rxjs-observable-store

A state management solution implemented using RxJS to mimic Redux architecture.

Read my blog post State management in Angular with observable store services to learn more about how to use the rxjs-observable-store package to manage state in front-end applications.

Getting started

Prerequisites:
Lowest TypeScript support starts at version 3.5.

Installation:

npm install rxjs-observable-store --save

Usage example:

import {Store} from 'rxjs-observable-store';

class ExampleState {
    exampleText = 'initial text';
    exampleObject = {
        property1: {
            nestedValue: {
                value: 1000,
            },
        },
    };
}

class ExampleStore extends Store<ExampleState> {
    constructor() {
        super(new ExampleState());
    }

    updateExampleText() {
        this.setState({
            ...this.state,
            exampleText: 'updated text',
        });
    }

    updateNestedValue() {
        this.patchState(
            2000,
            'exampleObject',
            'property1',
            'nestedValue',
            'value'
        );
    }
}

class TestComponent {
    store: ExampleStore;

    constructor() {
        this.store = new ExampleStore();

        this.store.state$.subscribe(state => {
            // Logs the updated state on every state change
            console.log(state);
        });

        this.store.onChanges('exampleObject', 'property1', 'nestedValue', 'value').subscribe(value => {
            // Logs the updated value only when state.exampleObject.property1.nestedValue.value changes
            console.log(value);
        });

        setTimeout(() => {
            this.store.updateExampleText();
        }, 1000);

        setTimeout(() => {
            this.store.updateNestedValue();
        }, 2000);
    }
}

API

Store's public properties:

state: <S>
Current state snapshot.

state$: Observable<S>
RxJS Observable of state.

Store's public methods:

onChanges(...path: (string|number|symbol)[]): Observable<any>
Get an RxJS Observable of state at path used to subscribe to partial state changes.

setState(nextState: S): void
Set store's state to nextState.

patchState(value: any, ...path: (string|number|symbol)[]): void
Set store's state at path to value.

Notes:

When using TypeScript, errors are thrown for nonexisting path and wrong value type:
Path autocompletion works as well (9 levels deep):

npm