Mastering State Management in Angular: Demystifying NgRx, the Signal Store, and Events Plugin

1. mastering state management in Angular
2. Hi, I am Fabian
3. you have to deal with state
4. signals
5. what are signals?
6. 1 2 3 4 5 6 7 todos = signal<Todo[]>([]); todos(); todos.set(...); todos.update((items) => { /* ... */ });
7. 1 2 3 4 5 6 7 todos = signal<Todo[]>([]); todos(); todos.set(...); todos.update((items) => { /* ... */ });
8. 1 2 3 4 5 6 7 todos = signal<Todo[]>([]); todos(); todos.set(...); todos.update((items) => { /* ... */ });
9. 1 2 3 4 5 6 7 todos = signal<Todo[]>([]); todos(); todos.set(...); todos.update((items) => { /* ... */ });
10. 1 2 3 4 5 6 7 todos = signal<Todo[]>([]); todos(); todos.set(...); todos.update((items) => { /* ... */ });
11. 1 2 3 4 5 6 7 8 9 todos = signal<Todo[]>([]); count = computed(() => todos().length); editableCount = linkedSignal(() => todos().length); effect(() => { console.log('Todos count changed to ', count()); });
12. 1 2 3 4 5 6 7 8 9 todos = signal<Todo[]>([]); count = computed(() => todos().length); editableCount = linkedSignal(() => todos().length); effect(() => { console.log('Todos count changed to ', count()); });
13. 1 2 3 4 5 6 7 8 9 todos = signal<Todo[]>([]); count = computed(() => todos().length); editableCount = linkedSignal(() => todos().length); effect(() => { console.log('Todos count changed to ', count()); });
14. 1 2 3 4 5 6 7 8 9 todos = signal<Todo[]>([]); count = computed(() => todos().length); editableCount = linkedSignal(() => todos().length); effect(() => { console.log('Todos count changed to ', count()); });
15. but why?
16. optimized ui updates
17. zoneless
18. no subscribe
19. no subscribe no unsubscribe
20. rxjs interop
21. signals && observables
22. ways to use signals
23. component
24. 1 export class TodoMainComponent implements OnInit { private url = `${environment.apiUrl}todos`; 2 3 private http = inject(HttpClient); private todos = signal<Todo[]>([]); 4 5 count = computed(() => this.todos().length); 6 7 doneItems = computed(() => this.todos().filter((item) => item.done).length); 8 9 10 openItems = computed(() => this.todos().filter((item) => !item.done).length); 11 12 sortedTodos = computed(() => [...this.todos()].sort((a, b) => +a.done - +b.done 13 // Method logic with http... 14 15 }
25. 1 export class TodoMainComponent implements OnInit { private url = `${environment.apiUrl}todos`; 2 3 private http = inject(HttpClient); private todos = signal<Todo[]>([]); 4 5 6 count = computed(() => this.todos().length); 7 8 doneItems = computed(() => this.todos().filter((item) => item.done).length); 9 10 openItems = computed(() => this.todos().filter((item) => !item.done).length); 11 12 sortedTodos = computed(() => [...this.todos()].sort((a, b) => +a.done - +b.done 13 14 // Method logic with http... 15 }
26. 1 export class TodoMainComponent implements OnInit { 2 private url = `${environment.apiUrl}todos`; 3 private http = inject(HttpClient); 4 private todos = signal<Todo[]>([]); 5 count = computed(() => this.todos().length); 6 7 doneItems = computed(() => this.todos().filter((item) => item.done).length); 8 9 10 openItems = computed(() => this.todos().filter((item) => !item.done).length); 11 12 sortedTodos = computed(() => [...this.todos()].sort((a, b) => +a.done - +b.done 13 14 // Method logic with http... 15 }
27. service
28. service as abstraction
29. 1 @Injectable({ providedIn: 'root' }) 2 export class TodoService { 3 private url = `${environment.apiUrl}todos`; 4 private http = inject(HttpClient); 5 private todos = signal<Todo[]>([]); 6 7 count = computed(() => this.todos().length); 8 doneItems = computed(() => this.todos().filter((item) => item.done).length); 9 openItems = computed(() => this.todos().filter((item) => !item.done).length); 10 sortedTodos = computed(() => [...this.todos()].sort((a, b) => +a.done - +b.done)); 11 12 getItems() { 13 this.http.get<Todo[]>(this.url).subscribe((todos) => this.todos.set(todos)); 14 } 15 16 replaceItem() { 17 this.todos.update((items) => [...items]); 18 } 19 20 addItem(value: string) { 21 this.http.post<Todo>(this.url, { value }).subscribe((addedTodo) => { 22 this.todos.update((items) => [addedTodo, ...items]); 23 }); 24 } 25 26 updateItem(value: Todo) { 27 // ... 28 } 29 30 removeItem(id: string) { 31 this.http.delete(`${this.url}/${id}`).subscribe(() => { 32 this.todos.update((items) => [...items.filter((item) => item.id !== id)]); 33 }); 34 } 35 }
