README
@larscom/ngrx-store-storagesync
Highly configurable state syncing between the @ngrx/store
and any implementation of the Storage
interface, like localstorage
or sessionstorage
Supports
- ✓ Exclude deeply nested properties
- ✓ Storage location per feature state, for example:
- feature1 to
sessionStorage
- feature2 to
localStorage
- feature1 to
- ✓ Sync Reactive Forms (additional library)
Demo
You can play arround at https://ngrx-store-storagesync.firebaseapp.com
Dependencies
@larscom/ngrx-store-storagesync
depends on @ngrx/store and Angular
Installation
npm i --save @larscom/ngrx-store-storagesync
Choose the version corresponding to your Angular version
@angular/core | @larscom/ngrx-store-storagesync |
---|---|
>= 12 | >= 13.0.0 |
< 12 | <= 6.3.0 |
Usage
Include storageSyncReducer
in your meta-reducers array in StoreModule.forRoot
import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { StoreModule } from '@ngrx/store';
import { routerReducer } from '@ngrx/router-store';
import { storageSync } from '@larscom/ngrx-store-storagesync';
import * as fromFeature1 from './feature/reducer';
export const reducers: ActionReducerMap<IRootState> = {
router: routerReducer,
feature1: fromFeature1.reducer
};
export function storageSyncReducer(reducer: ActionReducer<IRootState>): ActionReducer<IRootState> {
// provide all feature states within the features array
// features which are not provided, do not get synced
const metaReducer = storageSync<IRootState>({
features: [
// save only router state to sessionStorage
{ stateKey: 'router', storageForFeature: window.sessionStorage },
// exclude key 'success' inside 'auth' and all keys 'loading' inside 'feature1'
{ stateKey: 'feature1', excludeKeys: ['auth.success', 'loading'] }
],
// defaults to localStorage
storage: window.localStorage
});
return metaReducer(reducer);
}
// add storageSyncReducer to metaReducers
const metaReducers: MetaReducer<any>[] = [storageSyncReducer];
@NgModule({
imports: [BrowserModule, StoreModule.forRoot(reducers, { metaReducers })]
})
export class AppModule {}
Configuration
export interface IStorageSyncOptions<T> {
/**
* By default, states are not synced, provide the feature states you want to sync.
*/
features: IFeatureOptions<T>[];
/**
* Provide the storage type to sync the state to, it can be any storage which implements the 'Storage' interface.
*/
storage: Storage;
/**
* Give the state a version. Version will be checked before rehydration.
*
* @examples
* Storage.version = 1 and Config.version = 2 --> Skip hydration
*
* Storage.version = undefined and Config.version = 1 --> Skip hydration
*
* Storage.version = 1 and Config.version = undefined --> Hydrate
*
* Storage.version = 1 and Config.version = 1 --> Hydrate
*/
version?: number;
/**
* Function that gets executed on a storage error
* @param error the error that occurred
*/
storageError?: (error: any) => void;
/**
* Restore last known state from storage on startup
*/
rehydrate?: boolean;
/**
* Serializer for storage keys
* @param key the storage item key
*/
storageKeySerializer?: (key: string) => string;
/**
* Custom state merge function after rehydration (by default it does a deep merge)
* @param state the next state
* @param rehydratedState the state resolved from a storage location
*/
rehydrateStateMerger?: (state: T, rehydratedState: T) => T;
}
export interface IFeatureOptions<T> {
/**
* The name of the feature state to sync
*/
stateKey: string;
/**
* Filter out (ignore) properties that exist on the feature state.
*/
excludeKeys?: string[];
/**
* Provide the storage type to sync the feature state to,
* it can be any storage which implements the 'Storage' interface.
*
* It will override the storage property in StorageSyncOptions
* @see IStorageSyncOptions
*/
storageForFeature?: Storage;
/**
* Sync to storage will only occur when this function returns true
* @param featureState the next feature state
* @param state the next state
*/
shouldSync?: (featureState: unknown, state: T) => boolean;
/**
* Serializer for storage keys (feature state),
* it will override the storageKeySerializer in StorageSyncOptions
* @see IStorageSyncOptions
*
* @param key the storage item key
*/
storageKeySerializerForFeature?: (key: string) => string;
/**
* Serializer for the feature state (before saving to a storage location)
* @param featureState the next feature state
*/
serialize?: (featureState: unknown) => string;
/**
* Deserializer for the feature state (after getting the state from a storage location)
*
* ISO Date objects which are stored as a string gets revived as Date object by default.
* @param featureState the feature state retrieved from a storage location
*/
deserialize?: (featureState: string) => any;
}
Examples
Sync to different storage locations
You can sync to different storage locations per feature state.
export function storageSyncReducer(reducer: ActionReducer<IRootState>) {
return storageSync<IRootState>({
features: [
{ stateKey: 'feature1', storageForFeature: window.sessionStorage }, // to sessionStorage
{ stateKey: 'feature2' } // to localStorage because of 'default' which is set below.
],
storage: window.localStorage // default
})(reducer);
}
Exclude specific properties on state
Prevent specific properties from being synced to storage.
const state: IRootState = {
feature1: {
message: 'hello', // excluded
loading: false,
auth: {
loading: false, // excluded
loggedIn: false,
message: 'hello' // excluded
}
}
};
export function storageSyncReducer(reducer: ActionReducer<IRootState>) {
return storageSync<IRootState>({
features: [{ stateKey: 'feature1', excludeKeys: ['auth.loading', 'message'] }],
storage: window.localStorage
})(reducer);
}
Sync conditionally
Sync state to storage based on a condition.
const state: IRootState = {
checkMe: true, // <---
feature1: {
rememberMe: false, // <---
auth: {
loading: false,
message: 'hello'
}
}
};
export function storageSyncReducer(reducer: ActionReducer<IRootState>) {
return storageSync<IRootState>({
features: [
{
stateKey: 'feature1',
shouldSync: (feature1: any, state: IRootState) => {
return feature1.rememberMe || state.checkMe;
}
}
],
storage: window.localStorage
})(reducer);
}
Serialize state
Override the default serializer for the feature state.
export function storageSyncReducer(reducer: ActionReducer<IRootState>) {
return storageSync<IRootState>({
features: [
{
stateKey: 'feature1',
serialize: (feature1: any) => JSON.stringify(feature1)
}
],
storage: window.localStorage
})(reducer);
}
Deserialize state
Override the default deserializer for the feature state.
export function storageSyncReducer(reducer: ActionReducer<IRootState>) {
return storageSync<IRootState>({
features: [
{
stateKey: 'feature1',
deserialize: (feature1: string) => JSON.parse(feature1)
}
],
storage: window.localStorage
})(reducer);
}
Serialize storage key
Override the default storage key serializer.
export function storageSyncReducer(reducer: ActionReducer<IRootState>) {
return storageSync<IRootState>({
features: [{ stateKey: 'feature1' }],
storageKeySerializer: (key: string) => `abc_${key}`,
storage: window.localStorage
})(reducer);
}
Merge rehydrated state
Override the default rehydrated state merger.
export function storageSyncReducer(reducer: ActionReducer<IRootState>) {
return storageSync<IRootState>({
features: [{ stateKey: 'feature1' }],
rehydrateStateMerger: (state: IRootState, rehydratedState: IRootState) => {
return { ...state, ...rehydratedState };
},
storage: window.localStorage
})(reducer);
}
Sync Reactive Forms
To sync reactive forms
to the store, you can use @larscom/ngrx-store-formsync
It is really easy to setup and you can combine that library with this one.
Head over to @larscom/ngrx-store-formsync on how to configure that library.