usage with redux-persist: persist only some models

[Leooo]

Hello, this addon works great with redux-persist, only I can't manage to persist only a few models - more exactly, I kind of have done it, but I can't manage to populate again seed data on models I haven't persisted when reloading the page.

There are similar issues opened in redux-persist, but it feels like there should be one specific to redux-orm too.

inspired by rt2zz/redux-persist#134 (comment), this works:

//src/configureStore.js

//..
import { persistStore, persistReducer, createTransform } from 'redux-persist'
import omit from 'lodash/omit'
//..

import rootReducer from './redux/reducers';

let blacklistTransform = createTransform(
  (inboundState, key) => {
    if (key === 'session') {
      //from https://github.com/rt2zz/redux-persist/issues/134#issuecomment-427802073
      return omit(inboundState, ['Hint']);
    } else {
      return inboundState;
    }
  },
  (outboundState, key) => {
    if (key === 'session') {
       // maybe could use orm.getDefaultState() instead. Result should be the same
      outboundState.Hint = {
        indexes: {},
        items: [],
        itemsById: {},
        meta: {}
      };
      return outboundState;
    } else {
      return outboundState;
    }
  }
)
const persistConfig = {
    key: 'root',
    storage,
    transforms: [blacklistTransform]
}

const persistedReducer = persistReducer(persistConfig, rootReducer);

Now that's this bit (orm reducer) that doesn't work for me: inspired by #228 (comment), I tried to add another case where the state is not empty but the model creation (Person.seedDatabase()) is not persisted unfortunately. If I remove hasInitializedDB, now it's been created three times. Surely there must be a better way?

import orm from '../models/orm';
import { defaultUpdater } from 'redux-orm/lib/redux';

let hasInitializedDB = false;
//https://github.com/redux-orm/redux-orm/issues/228#issuecomment-419891508
//this was supposed to handle the case of redux-persist returning empty model lists (Hint, for example)
const initializeState = (orm, state) => {
    const noInitialState = !state;
    state = state || orm.getEmptyState();
    const { Person, Hint } = orm.mutableSession(state);
    if (noInitialState) {
      Person.seedDatabase();
    }
    if (!hasInitializedDB) {
      //hasInitializedDB is needed because, despite the `mutableSession` bit,
      //the models creation below don't directly create models in the store - and this is run at least three times before it does
      //yes, this is a dirty hack TODO
      hasInitializedDB = true;
      if (!state.Hint.items.length) Hint.seedDatabase();
    }
    return state;
};

const createReducer = (orm, updater = defaultUpdater) => {
    return (state, action) => {
        // changed from: orm.session(state || orm.getEmptyState());
       // to orm.session(state || initializeState(orm)); and then the below
        const session = orm.session(initializeState(orm, state));
        updater(session, action);
        return session.state;
    };
};
export default createReducer(orm);

Many thanks to anyone who has a working solution for redux-orm persistence to share (I also looked at https://github.com/rt2zz/redux-persist#nested-persists without success)

[PiotrKujawa]

@Leooo there you go, here is what you can do using my package redux-deep-persist
which can be helpful in creating a config for redux-persist.

import { getPersistConfig } from 'redux-deep-persist';

const config = getPersistConfig({
    key: 'root',
    storage: LocalStorage, // whatever storage you use
    blacklist: [
        'a1.b1.c1',  
        'a2.b2.c2',  
        'a3',
        'a4.b4.c4.no.matter.how.deep.you.go'
    ],
    rootReducer, // your root reducer must be also passed here
    ... // any other props from original redux-persist config, omitting the stateReconciler
});