30. 1 @Injectable({ providedIn: 'root' }) 2 export class TodoService { 3 private url = `${environment.apiUrl}todos`; 4 private http = inject(HttpClient); 5 private todos = signal<Todo[]>([]); 6 7 count = computed(() => this.todos().length); 8 doneItems = computed(() => this.todos().filter((item) => item.done).length); 9 openItems = computed(() => this.todos().filter((item) => !item.done).length); 10 sortedTodos = computed(() => [...this.todos()].sort((a, b) => +a.done - +b.done)); 11 12 getItems() { 13 this.http.get<Todo[]>(this.url).subscribe((todos) => this.todos.set(todos)); 14 } 15 16 replaceItem() { 17 this.todos.update((items) => [...items]); 18 } 19 20 addItem(value: string) { 21 this.http.post<Todo>(this.url, { value }).subscribe((addedTodo) => { 22 this.todos.update((items) => [addedTodo, ...items]); 23 }); 24 } 25 26 updateItem(value: Todo) { 27 // ... 28 } 29 30 removeItem(id: string) { 31 this.http.delete(`${this.url}/${id}`).subscribe(() => { 32 this.todos.update((items) => [...items.filter((item) => item.id !== id)]); 33 }); 34 } 35 }
31. 1 @Injectable({ providedIn: 'root' }) 2 export class TodoService { 3 private url = `${environment.apiUrl}todos`; 4 private http = inject(HttpClient); 5 private todos = signal<Todo[]>([]); 6 7 count = computed(() => this.todos().length); 8 doneItems = computed(() => this.todos().filter((item) => item.done).length); 9 openItems = computed(() => this.todos().filter((item) => !item.done).length); 10 sortedTodos = computed(() => [...this.todos()].sort((a, b) => +a.done - +b.done)); 11 12 getItems() { 13 this.http.get<Todo[]>(this.url).subscribe((todos) => this.todos.set(todos)); 14 } 15 16 replaceItem() { 17 this.todos.update((items) => [...items]); 18 } 19 20 addItem(value: string) { 21 this.http.post<Todo>(this.url, { value }).subscribe((addedTodo) => { 22 this.todos.update((items) => [addedTodo, ...items]); 23 }); 24 } 25 26 updateItem(value: Todo) { 27 // ... 28 } 29 30 removeItem(id: string) { 31 this.http.delete(`${this.url}/${id}`).subscribe(() => { 32 this.todos.update((items) => [...items.filter((item) => item.id !== id)]); 33 }); 34 } 35 }
32. 1 @Injectable({ providedIn: 'root' }) 2 export class TodoService { 3 private url = `${environment.apiUrl}todos`; 4 private http = inject(HttpClient); 5 private todos = signal<Todo[]>([]); 6 7 count = computed(() => this.todos().length); 8 doneItems = computed(() => this.todos().filter((item) => item.done).length); 9 openItems = computed(() => this.todos().filter((item) => !item.done).length); 10 sortedTodos = computed(() => [...this.todos()].sort((a, b) => +a.done - +b.done)); 11 12 getItems() { 13 this.http.get<Todo[]>(this.url).subscribe((todos) => this.todos.set(todos)); 14 } 15 16 replaceItem() { 17 this.todos.update((items) => [...items]); 18 } 19 20 addItem(value: string) { 21 this.http.post<Todo>(this.url, { value }).subscribe((addedTodo) => { 22 this.todos.update((items) => [addedTodo, ...items]); 23 }); 24 } 25 26 updateItem(value: Todo) { 27 // ... 28 } 29 30 removeItem(id: string) { 31 this.http.delete(`${this.url}/${id}`).subscribe(() => { 32 this.todos.update((items) => [...items.filter((item) => item.id !== id)]); 33 }); 34 } 35 }
