@ngx-odm/rxdb

> Angular 17+ wrapper for RxDB - A realtime Database for the Web

Demo

!Example Screencast

demo - based on TodoMVC

Table of contents

- @ngx-odm/rxdb
- Demo
- Table of contents
- General info
- Technologies
- Install
- Usage (NgModule)
- In your AppModule
- In your FeatureModule
- In your FeatureService
- Usage (Standalone)
- In your main.ts
- In your Component
- Using sginals \& signalStore from @ngrx/signals
- Features
- Status
- Inspiration
- Notes
- Contact

General info

If you don't want to setup RxDB manually in your next Angular project - just import NgxRxdbModule or go with provideRxDatabase and provideRxCollection if standalone component is your choice.

Technologies

| RxDB 16+ | Angular 17+ |
| -------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------- |
|  |  |

Install

npm install @ngx-odm/rxdb

Usage (NgModule)

$3

``typescript
import { NgxRxdbModule } from '@ngx-odm/rxdb';
import { getRxDatabaseCreator } from '@ngx-odm/rxdb/config';

@NgModule({
imports: [
// ... other imports
NgxRxdbModule.forRoot(
getRxDatabaseCreator({
name: 'demo', // <- name (required, 'ngx')
storage: getRxStorageDexie(), // <- storage (not required, 'dexie')
localDocuments: true,
multiInstance: true, // <- multiInstance (optional, default: true)
ignoreDuplicate: false,
options: {
plugins: [
// will be loaded by together with core plugins
RxDBDevModePlugin, // <- add only for development
RxDBAttachmentsPlugin,
RxDBLeaderElectionPlugin,
],
storageType: 'dexie|memory', // <- storageType (optional, use if you want defaults provided automatically)
dumpPath: 'assets/dump.json', // path to datbase dump file (optional)
},
})
),
],
providers: [],
bootstrap: [AppComponent],
})
export class AppModule {}
`

$3

> Schemas define how your data looks. Which field should be used as primary, which fields should be used as indexes and what should be encrypted. The schema also validates that every inserted document of your collections conforms to the schema. Every collection has its own schema. With RxDB, schemas are defined with the jsonschema-standard which you might know from other projects.
> https://rxdb.info/rx-schema.html

`typescript
import type { RxCollectionCreatorExtended } from '@ngx-odm/rxdb/config';
// create or import your schema
const todoSchema: RxSchema = require('../../../assets/data/todo.schema.json');
// create config
const todoCollectionConfig: RxCollectionCreatorExtended = {
name: 'todo', // <- name (required)
schema: todoSchema, // <- schema (not required, see below)
localDocuments: true,
options: {
initialDocs: [], // docs to be imported into empty collection (optional)
schemaUrl: 'assets/data/todo.schema.json', // load schema from remote url (optional)
replicationStateFactory: collection => {
// provide replication state (optional)
},
},
};

@NgModule({
imports: [
// ... other imports
NgxRxdbModule.forFeature(todoCollectionConfig),
],
})
export class TodosModule {
constructor(
@Inject(RXDB_COLLECTION) private collectionService: RxDBCollectionService
) {
this.collectionService.sync(); // INFO: collection is ready
}
}
`

$3

`typescript
import { RXDB_COLLECTION } from '@ngx-odm/rxdb';
import { RxDBCollectionService } from '@ngx-odm/rxdb/collection';

@Injectable()
export class TodosService {
private collectionService: RxDBCollectionService =
inject>(RXDB_COLLECTION);
// store & get filter as property of a local document
filter$ = this.collectionService
.getLocal('local', 'filterValue')
.pipe(startWith('ALL'), distinctUntilChanged());
// get count of documents in collection as observable
count$ = this.collectionService.count();

// get documents from collection as observable
// optionally using RxQuery mango-queries
todos$: Observable = this.collectionService.docs();

// add new document
add(name: string): void {
const payload: Todo = { guid: uuid(), name, done: false, dateCreated: Date.now() };
this.collectionService.insert(payload);
}

