用道具重组

Question

I am trying to get my head around on how recompose works. Although I understand the underlying concept of it I have a problem with using withProps function. If I try using it for decorating each child of a component with additional props it simply fails to work. What I do is:

const decorateChild = withProps({ /* some additional props */ });
// ... later on
{ React.Children.map(this.props.children, decorateChild) }

And it simply doesn't work. I had to do React.cloneElement instead. Could you please help me with that. Here's a sandbox. Please, notice WrappedComponent.js line number 9

EDIT (The code I have problem with...)
so this works fine:

const decorateChild = actions => child =>
  typeof child === "function"
    ? child(actions)
    : React.cloneElement(child, actions);

however I wanted to have it written using recompose. As I said before, if instead of cloneElement I try to do withProps(action)(child) it won't work -> nothing gets rendered. If I try forcing the component to render by withProps(action)(child)() the app crashes.
In general, I wonder how entire WrappedComponent.js could be expressed using recompose. What I dislike about current implementation is how I have to manually manage ref because the underlying component that I'm using (here Wrap ) requires it and this is something I cannot change (3rd party library). I would also love to handle it using recompose

I hope this little explanation makes it a bit more clear what I'm after.

Answer 1

withProps returns a function whose input is another Component (note that child here is the output of a component ie the opaque JS object that represents it), also decorateChild(action) should return the opaque data structure which explains why you need to call it as a function again

Probably the following looks worse than what you did with React.cloneElement but it works:

const decorateChild = actions => child => {
  const Component = (props) => ({ ...child, props: { ...child.props, ...props } })
  return typeof child === "function"
    ? child(actions)
    : withProps(actions)(Component)();
    // this also works
    // : withProps(actions)((props) => React.cloneElement(child, props))();
};

https://codesandbox.io/s/mjx0626wx8