33. 1 export class TodoMainComponent implements OnInit { 2 private todoService = inject(TodoService); 3 4 count = this.todoService.count; doneItems = this.todoService.doneItems; 5 6 openItems = this.todoService.openItems; 7 sortedTodos = this.todoService.sortedTodos; 8 9 ngOnInit(): void { 10 this.todoService.getItems(); 11 } 12 13 addTodo(value: string) { 14 this.todoService.addItem(value); 15 } 16 17 deleteTodo(item: Todo): void { 18 this.todoService.removeItem(item.id); 19 } 20 21 markAsDone(item: Todo): void { 22 this.todoService.updateItem(item); 23 } 24 }
36. store
37. store as abstraction
38. logic store ui
39. logic store ui business logic, events, rxjs, websockets, ... computed, (a)sync glue signals, methods
40. 1 @Component({ /* ... */ }) 2 export class TodoMainComponent implements OnInit { 3 private readonly store = inject(Store); 4 5 items$ = this.store.select(getAllItems); 6 7 ngOnInit(): void { 8 this.store.dispatch(TodoActions.loadAllTodos()); 9 } 10 }
41. 1 @Component({ /* ... */ }) 2 export class TodoMainComponent implements OnInit { 3 private readonly store = inject(Store); 4 5 items$ = this.store.select(getAllItems); 6 7 ngOnInit(): void { 8 this.store.dispatch(TodoActions.loadAllTodos()); 9 } 10 }
42. 1 @Component({ /* ... */ }) 2 export class TodoMainComponent implements OnInit { 3 private readonly store = inject(Store); 4 5 items$ = this.store.select(getAllItems); 6 7 ngOnInit(): void { 8 this.store.dispatch(TodoActions.loadAllTodos()); 9 } 10 }
43. 1 @Component({ /* ... */ }) 2 export class TodoMainComponent implements OnInit { 3 private readonly store = inject(Store); 4 5 items$ = this.store.select(getAllItems); 6 7 ngOnInit(): void { 8 this.store.dispatch(TodoActions.loadAllTodos()); 9 } 10 }
44. 1 @Component({ /* ... */ }) 2 export class TodoMainComponent implements OnInit { 3 private readonly store = inject(Store); 4 5 items$ = this.store.select(getAllItems); 6 7 ngOnInit(): void { 8 this.store.dispatch(TodoActions.loadAllTodos()); 9 } 10 } 1 2 3 <app-todo-list [items]="items$ | async" ></app-todo-list>
45. 1 @Component({ /* ... */ }) 2 export class TodoMainComponent implements OnInit { 3 private readonly store = inject(Store); 4 5 items$ = this.store.select(getAllItems); 6 7 ngOnInit(): void { 8 this.store.dispatch(TodoActions.loadAllTodos()); 9 } 10 } 1 2 3 <app-todo-list [items]="items$ | async" ></app-todo-list>
46. 1 @Component({ /* ... */ }) 2 export class TodoMainComponent implements OnInit { 3 private readonly store = inject(Store); 4 5 items = this.store.selectSignal(getAllItems); 6 7 ngOnInit(): void { 8 this.store.dispatch(TodoActions.loadAllTodos()); 9 } 10 } 1 2 3 <app-todo-list [items]="items()" ></app-todo-list>
47. 1 @Component({ /* ... */ }) 2 export class TodoMainComponent implements OnInit { 3 private readonly store = inject(Store); 4 5 items = this.store.selectSignal(getAllItems); 6 7 ngOnInit(): void { 8 this.store.dispatch(TodoActions.loadAllTodos()); 9 } 10 } 1 2 3 <app-todo-list [items]="items()" ></app-todo-list>
49. partly signals
50. partly signals partly rxjs
53. the ngrx signal store
54. lightweight
55. functional based
56. highly extensible
57. optional rxjs
58. 1 2 3 4 5 6 7 8 9 10 11 export const TodoStore = signalStore( 12 13 );
59. 1 2 3 4 5 6 7 8 9 10 11 export const TodoStore = signalStore( 12 withState(...), 13 );
60. 1 2 3 4 5 6 7 8 9 10 11 12 13 export interface TodoState { items: Todo[]; loading: boolean; } export const initialState: TodoState = { items: [], loading: false, }; export const TodoStore = signalStore( withState(initialState), );
61. 1 2 3 4 5 6 7 8 9 10 11 12 13 export interface TodoState { items: Todo[]; loading: boolean; } export const initialState: TodoState = { items: [], loading: false, }; export const TodoStore = signalStore( withState(initialState), );
62. 1 2 3 4 5 6 7 8 9 10 11 12 13 export interface TodoState { items: Todo[]; loading: boolean; } export const initialState: TodoState = { items: [], loading: false, }; export const TodoStore = signalStore( withState(initialState), );
63. 1 2 3 4 5 6 7 8 9 10 11 12 13 export interface TodoState { items: Todo[]; loading: boolean; } export const initialState: TodoState = { items: [], loading: false, }; export const TodoStore = signalStore( withState(initialState), );
