Path-reducer NPM

Path reducer

This is a reducer function to modify the app state via path (100% compatible with redux). At this development stage, it only works with immutable-js state objects.

Quick start

import { assert } from 'chai';
import { pathReducer } from 'path-reducer';
import { Immutable } from 'immutable';
import { createStore } from 'redux';

const defaultState = Immutable.fromJS({
    foo: 0,
    bar: {
        boo: 0,
        bla: 0
    }
});
const reducer = (state = defaultState, action) => {
    // Operate with nextState here
    return state;
};
const store = createStore(pathReducer(reducer));
const action = {
    type: 'updateElementInObject',
    meta: ['bar', 'boo'],
    payload: {
        boo: 1
    }
};

store.dispatch(action);
assert.equal(store.getState(), {
    foo: 0,
    bar: {
        boo: 1,
        bla: 0
    }
});

API

pathReducer(reducer)

This is a reducer wrapper that makes your life easier:

const reducer = (state = defaultState, action) {
    // The state here is already parsed
    return state;
};
const store = createStore(pathReducer(reducer));

The pathReducer function will look for an array in meta and an object/array in payload. If this conditions are met, it will try to update the path specified into the supplied state.

SEE CASES.md for an extended list of expample cases.

updateImmutableState(state, action)

This is just a simple reducer. It allows you to setup which parts of your reducer will be updated with path:

import { updateImmutableState } from 'path-reducer';
import { combineReducers, createStore } from 'redux';

const somePartOfTheTree = (state = someDefaultState, action) => {
    switch (action.type) {
        case 'PATH':
            const nextState = updateImmutableState(state, action);
            // Operate with nextState here
            return nextState;
        default:
            return state;
    }
};

const anotherPartOfTheTree = (state = anotherDefaultState, action) => {
    switch (action.type) {
        case 'NO_PATH':
            const nextState = Object.assign({}, state);
            // ... Operate the state
            return nextState;
        default:
            return state;
    }
};

const wholeTree = combineReducers({
    somePartOfTheTree,
    anotherPartOfTheTree,
});

const store = createStore(wholeTree);

It expects an FSA action:

{
    "type": "myApp/myAction",
    "meta": [],
    "payload": { }
}

Note the path must be relative to the suplied path, not to the state path. If you are updating a sub-tree of the state, you should add the corresponding part of the path to the action:

const reducer = (state = defaultState, action) => {
    const newAction = {
        type: action.type,
        meta: ['additional', 'path', 'elements', ...action.path],
        payload: Object.assign({}, action.payload)
    };
    const nextState = updateImmutableState(state, action);
    // Operate with nextState here
    return nextState;
};

License: MIT

The MIT License (MIT)

Copyright (c) 2016 AppFeel

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.