Resource-store

Small state management library based on RxJS. Resources-tore is state container designed to spread reactive state management accross your application.

Installation

Install resource-store from npm:

npm install @claudiucelfilip/resource-store

Basic Usage

import { IResourceOptions, ResourceStore, IResourceConnector, symbol, IResource } from '@claudiucelfilip/resource-store';

const store: ResourceStore = new ResourceStore();
const options1: IResourceOptions = {
  initialState: {
    items: [],
    text: 'string text',
    value: 4,
    obj1: {
      obj2: {
        label: 'string label',
        value: 'string label2'
      }
    }
  }
};

const resourceOne: IResource = store.create('resource-one', options1);
store.create('resource-two', options2);

resourceOne.value; // access to the current state of the resource (inherited from BehaviorSubject)

resourceOne.text.value === resourceOne.value.text;
resourceOne.value$.value === 4; // appending $ to any property name will assure that it doesn't conflict with any other Resource

resourceOne.obj1.obj2.update({
  label: 'new string label'
}); // will only update the label property from obj2. This change event will bubble through the tree

resourceOne[symbol.id]; // nonconflicting access to unique id
resourceOne[symbol.key]; // nonconflicting accesto to defined key (ie. 'resource-one')

Sync with external storage

class SimpleConnector implements IResourceConnector {
  save (context?: ResourceStore | any): Promise<any> {
    return // Promise to sync with external store
  }
  fetch (context?: ResourceStore | any): Promise<any> {
    return // Promise to fetch from external store
  }
}

const options2: IResourceOptions = {
  connector: new SimpleConnector,
  autoFetch: false,
  autoSave: true
};

const resourceTwo: IResource = store.get('resource-two');

resourceTwo.newProperty;  // will generate a new empty resource observable
resourceTwo.fetch(); // will update state with whatever's fetched from the external store

resourceTwo.next({
  property1: 'new value'
}); // setting autoSave: true, atomatically triggers resourceTwo.save()

The store creates enhanced RxJS BehaviorSubject proxies which can:

• accessing any property on the resource creates new observables (eg. resourceOne.text instanceof BehaviorSubject). These are created and cached, on-demand on any level.
• resourceOne.obj1.obj2.next(newState) replaces value with a new one and bubbles up the object tree
• resourceOne.update({ text: 'string text2' }) will only replace the text property
• all other BehaviorSubject functionality applies
• fetch and save will sync resource with an external store via a ResourceConnector

Configuration Options

The 'ResourceOptions' can have the following properties

• connector - attaches ResourceConnector instance to be used to persist state (eg. DB, LocalStorage, etc.)
• autoFetch - (boolean, default: false) automatically calls the fetch method on Connector
• autoSave - (boolean, default: false) any call to next or update will atomatically call the save method on the ResourceConnector
• initialState - sets the initial state for the resource