64. 1 export const TodoStore = signalStore( 2 withState({ /* ... */ }), 3 withMethods((...) => ({ 4 // ... 5 })) 6 );
65. 1 export const TodoStore = signalStore( 2 withState({ /* ... */ }), 3 withMethods((...) => ({ 4 // ... 5 })) 6 );
66. 1 export const TodoStore = signalStore( 2 withState({ /* ... */ }), 3 withMethods((store, todoService = inject(TodoService)) => ({ 4 loadAllTodos() { 5 // use TodoService and then 6 patchState(store, { items }); 7 }, 8 })) 9 );
67. 1 export const TodoStore = signalStore( 2 withState({ /* ... */ }), 3 withMethods((store, todoService = inject(TodoService)) => ({ 4 loadAllTodos() { 5 // use TodoService and then 6 patchState(store, { items }); 7 }, 8 })) 9 );
68. 1 export const TodoStore = signalStore( 2 withState({ /* state goes here */ }), 3 withMethods((store, todoService = inject(TodoService)) => ({ 4 loadAllTodos: rxMethod<void>( 5 switchMap(() => { 6 patchState(store, {loading: true}); 7 8 return todoService.getItems().pipe( 9 tapResponse({ 10 next: (items) => patchState(store, {items}), 11 error: console.error, 12 finalize: () => patchState(store, {loading: false}), 13 }) 14 ); 15 }) 16 ), 17 })) 18 );
69. 1 export const TodoStore = signalStore( 2 withState({ /* state goes here */ }), 3 withMethods((store, todoService = inject(TodoService)) => ({ 4 loadAllTodos: rxMethod<void>( 5 switchMap(() => { 6 patchState(store, {loading: true}); 7 8 return todoService.getItems().pipe( 9 tapResponse({ 10 next: (items) => patchState(store, {items}), 11 error: console.error, 12 finalize: () => patchState(store, {loading: false}), 13 }) 14 ); 15 }) 16 ), 17 })) 18 );
70. 1 export const TodoStore = signalStore( 2 withState({ /* state goes here */ }), 3 withMethods((store, todoService = inject(TodoService)) => ({ 4 loadAllTodos: rxMethod<void>( 5 switchMap(() => { 6 patchState(store, {loading: true}); 7 8 return todoService.getItems().pipe( 9 tapResponse({ 10 next: (items) => patchState(store, {items}), 11 error: console.error, 12 finalize: () => patchState(store, {loading: false}), 13 }) 14 ); 15 }) 16 ), 17 })) 18 );
71. 1 export const TodoStore = signalStore( 2 withState({ /* state goes here */ }), 3 withMethods((store, todoService = inject(TodoService)) => ({ 4 loadAllTodos: rxMethod<void>( 5 switchMap(() => { 6 patchState(store, {loading: true}); 7 8 return todoService.getItems().pipe( 9 tapResponse({ 10 next: (items) => patchState(store, {items}), 11 error: console.error, 12 finalize: () => patchState(store, {loading: false}), 13 }) 14 ); 15 }) 16 ), 17 })) 18 );
72. 1 export const TodoStore = signalStore( 2 withState({ /* state goes here */ }), 3 withMethods((store, todoService = inject(TodoService)) => ({ 4 loadAllTodos: rxMethod<void>( 5 switchMap(() => { 6 patchState(store, {loading: true}); 7 8 return todoService.getItems().pipe( 9 tapResponse({ 10 next: (items) => patchState(store, {items}), 11 error: console.error, 12 finalize: () => patchState(store, {loading: false}), 13 }) 14 ); 15 }) 16 ), 17 })) 18 );
73. optional rxjs
74. 1 export const TodoStore = signalStore( 2 withState({ /* state goes here */ }), 3 withMethods((store, todoService = inject(TodoService)) => ({ 4 loadAllTodos: rxMethod<void>(/* ... */), 5 6 async loadAllTodosByPromise() { 7 patchState(store, { loading: true }); 8 9 const items = await todoService.getItemsAsPromise(); 10 11 patchState(store, { items, loading: false }); 12 }, 13 })) 14 );
75. 1 export const TodoStore = signalStore( 2 withState({ /* state goes here */ }), 3 withMethods((store, todoService = inject(TodoService)) => ({ 4 loadAllTodos: rxMethod<void>(/* ... */), 5 6 async loadAllTodosByPromise() { 7 patchState(store, { loading: true }); 8 9 const items = await todoService.getItemsAsPromise(); 10 11 patchState(store, { items, loading: false }); 12 }, 13 })) 14 );
