Redux Persist PouchDB Adapter

Install

npm install redux-persist-pouchdb

Synopsis

import PouchDB from 'pouchdb';

import { createStore } from 'redux';

import { persistStore, persistReducer } from 'redux-persist';
import PouchDBStorage from 'redux-persist-pouchdb';

// the usual PouchDB stuff
PouchDB.plugin( require( 'pouchdb-adapter-memory' ) );
const pouchdb = new PouchDB( 'test', { adapter: 'memory' } );

const storage = new PouchDBStorage(pouchdb);

// your regular reducer
const reducer = function( state={ i: 0 }, action ) {
    if( action.type === 'INC' ) { return { i: 1 + state.i } };
    return state;
}

const persistedReducer = persistReducer(
    { storage, key: 'myRoot' },
    reducer
);

const store = createStore( persistedReducer );

const persistor = persistStore( store, null, () => {
    store.dispatch({ type: INC });
});

Description

This package exports the class PouchDBStorage.

PouchDBStorage

Connect to the PouchDB backend.

const storage = new PouchDBStorage( db_name, { ...pouchDB_options } );

// or

const pouchdb = new PouchDB( db_name, { ...options } );
const storage  = new PouchDBStorage( pouchdb );

The PouchDBStorage object has the following attributes and methods:

db

const doc = storage.db.get({ id: 'my_doc' });

The underlying PouchDB object.

docRevs

Object which keys are the documents known to the object, and the values their current (as far as the PouchDBStorage knows) revision.

async getItem( key )

Retrieves the persisted document based on its key.

async setItem( key, value )

Save the document to PouchDB.

async removeItem( key )

Savagely destroy the document in PouchDB (but doesn't touch the current state in the Redux store).

getAllKeys()

Returns all keys currently used by the PouchDBStorage object.

Recipes

Listening to database changes

It's totally possible to listen to database changes via the db attribute of the PouchDBStorage object. Keep in mind, however, that if you get a new revision from the database, you'll have to update docRevs manually to be sure that the new update from PouchDBStorage won't result in a conflict.

storage.db
    .changes({
        live: true,
        include_docs: true
    })
    .on("change", ({ id, changes, doc }) => {
        // not one of ours, nevermind
        if ( !storage.docRevs[id] ) return;

        // skip if we are the instigators of the change
        if (doc._rev === storage.docRevs[id]) return;

        // manually update the docRevs and tell the
        // store to deal with the change
        storage.docRevs[id] = doc._rev;
        store.dispatch({
            type: "DB_CHANGE",
            payload: doc.doc
        });
    });