feat: entities array observable in data entity collections (#619)

* feat: entities array observable in data entity collections

* feat: entities array observable test

* feat: entities array observable doc

Author: andrewDyakin

docs/pages/state-repository.md

@@ -82,6 +82,7 @@ class ArticleEntitiesState extends NgxsDataEntityCollectionsRepository<Article>
 | state.snapshot                                      | NgxsEntityCollections&lt;V, K&gt;                   | Memoized state value (getter)                                               |
 | state.reset()                                       | void                                                | Reset state with default state value                                        |
 | state.state\$                                       | Observable&lt;NgxsEntityCollections&lt;V, K&gt;&gt; | State data stream that you can subscribe to changes                         |
+| state.entityArray\$                                 | Observable&lt;V[]&gt;                               | Observable of entities array                                                |
 | dispatch(actions: ActionType &verbar; ActionType[]) | void                                                | Standard dispatch method                                                    |
 | state.addOne(entity: V)                             | void                                                | Add one entity to the collection                                            |
 | state.addMany(entities: V[])                        | void                                                | Add multiple entities to the collection                                     |

integration/tests/entity/observables.spec.ts

@@ -0,0 +1,109 @@
+import { StateRepository } from '@ngxs-labs/data/decorators';
+import { State } from '@ngxs/store';
+import { createEntityCollections } from '@angular-ru/common/entity';
+import { NgxsDataEntityCollectionsRepository } from '@ngxs-labs/data/repositories';
+import { ngxsTestingPlatform } from '@ngxs-labs/data/testing';
+import { Injectable } from '@angular/core';
+
+
+describe('[TEST]: Entity observables', () => {
+    describe('entityArray$', () => {
+        interface StudentEntity {
+            id: number;
+            name: string;
+        }
+
+        @StateRepository()
+        @State({
+            name: 'student',
+            defaults: createEntityCollections()
+        })
+        @Injectable()
+        class StudentEntitiesState extends NgxsDataEntityCollectionsRepository<StudentEntity, string> {}
+
+        it(
+            'correct create entity arrays',
+            ngxsTestingPlatform([StudentEntitiesState], (_store, studentEntities) => {
+                const entityArrayEvents: StudentEntity[][] = [];
+
+                studentEntities.entitiesArray$.subscribe((entities) => {
+                    entityArrayEvents.push(entities)
+                });
+
+                studentEntities.setAll([
+                    {
+                        id: 1,
+                        name: 'Maxim',
+                    },
+                    {
+                        id: 2,
+                        name: 'Ivan',
+                    },
+                    {
+                        id: 3,
+                        name: 'Nikola',
+                    },
+                    {
+                        id: 4,
+                        name: 'Petr',
+                    }
+                ]);
+                
+                studentEntities.reset();
+
+                studentEntities.addOne({
+                    id: 1,
+                    name: 'Maxim',
+                });
+
+                studentEntities.removeAll();
+
+                const entity: StudentEntity = {
+                    id: 4,
+                    name: 'Mark',
+                };
+
+                studentEntities.upsertOne(entity);
+
+                studentEntities.removeByEntity(entity);
+                
+                expect(entityArrayEvents).toEqual([
+                    [],
+                    [
+                        {
+                            id: 1,
+                            name: 'Maxim',
+                        },
+                        {
+                            id: 2,
+                            name: 'Ivan',
+                        },
+                        {
+                            id: 3,
+                            name: 'Nikola',
+                        },
+                        {
+                            id: 4,
+                            name: 'Petr',
+                        }
+                    ],
+                    [],
+                    [
+                        {
+                            id: 1,
+                            name: 'Maxim',
+                        }
+                    ],
+                    [],
+                    [
+                        {
+                            id: 4,
+                            name: 'Mark',
+                        }
+                    ],
+                    []
+                ]);
+            })
+        );
+    });
+});

lib/repositories/src/ngxs-data-entity-collections/ngxs-data-entity-collections.repository.ts

@@ -59,6 +59,13 @@ export abstract class AbstractNgxsDataEntityCollectionsRepository<
         return this.state$.pipe(map((value: EntityCollections<V, K, C>): EntityDictionary<K, V> => value.entities));
     }
 
+    @Computed()
+    public get entitiesArray$(): Observable<V[]> {
+        return this.state$.pipe(
+            map((value: EntityCollections<V, K, C>): V[] => value.ids.map(id => value.entities[id]))
+        );
+    }
+
     protected get ctx(): EntityContext<V, K, C> {
         return ensureDataStateContext<EntityCollections<V, K, C>, StateContext<EntityCollections<V, K, C>>>(
             this.context as StateContext<EntityCollections<V, K, C>>