76. 1 2 3 4 5 6 7 8 9 10 11 @Component({ // ... providers: [TodoStore], }) export class AppComponent implements OnInit { readonly store = inject(TodoStore); ngOnInit() { this.store.loadAllTodos(); } }
77. 1 2 3 4 5 6 7 8 9 10 11 @Component({ // ... providers: [TodoStore], }) export class AppComponent implements OnInit { readonly store = inject(TodoStore); ngOnInit() { this.store.loadAllTodos(); } }
78. 1 2 3 4 5 6 7 8 9 10 11 @Component({ // ... providers: [TodoStore], }) export class AppComponent implements OnInit { readonly store = inject(TodoStore); ngOnInit() { this.store.loadAllTodos(); } }
79. 1 2 3 4 5 6 7 8 9 10 11 @Component({ // ... providers: [TodoStore], }) export class AppComponent implements OnInit { readonly store = inject(TodoStore); ngOnInit() { this.store.loadAllTodos(); } }
80. 1 2 3 4 5 6 7 8 9 10 11 12 @Component({ // ... template: `{{ store.items() }} {{ store.loading() }}`, providers: [TodoStore], }) export class AppComponent implements OnInit { readonly store = inject(TodoStore); ngOnInit() { this.store.loadAllTodos(); } }
81. 1 export const TodoStore = signalStore( 2 withState(initialState), 3 withMethods(/* ... */), 4 withHooks({ 5 // Hooks 6 }) 7 );
82. 1 export const TodoStore = signalStore( 2 withState(initialState), 3 withMethods(/* ... */), 4 withHooks({ 5 // Hooks 6 }) 7 );
83. 1 export const TodoStore = signalStore( 2 withState(initialState), 3 withMethods(/* ... */), 4 withHooks({ 5 onInit({ loadAllTodos }) { 6 loadAllTodos(); 7 }, 8 onDestroy() { 9 console.log('on destroy'); 10 }, 11 }) 12 );
84. 1 export const TodoStore = signalStore( 2 withState(initialState), 3 withMethods(/* ... */), 4 withHooks({ 5 onInit({ loadAllTodos }) { 6 loadAllTodos(); 7 }, 8 onDestroy() { 9 console.log('on destroy'); 10 }, 11 }) 12 );
85. 1 2 3 4 5 6 7 8 9 10 11 @Component({ // ... providers: [TodoStore], }) export class AppComponent implements OnInit { readonly store = inject(TodoStore); ngOnInit() { this.store.loadAllTodos(); } }
86. 1 2 3 4 5 6 7 @Component({ // ... providers: [TodoStore], }) export class AppComponent { readonly store = inject(TodoStore); }
87. 1 export const TodoStore = signalStore( 2 withState(initialState), 3 4 withComputed((state) => ({ 5 /* ... */ 6 })), 7 8 withMethods(/* ... */), 9 withHooks(/* ... */) 10 );
88. 1 export const TodoStore = signalStore( 2 withState(initialState), 3 4 withComputed(({ items }) => ({ doneCount: computed(() => items().filter((x) => x.done).length), 5 6 undoneCount: computed(() => items().filter((x) => !x.done).length), 7 percentageDone: computed(() => { 8 const done = items().filter((x) => x.done).length; 9 const total = items().length; 10 11 if (total === 0) { 12 return 0; 13 } 14 15 return (done / total) * 100; 16 }), 17 })), 18 19 withMethods(/* ... */), 20 withHooks(/* ... */) 21 );
89. 1 export const TodoStore = signalStore( 2 withState(initialState), 3 4 withComputed(({ items }) => ({ doneCount: computed(() => items().filter((x) => x.done).length), 5 6 undoneCount: computed(() => items().filter((x) => !x.done).length), 7 percentageDone: computed(() => { 8 const done = items().filter((x) => x.done).length; 9 const total = items().length; 10 11 if (total === 0) { 12 return 0; 13 } 14 15 return (done / total) * 100; 16 }), 17 })), 18 19 withMethods(/* ... */), 20 withHooks(/* ... */) 21 );
90. 1 export const TodoStore = signalStore( 2 withState(initialState), 3 4 withComputed(({ items }) => ({ doneCount: computed(() => items().filter((x) => x.done).length), 5 6 undoneCount: computed(() => items().filter((x) => !x.done).length), 7 percentageDone: computed(() => { 8 const done = items().filter((x) => x.done).length; 9 const total = items().length; 10 11 if (total === 0) { 12 return 0; 13 } 14 15 return (done / total) * 100; 16 }), 17 })), 18 19 withMethods(/* ... */), 20 withHooks(/* ... */) 21 );
