Add t.ReactChildren to pre-defined types

[jednano]

In lieu of #18 it seems useful to include t.ReactChildren as a pre-defined type. Would you be willing to accept a PR with this inclusion?

[jednano]

Also, I think it may be necessary to include t.ReactNode here, for cases when the children are a single TextNode. For example:

<FooComponent>
    Hello, World!
</FooComponent>

So the final type would be:

export const ReactChildren = t.union([
    t.Nil,
    t.ReactNode,
    t.ReactElement,
    t.list(t.ReactElement)
]);

How does that sound?

[gcanti]

Hi,
Sorry for the delay.

Isn't ReactNode enough for your use case?

import React from 'react';
import ReactDOM from 'react-dom';
import {t, props, ReactNode} from 'tcomb-react'

@props({
  children: t.maybe(ReactNode)
})
class A extends React.Component {
  render() {
    return <div>hello</div>;
  }
}

const mountNode = document.querySelector('#app')

ReactDOM.render(<A />, mountNode); // => ok
ReactDOM.render(<A><div/></A>, mountNode); // => ok
ReactDOM.render(<A><div/><div/></A>, mountNode); // => ok
ReactDOM.render(<A>world</A>, mountNode); // => ok
ReactDOM.render(<A>{null}</A>, mountNode); // => ok
ReactDOM.render(<A><div>{null}</div></A>, mountNode); // => ok
ReactDOM.render(<A><div/>{null}</A>, mountNode); // => KO!

[jednano]

That appears to be working for now. I'll reopen if it presents itself again. Thanks!

[jednano]

@gcanti it looks like this fails when you return false and I presume undefined in children. For example:

<Foo>
    {isBar && (
        <div>baz</div>
    )}
</Foo>

If isBar is false then t.maybe(t.ReactNode) fails with:

Invalid value false supplied to ReactNode.

However, if I don't use tcomb here then React gracefully displays nothing for false values.

I think ReactChildren might be better described as:

const ReactChild = t.union([
  t.ReactNode,
  t.Boolean,
  t.Nil
]);

const ReactChildren = t.maybe(
  t.union([
    ReactChild,
    t.list(ReactChild)
  ])
);

What do you think?

[gcanti]

Released in https://github.com/gcanti/tcomb-react/releases/tag/v0.8.10