ngrx-store-localstorage

Simple syncing between ngrx store and local storage

Dependencies

ngrx-store-localstorage depends on @ngrx/store and Angular 2.

Usage

npm install ngrx-store-localstorage --save

1. Import compose and combineReducers from @ngrx/store and @ngrx/core/compose
2. Invoke the localStorageSync function after combineReducers, specifying the slices of state you would like to keep synced with local storage.
3. Optionally specify whether to rehydrate this state from local storage as initialState on application bootstrap.
4. Invoke composed function with application reducers as an argument to StoreModule.provideStore.

import { Store, StoreModule } from '@ngrx/store';
import { todos, visibilityFilter } from './reducers';
import { NgModule } from '@angular/core'

@NgModule({
  imports: [
    BrowserModule,
    StoreModule.provideStore(
        compose(
            localStorageSync(['todos']),
            combineReducers
        )({todos, visibilityFilter})
    )
  ]
})
export class MyAppModule {}

API

localStorageSync(keys : any[], rehydrateState : boolean = false, storage: Storage = localStorage) : Reducer

Provide state (reducer) keys to sync with local storage. Optionally specify whether to rehydrate initialState from local storage on bootstrap. Returns a meta-reducer

Arguments

• keys State keys to sync with local storage. The keys can be defined in two different formats:

  • (string[]): array of strings representing the state (reducer) keys. Full state will be synced (e.g. localStorageSync(['todos'])).

  • (object[]): Array of objects where for each object the key represents the state key and the value represents custom serialize/deserialize options. This can be one of the following:

    • an array of properties which should be synced. This allows for the partial state sync (e.g. localStorageSync([{todos: ['name', 'status'] }, ... ]))

    • a reviver function as specified in the JSON.parse documentation

    • an object with properties that specify one or more of the following:

      • serialize: a function that takes a state object and returns a plain json object to pass to json.stringify

      • deserialize: a function that takes that takes the raw JSON from JSON.parse and builds a state object

      • replacer: a replacer function as specified in the JSON.stringify documentation

      • space: the space value to pass JSON.stringify

      • reviver: a reviver function as specified in the JSON.parse documentation

      • filter: an array of properties which should be synced (same format as the stand-along array specified above)

• rehydrateState (boolean? = false): Pull initial state from local storage on startup

• storage (Storage? = localStorage): Specify an object that conforms to the Storage interface to use, this will default localStorage