Add RenderContext and vnode to PluginRenderContext

[NicoZweifel]

I am unsure if there is any reason not to expose the whole RenderContext to the pluginContext, but I think getting the vnode or at least the type and other context properties would be really helpful for plugin development.

For example for something like styled-components e.g. #927

[adamgreg]

Is this likely to merge? I'm putting together a Fresh project, and trying to use an existing React component library that uses styled-components. I've been trying to write a plugin for SSR, and it looks like I need this extra context to be able to interact with the tree before rendering.

[marvinhagemeister]

@adamgreg I'd love to hear more details. How would the changes in this PR aid with styled-components SSR? From what I can gather from their docs it seems like setting up a virtual stylesheet before rendering, then doing the render and then returning the stylesheet in the fresh plugin options would be the way to go.

[adamgreg]

Hi @marvinhagemeister, thanks for the quick response! I'm new to Fresh and still finding my feet, to be honest, so please forgive me if I have the wrong idea about some of this.

My understanding of their docs is that I need to wrap the tree in a StyleSheetManager component before rendering (either directly, or via sheet.collectStyles()). As the PluginRenderContext that the plugin receives only includes the render method, I don't see an easy way to wrap the tree within the plugin.

At the moment my best guess is that instead of using a plugin I might be able to use _app.tsx to wrap every page in a StyleSheetManager, and handle the sheet in a custom render function I pass to start(). If I do that I'm still not sure how I would access the same ServerStyleSheet instance in both the App function and my custom render function (unless it's safe to use a global variable).

Any help would be gratefully appreciated!