// update property of single document
toggle(guid: string, done: boolean): void {
this.collectionService.set(guid, { done });
}

// update many documents with partial data by query
toggleAllTodos(completed: boolean) {
this.collectionService.updateBulk(
{ selector: { completed: { $eq: !completed } } },
{ completed }
);
}

// remove many dcouments by qeury
removeCompletedTodos(): void {
this.collectionService.removeBulk({ selector: { completed: true } });
}
// ...
}
`

Usage (Standalone)

$3

`typescript
import { provideRxDatabase } from '@ngx-odm/rxdb';
import { getRxDatabaseCreator } from '@ngx-odm/rxdb/config';

export const appConfig: ApplicationConfig = {
providers: [
// ... other providers
provideRxDatabase(
getRxDatabaseCreator({
name: 'demo',
localDocuments: true,
multiInstance: true,
ignoreDuplicate: false,
storage: getRxStorageDexie(),
plugins: [
// will be loaded by together with core plugins
RxDBDevModePlugin, // <- add only for development
RxDBAttachmentsPlugin,
RxDBLeaderElectionPlugin,
],
})
),
],
};

bootstrapApplication(AppComponent, appConfig).catch(err => console.error(err));
`

$3

`typescript
import { provideRxCollection } from '@ngx-odm/rxdb';

@Component({
standalone: true,
// ...
providers: [provideRxCollection(config)],
})
export class StandaloneComponent {
readonly todoCollection = inject(NgxRxdbCollectionService);
}
`

$3

`typescript
import { signalStore } from '@ngrx/signals';
import { withEntities } from '@ngrx/signals/entities';
import { withCollectionService } from '@ngx-odm/rxdb/signals';
import { withDevtools } from '@angular-architects/ngrx-toolkit';

export const TodoStore = signalStore(
{ providedIn: 'root' },
withDevtools('todo'),
withEntities(),
// INFO: an instance of RxCollection will be provided by this
withCollectionService({
filter: 'ALL' as TodosFilter,
collectionConfig: TodosCollectionConfig,
}),
...
);

@Component({
standalone: true,
// ...
providers: [TodoStore],
})
export class StandaloneComponent {
readonly todoStore = inject(TodoStore);

constructor() {
effect(() => {
const { filter, entities } = this.todoStore;
});
}
}
`

Features

By using this module you can simplify your work with RxDB in Angular application:

- Automatically initialize db with settings
- optionally provide db dumb to pre-fill collections
- optionally provide array of initial documents to pre-fill collection
- optionally provide remote location for schema and fetch it automatically before create collection (e.g. to maintain single source of truth for schema)
- optionally provide syncronization with remote db (CouchDB, Kinto etc.) as DB options
- Automatically initialize RxCollection for each _lazy-loaded Feature module / standalone component_ with config
- Work with documents via _NgxRxdbCollectionService_ with unified methods instead of using _RxCollection_ directly (though you still have access to _RxCollection_ and _RxDatabase_ instance)
- simple methods to work database & documents (with queries)
- simple methods to work with local documents
- simple methods to work with attachments
- simple replication sync initialization
- Work with signals and entities with @ngrx/signals and @ngrx/entity (supports native zoneless via provideZonelessChangeDetection()) (see example)
- Persist collection query (mango-query-syntax) in URL with new plugin query-params-plugin (in demo, set localStorage _ngx_rxdb_queryparams )
- provide Observable of current URL (automatically for Angular)
- simple methods to set or patch filter, sort, limit, skip

Status

Project is: _in progress_

Inspiration

Project inspired by

- rxdb-angular2-example
- Angular NgRx Material Starter
- _The Angular Library Series_ from Angular In Depth
- NgRx Toolkit - inspired by Manfred Steyer and created singnals tool by analogy of withDataService` from Angular Architects

Notes

Contact

Created by @voznik - feel free to contact me!