React Collect

Allows the top of your render-tree to collect information from elements in the sub-tree. Whenever the tree rerenders, the collection of information is adjusted to contain only the information from the rendered elements.

This allows to dynamically include only the Redux reducers that are relevant to the current view, for example, which can have benefits for performance or bundle size. It also encourages a more "componentised" architecture.

Usage

import {collect, Collector} from 'react-collect';
import {render} from 'react-dom';
import {createStore} from 'redux';
import reduceReducers from 'reduce-reducers';

const myReducer = (state, {type}) => ({...state, lastAction: type});
const store = createStore (x => x);

// We pass the reducer into collect. Whenever this component is mounted,
// the reducer will be made available to the Collector.
const MyComponent = collect (myReducer) (() => (
  <button onClick={() => store.dispatch ({type: 'MY_ACTION'})}></button>
));

// Whenever the set of reducers changes, we swap out the active reducer.
const onChange = rs => store.replaceReducer (reduceReducers (rs));

render (
  <Collector onChange={onChange}><MyComponent /></Collector>,
  document.getElementById ('app')
);

API

collect :: Any? -⁠> ReactComponent -⁠> ReactComponent

Decorates a component with collection capabilities. Decorated components must have a Collector as one of their ancestors.

When given, the first argument is an item that is always automatically collected whenever the component mounts, and uncollected when the component unmounts.

Alternatively, for more control, you can manually use the collect and uncollect functions that are given to the decorated component as props.

import {collect} from 'react-collect';
import {MyComponent} from './my-component';

export default collect ({message: 'Hello!'}) (MyComponent);

Collector :: ReactComponent

This component wraps your tree and collects the items from all child components that have been decorated with collect.

Expects a single property onChange - the function to call when the collection has changed. The function is called with an array of distinct entries.

import {Collector} from 'react-collect';
import App from './my-app';

const onChange = collection => collection.forEach (() => { /* */ });

export default <Collector onChange={onChange}><App /></Collector>;