1. pages-clients-configuration-transitions.js

import Immutable from 'immutable';
import {put, take} from 'redux-saga/effects';

import {ClientActions, ClientActionTypes} from 'services/clients/transitions';
import {generateFormTransitions} from 'utils/form-transitions';
import translateTransitions from 'utils/translate-transitions';

const initialValues = Immutable.fromJS({
  name: '',
});

const transitions = [
  ...generateFormTransitions({initialValues}),
  {
    name: 'fetchClient',
    * saga({Actions}, {id}) {
      yield put(ClientActions.fetchItem({id}));

      const {type, item} = yield take([
        ClientActionTypes.FETCH_ITEM_SUCCESS,
        ClientActionTypes.FETCH_ITEM_FAILURE,
      ]);

      if (type !== ClientActionTypes.FETCH_ITEM_SUCCESS) return;

      yield put(Actions.loadInputs({inputs: item}));
    },
  },
];

export const initialState = Immutable.fromJS({
  inputs: initialValues,
});

export const {
  Actions,
  ActionTypes,
  reducers,
  saga,
  prefix,
} = translateTransitions({
  prefix: 'pages/clients/configuration',
  transitions,
});

2. form-transitions.js

export const getInputs = (state, {viewPath}) => {
  const path = viewPath.split('/');
  return state.getIn([...path, 'inputs']);
};

export const generateFormTransitions = ({initialValues}) => {
  return [
    {
      name: 'loadInputs',
      reducer(state, {inputs}) {
        return state.set('inputs', state.get('inputs').merge(inputs));
      },
    },
    {
      name: 'changeInput',
      reducer(state, {name, value}) {
        return state.setIn(['inputs', name], value);
      },
    },
    {
      name: 'reset',
      reducer(state) {
        return state.set('inputs', initialValues);
      },
    },
  ];
};