A utility to wrap many copies of a single Redux reducer into a single key-based reducer.
npm install multireducer-meck#multireducer
multireducer is a utility to wrap many copies of a single Redux reducer into a single key-based reducer.
``
npm install --save multireducer
There are times when writing a Redux application where you might find yourself needing multiple copies of the same reducer. For example, you might need more than one list of the same type of object to be displayed. Rather than make a big reducer to handle list A, B, and C, and have action creators either in the form addToB(item) or addToList('B', item), it would be easier to write one "list" reducer, which is easier to write, reason about, and test, with a simpler add(item) API.
However, Redux won't let you do this:
`javascript
import list from './reducers/list';
const reducer = combineReducers({
a: list, // WRONG
b: list, // WRONG
c: list // WRONG
});
`
Each of those reducers is going to respond the same to every action.
This is where multireducer comes in. Multireducer lets you mount the same reducer any number of times in your Redux state tree, as long as you pass the key that you mounted it on to your connected component.
STEP 1: First you will need to wrap the reducer you want to copy.
`javascript
import multireducer from 'multireducer';
import list from './reducers/list';
const reducer = combineReducers({
multireducer: multireducer({ // must be mounted at 'multireducer'
proposed : list,
scheduled : list,
active : list,
complete : list
})
});
`
STEP 2: Now use connectMultireducer() instead of react-redux's connect() to connect your component to the Redux store.
`javascript
import React, {Component, PropTypes} from 'react';
import {connectMultireducer} from 'multireducer';
import {add, remove} from './actions/list';
class ListComponent extends Component {
static propTypes = {
list: PropTypes.array.isRequired
}
render() {
const {add, list, remove} = this.props;
return (
ListComponent = connectMultireducer(
state => ({ list: state.list }),
{add, remove}
)(ListComponent);
export default ListComponent;
`
STEP 3: Pass the appropriate multireducerKey prop to your decorated component.
`javascript`
render() {
return (
Lists
);
}
Wraps many reducers into one, much like Redux's combineReducers() does, except that the reducer that multireducer creates will filter your actions by a multireducerKey, so that the right reducer gets the action. Remember to mount it under multireducer in your reducer tree!
Creates a higher order component decorator, much like react-redux's connect(), that will provide your reducer's state slice, automatically bind your actions to dispatch, and add the needed filter to each of your actions so that they will go to the correct reducer.
##### -mapStateToProps : Function [optional]
> Similar to the mapStateToProps passed to react-redux's connect(), _BUT WITH ONE DIFFERENCE_: :warning: The mapStateToProps given to connect() is given the global state, and the mapStateToProps given to connectMultireducer() is given _only the state slice corresponding to the reducer specified by multireducerKey_. :warning:
#### -multireducerKey : String [required]
> The key to the reducer in the reducers object given to multireducer(). This will limit its state and actions to the corresponding reducer.
The react-redux-universal-hot-example project uses multireducer. See its reducer.js, which combines the plain vanilla counter.js duck, to a multireducer. The CounterButton.js connects to the multireducer, and the Home.js calls with a multireducerKey` prop.