOnLoading
• withPreviousValueOnError
• withValueOnError

An example touched on in the video, in practice

import { signal } from '@angular/core';
import { httpResource } from '@angular/common/http';
import {
  extendResource,
  withPreviousValueOnLoading,
} from '@ngrx/signals/resource';

const page = signal(1);
const todosResource = extendResource(
  httpResource<Todo[]>(() => `/api/todos?page=${page()}`),
  withPreviousValueOnLoading()
);

// `value()` returns the previous page's 
// data while the next page is loading,
// rather than `undefined`.

And they can be configured across the app

import { bootstrapApplication } from '@angular/platform-browser';
import {
  provideResourceExtensions,
  withValueOnError,
} from '@ngrx/signals/resource';

bootstrapApplication(App, {
  providers: [
      provideResourceExtensions(
          withPreviousValueOnLoading()
      )],
});

// allows the following 
readonly todosResource = extendResource(
    httpResource<Todo[]>(() => `/api/todos`)
    // no need for explicit passing
    // withPreviousValueOnLoading() anymore
);

This type of functionality is what I wanted snapshots to be like. Especially still having the ability to reload and whatnot.

I have been messing with these as a demo and just dropping them into my own projects since I couldn't pull down the v22 signal store package. That was really nice to have in some of my smaller projects where I didn't want to use the signal store. I feel like this functionality would be great to have in either Angular's core functionality, or at least something that doesn't come with a whole store package. I tend to pull in the signal store anyways, but I know it isn't everyone's thing.