91. 1 export const TodoStore = signalStore( 2 withState(initialState), 3 4 withComputed(({ items }) => ({ 5 doneCount: computed(() => items().filter((x) => x.done).length), 6 undoneCount: computed(() => items().filter((x) => !x.done).length), 7 percentageDone: computed(() => { 8 const done = items().filter((x) => x.done).length; 9 const total = items().length; 10 11 if (total === 0) { 12 return 0; 13 } 14 15 return (done / total) * 100; 16 }), 17 })), 18 19 withMethods(/* ... */), 20 withHooks(/* ... */) 21 );
92. 1 export const TodoStore = signalStore( 2 withState(initialState), 3 4 withComputed(({ items }) => ({ 5 doneCount: computed(() => items().filter((x) => x.done).length), 6 undoneCount: computed(() => items().filter((x) => !x.done).length), 7 percentageDone: computed(() => { 8 const done = items().filter((x) => x.done).length; 9 const total = items().length; 10 11 if (total === 0) { 12 return 0; 13 } 14 15 return (done / total) * 100; 16 }), 17 })), 18 19 withMethods(/* ... */), 20 withHooks(/* ... */) 21 );
93. 1 2 3 4 5 6 7 8 9 10 11 @Component({ providers: [TodoStore], template: ` <div> {{ store.doneCount() }} / {{ store.undoneCount() }} {{ store.percentageDone() }} </div> ` }) export class AppComponent { readonly store = inject(TodoStore); }
94. 1 2 3 4 5 6 7 8 9 10 11 @Component({ providers: [TodoStore], template: ` <div> {{ store.doneCount() }} / {{ store.undoneCount() }} {{ store.percentageDone() }} </div> ` }) export class AppComponent { readonly store = inject(TodoStore); }
97. custom features
98. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 import { computed } from '@angular/core'; import { signalStoreFeature, withComputed, withState } from '@ngrx/signals'; export type RequestStatus = 'idle' | 'pending' | 'fulfilled' | { error: string }; export type RequestStatusState = { requestStatus: RequestStatus }; export function withRequestStatus() { return signalStoreFeature( withState<RequestStatusState>({ requestStatus: 'idle' }), withComputed(({ requestStatus }) => ({ isPending: computed(() => requestStatus() === 'pending'), isFulfilled: computed(() => requestStatus() === 'fulfilled'), error: computed(() => { const status = requestStatus(); return typeof status === 'object' ? status.error : null; }), })) ); }
99. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 import { computed } from '@angular/core'; import { signalStoreFeature, withComputed, withState } from '@ngrx/signals'; export type RequestStatus = 'idle' | 'pending' | 'fulfilled' | { error: string }; export type RequestStatusState = { requestStatus: RequestStatus }; export function withRequestStatus() { return signalStoreFeature( withState<RequestStatusState>({ requestStatus: 'idle' }), withComputed(({ requestStatus }) => ({ isPending: computed(() => requestStatus() === 'pending'), isFulfilled: computed(() => requestStatus() === 'fulfilled'), error: computed(() => { const status = requestStatus(); return typeof status === 'object' ? status.error : null; }), })) ); }
100. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 import { computed } from '@angular/core'; import { signalStoreFeature, withComputed, withState } from '@ngrx/signals'; export type RequestStatus = 'idle' | 'pending' | 'fulfilled' | { error: string }; export type RequestStatusState = { requestStatus: RequestStatus }; export function withRequestStatus() { return signalStoreFeature( withState<RequestStatusState>({ requestStatus: 'idle' }), withComputed(({ requestStatus }) => ({ isPending: computed(() => requestStatus() === 'pending'), isFulfilled: computed(() => requestStatus() === 'fulfilled'), error: computed(() => { const status = requestStatus(); return typeof status === 'object' ? status.error : null; }), })) ); }
101. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 import { computed } from '@angular/core'; import { signalStoreFeature, withComputed, withState } from '@ngrx/signals'; export type RequestStatus = 'idle' | 'pending' | 'fulfilled' | { error: string }; export type RequestStatusState = { requestStatus: RequestStatus }; export function withRequestStatus() { return signalStoreFeature( withState<RequestStatusState>({ requestStatus: 'idle' }), withComputed(({ requestStatus }) => ({ isPending: computed(() => requestStatus() === 'pending'), isFulfilled: computed(() => requestStatus() === 'fulfilled'), error: computed(() => { const status = requestStatus(); return typeof status === 'object' ? status.error : null; }), })) ); }
102. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 import { computed } from '@angular/core'; import { signalStoreFeature, withComputed, withState } from '@ngrx/signals'; export type RequestStatus = 'idle' | 'pending' | 'fulfilled' | { error: string }; export type RequestStatusState = { requestStatus: RequestStatus }; export function withRequestStatus() { return signalStoreFeature( withState<RequestStatusState>({ requestStatus: 'idle' }), withComputed(({ requestStatus }) => ({ isPending: computed(() => requestStatus() === 'pending'), isFulfilled: computed(() => requestStatus() === 'fulfilled'), error: computed(() => { const status = requestStatus(); return typeof status === 'object' ? status.error : null; }), })) ); }
103. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 import { computed } from '@angular/core'; import { signalStoreFeature, withComputed, withState } from '@ngrx/signals'; export type RequestStatus = 'idle' | 'pending' | 'fulfilled' | { error: string }; export type RequestStatusState = { requestStatus: RequestStatus }; export function withRequestStatus() { return signalStoreFeature( withState<RequestStatusState>({ requestStatus: 'idle' }), withComputed(({ requestStatus }) => ({ isPending: computed(() => requestStatus() === 'pending'), isFulfilled: computed(() => requestStatus() === 'fulfilled'), error: computed(() => { const status = requestStatus(); return typeof status === 'object' ? status.error : null; }), })) ); }
104. 1 2 3 4 5 6 7 8 9 10 11 export function setPending(): RequestStatusState { return { requestStatus: 'pending' }; } export function setFulfilled(): RequestStatusState { return { requestStatus: 'fulfilled' }; } export function setError(error: string): RequestStatusState { return { requestStatus: { error } }; }
105. 1 2 3 4 5 6 7 8 9 10 11 12 13 export const TodoStore = signalStore( withState(initialState), withRequestStatus(), withComputed(/* ... */), withMethods(/* ... */), withHooks(/* ... */) ); readonly store = inject(TodoStore); store.requestStatus(); store.isPending(); store.isFulfilled();
106. 1 2 3 4 5 6 7 8 9 10 11 12 13 export const TodoStore = signalStore( withState(initialState), withRequestStatus(), withComputed(/* ... */), withMethods(/* ... */), withHooks(/* ... */) ); readonly store = inject(TodoStore); store.requestStatus(); store.isPending(); store.isFulfilled();
107. 1 2 3 4 5 6 7 8 9 10 11 12 13 export const TodoStore = signalStore( withState(initialState), withRequestStatus(), withComputed(/* ... */), withMethods(/* ... */), withHooks(/* ... */) ); readonly store = inject(TodoStore); store.requestStatus(); store.isPending(); store.isFulfilled();
108. 1 2 3 4 5 6 7 8 9 10 11 12 13 export const TodoStore = signalStore( withState(initialState), withRequestStatus(), withComputed(/* ... */), withMethods(/* ... */), withHooks(/* ... */) ); readonly store = inject(TodoStore); store.requestStatus(); store.isPending(); store.isFulfilled();
109. extend state
110. demo webstore
111. the signal store events plugin
113. actions
114. import { createActionGroup, emptyProps, props } from '@ngrx/store'; export const usersPageActions = createActionGroup({ source: 'Users Page', events: { 'Opened': emptyProps(), 'Refreshed': emptyProps(), }, }); export const usersApiActions = createActionGroup({ source: 'Users API', events: { 'Users Loaded Success': props<{ users: User[] }>(), 'Users Loaded Error': props<{ error: string }>(), }, });
