fix: Remove findDOMNode

[mjpsyapse]

This change removes the deprecated findDOMNode function.

[coveralls]

Coverage increased (+4.9%) to 73.864% when pulling 243c5c5 on mjpsyapse:findDOMNode into 8418bba on react-component:master.

[mjpsyapse]

tl;dr Don't merge this.

I have been exploring the entire antd / react-component ecosystem, and findDOMNode is used heavily, which makes this migration require a lot of untangling, if not rewriting. For example, rc-animate should be replaced with react-transition-group. In general, I'd say that react-components and antd try to wrap existing libraries that do DOM manipulation with react (like rc-align). It will be a large shift to refactor out all this history.

We need to figure out a strategy for moving forward or else antd will be left behind as react adds new features. i.e. no suspense, no concurrent react, and whatever else comes next.

[zombieJ]

This can not get real dom node:

class MyComponent {
  render() {
    return (<div {...this.props} />);
  }
}

findDOMNode will get instance instead and makes getBoundingClientRect failed.

In low level api, findDOMNode seems still necessary since user may not pass real dom ref out.

But for animate level, yes, we have plan to switch to more react way.

[mjpsyapse]

@zombieJ Yes, I agree that this is a breaking change. And I agree that findDOMNode is useful, but if it's deprecated, there should be a plan to remove it. Right?

[zombieJ]

Here are some info by React doc: https://reactjs.org/docs/forwarding-refs.html#forwarding-refs-in-higher-order-components

User should always pass dom with forwardRef and then findDomNode can be removed. But it also makes that if instance do provides some functions breaks. Or may require user use render props return node & ref.
Still thinking of it since it's a hard decision.

[mjpsyapse]

Closing this since it will never get merged.