Pass context to render in ReactCompositeComponent. Related to #1387

[nhunzaker]

Not a super big deal, but I wanted to put some legs behind #1387.

I'm not really sure this is all that is required, but this change should allow props and state to be passed to the render() method by passing in the component instance:

render({ props, state }) {
    return <p>{ props.thing }</p>
}

[akre54]

You could do something similar with .call and a {props, state} object. Not especially clean, but syntactically similar and wouldn't require a signature change.

I personally would like to see render(props, state) added to encourage pure render functions, but I also realize it might break expectations if the rest of your component methods have to use this.props.foo and this.state.foo.

[nhunzaker]

@akre54 Actually, on the related issue (#1387) there was discussion about render(props, state) being problematic with replaceState and replaceProps. Seeing as how they are now deprecated I wonder if that's a more realistic goal.

[zpao]

cc @sebmarkbage - anything you want to do about this in the short-term?

[sebmarkbage]

Basically, our thinking has been that this should be consistent with life cycle methods (which get nextProps, nextState, nextContext or previousProps, previousState, previousContext and also uses this) and how you do things in callbacks (which uses this).

We've been exploring ways of expressing callbacks in a way that they also receive props, state, context in the same way. We haven't landed on anything there yet though. Therefore the idea was to wait on something here until we know where we're heading with that API.

One design philosophy we have is that there generally shouldn't be two different ways to do the same thing in arbitrarily different ways. That creates bikeshedding and confusion.

I think the next thing we could do is allow constructors to return a ReactElement. This is the stateless function proposal in react-future. Perhaps this is a good start to encouraging pure functions.

[sophiebits]

Closing for now.