115. import { type } from '@ngrx/signals'; import { eventGroup } from '@ngrx/signals/events'; export const usersPageEvents = eventGroup({ source: 'Users Page', events: { opened: type<void>(), refreshed: type<void>(), }, }); export const usersApiEvents = eventGroup({ source: 'Users API', events: { usersLoadedSuccess: type<User[]>(), usersLoadedError: type<string>(), }, });
116. reducer
117. export const usersReducer = createReducer( initialUsersState, on(usersPageActions.opened, usersPageActions.refreshed, (state) => ({ ...state, requestStatus: 'pending', })), on(usersApiActions.usersLoadedSuccess, (state, { users }) => ({ ...state, users, requestStatus: 'fulfilled', })), on(usersApiActions.usersLoadedError, (state, { error }) => ({ ...state, requestStatus: { error }, })), );
118. import { on, withReducer } from '@ngrx/signals/events'; export const UsersStore = signalStore( { providedIn: 'root' }, withEntities<User>(), withRequestStatus(), withReducer( on(usersPageEvents.opened, usersPageEvents.refreshed, setPending), on(usersApiEvents.usersLoadedSuccess, ({ payload }) => [ setAllEntities(payload), setFulfilled(), ]), on(usersApiEvents.usersLoadedError, ({ payload }) => setError(payload)), ), );
119. effects
120. export const loadUsers$ = createEffect( (actions$ = inject(Actions), usersService = inject(UsersService)) => actions$.pipe( ofType(usersPageActions.opened, usersPageActions.refreshed), exhaustMap(() => usersService.getAll().pipe( map((users) => usersApiActions.usersLoadedSuccess({ users })), catchError((error: { message: string }) => of(usersApiActions.usersLoadedError({ error: error.message })), ), ), ), ), { functional: true }, );
121. export const UsersStore = signalStore( /* ... */ withEventHandlers( (_, events = inject(Events), usersService = inject(UsersService)) => ({ loadUsers$: events .on(usersPageEvents.opened, usersPageEvents.refreshed) .pipe( exhaustMap(() => usersService.getAll().pipe( mapResponse({ next: (users) => usersApiEvents.usersLoadedSuccess(users), error: (error: { message: string }) => usersApiEvents.usersLoadedError(error.message), }), ), ), ), logError$: events .on(usersApiEvents.usersLoadedError) .pipe(tap(({ payload }) => console.log(payload))), }), ), );
122. reading
123. @Component({ selector: 'app-users', template: ` <h1>Users</h1> @if (usersStore.isPending()) { <p>Loading...</p> } <ul> @for (user of usersStore.entities(); track user.id) { <li>{{ user.name }}</li> } </ul> `, }) export class UsersComponent { readonly usersStore = inject(UsersStore); }
124. dispatching events
125. @Component({ template: ` <h1>Users</h1> <button (click)="onRefresh()">Refresh</button> <!-- ... --> `, }) export class UsersComponent implements OnInit { readonly usersStore = inject(UsersStore); readonly dispatcher = inject(Dispatcher); ngOnInit() { this.dispatcher.dispatch(usersPageEvents.opened()); } onRefresh(): void { this.dispatcher.dispatch(usersPageEvents.refreshed()); } }
126. demo nx workspace
128. Component State Feature State App State
129. classic store
130. classic store signal store
131. classic store signal store signal store events plugin
132. classic store signal store signal store events plugin
133. classic store signal store signal store events plugin biggest and clearest separation actions, reducer, effects, store, ...
134. classic store signal store signal store events plugin biggest and clearest separation actions, reducer, effects, store, ... each store as a service no separate actions, reducer, etc. extensible with custom features calling methods on store
135. classic store signal store signal store events plugin biggest and clearest separation actions, reducer, effects, store, ... each store as a service no separate actions, reducer, etc. extensible with custom features calling methods on store everything signal store has actions, reducer, effects separated dispatching actions signal store w/ classic ngrx
136. start with the signal store. add events when you need decoupling.
137. you have to deal with state
138. https://github.com/FabianGosebrink/sample-ngrx-webstore-app https://github.com/FabianGosebrink/dog-rate-app