feat: use resource snapshots

Author: manfredsteyer

src/app/domains/luggage/data/with-min-weight.ts

@@ -0,0 +1,35 @@
+import {
+  linkedSignal,
+  Resource,
+  resourceFromSnapshots,
+  ResourceSnapshot,
+  Signal,
+} from '@angular/core';
+
+import { Luggage } from './luggage';
+
+export function withMinWeight(
+  input: Resource<Luggage[]>,
+  minWeight: Signal<number>,
+): Resource<Luggage[]> {
+  const derived = linkedSignal<
+    { snap: ResourceSnapshot<Luggage[]>; min: number },
+    ResourceSnapshot<Luggage[]>
+  >({
+    source: () => ({
+      snap: input.snapshot(),
+      min: minWeight(),
+    }),
+    computation: ({ snap, min }) => {
+      if (snap.status === 'resolved') {
+        return {
+          ...snap,
+          value: snap.value.filter((item) => item.weight >= min),
+        };
+      }
+      return snap;
+    },
+  });
+
+  return resourceFromSnapshots(derived);
+}

src/app/domains/luggage/feature-luggage/luggage-overview/simple-luggage-store.ts

@@ -1,12 +1,15 @@
 import { inject, Service, signal } from '@angular/core';
 
+import { withPreviousValue } from '../../../shared/util-common/with-previous-value';
 import { LuggageClient } from '../../data/luggage-client';
 
 @Service({ autoProvided: false })
 export class SimpleLuggageStore {
   private luggageClient = inject(LuggageClient);
 
-  private readonly luggageResource = this.luggageClient.findLuggage();
+  private readonly luggageResource = withPreviousValue(
+    this.luggageClient.findLuggage(),
+  );
   readonly luggage = this.luggageResource.value;
   readonly isLoading = this.luggageResource.isLoading;
   readonly error = this.luggageResource.error;