smart-wrapper.js

// Have some complicated non-React widgets that manipulate DOM?
// Do they manage a list of DOM elements? Here's how to wrap it
// into a React component so you can "constantly rerender" it.

// A dumb non-react widget that manually manage some DOM node that
// represent a list of items
function NonReactWidget(node) {
  this.node = node;
}

NonReactWidget.prototype = {
  addItem: function(item) {
    // construct a DOM element representing the item
    var domElement = ...;
    this.node.appendChild(domElement);
  }

  removeItem: function(item) {
    // remove the item from the list (need to find it somehow)
  }

  updateItem: function(item) {
    // update the item in the list (need to find it and figure out how
    // to update it, there's probably constraints here already since
    // you weren't using React). You might even be able to just ignore
    // this (with my use case I can, nothing is ever updated)
  }
};

// A React interface. We don't want to carefully call
// `addItem`/`removeItem` ourselves, we want to throw an array of
// items at it like we would with React components. The `Item`
// component is a stub that works with React's vdom system but gives
// us lifecycle events to actually propagate the change into the DOM.

const Item = React.createClass({
  componentDidMount: function() {
    this.props.view.addItem(this.props.item);
  },

  componentWillUnmount: function() {
    this.props.view.removeItem(this.props.item);
  },

  componentWillReceiveProps: function(nextProps) {
    this.props.view.updateItem(nextProps.item);
  }

  render: function() {
    return null;
  }
});

const Items = React.createClass({
  componentDidMount: function() {
    this._view = new NonReactWidget();
  },

  render: function() {
    return dom.ul(
      null,
      // Create a list of `Item` elements, they are stubs that let
      // React do its diffing magic
      dom.li(null, map(this.props.items, item => {
        return Item({ item: item,
                      view: this._view });
      }))
    );
  }
});

React.render(React.createElement(Items, { items: items }),
             mountPoint);