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Meteor React Starter

This is my starter. It contains all the necessary components to achieve the desired feature set, with some boilerplate to implement those settings.

It also demonstrates how to use and set up NPDev:Collections, and easy way to create and wire up offline-first collections with transparent SSR and data over methods.

Features

About SSR and Node Streams

Server Side Rendering (SSR) is tricky with React and Node when you include features like React Helmet, and React Loadable for code splitting. These tools require the entire tree to be rendered in order to extract necessary data like the title of a route (Helmet), or the set of dynamic modules needed to render the current route. There are a few things worth understanding to shed light on why it's so complex.

First, React Loadable. In order to properly render the entire tree for a given route, it's necessary to load all the "Loadables" used in a given route, before the tree is rendered. Otherwise you'll get a bunch of truncated branches which end on Loadable's Loading component. On the server this is easy enough - we can just preload all the Loadables at once, and leave them in memory while the server runs. On the client, we don't want to preload everything though, because that would defeat the point of using Loadable and dynamic-imports - to load only the components we need now (code splitting). To work around that, we must record a list of the Loadables used to render the current route on the server, and pass that on to the client. The client can then take up that list, and preload the minimum set of modules to "hydrate" the HTML it received from the server. If we skip this preloading step, we'll get a "flash of loading". It's also faster to load all the needed components/modules at once than it wold be to load them in serial as needed, which is a great side bonus.

Most of the same consideration applies to React Helmet. We need to render the whole tree for the current route, and record all the uses of Hemlet, then insert those values into the output HTML on the server. Helmet has an additional concern that Loadable does not, in that it must render upstream - Helmet is used to modify tags in the head area of the html page.

With React.renderToString, this is pretty straight forward. The server (Meteor) can render the entire app tree to a string, and then set up it's outputs as needed ahead of time, including the stuff in the head area of the html page for Helmet, then flush everything to the client. With React.renderToNodeStream things are more challenging. We can't know before the tree is flushed to the client which head tags and which Loadables to output, so we have to do some additional work. For Loadables it's easy enough - we can use a stream queue to make sure we don't try to get the list of Loadables until the react stream is complete, then append the necessary code to the output stream. For Helmet it's more tricky. We basically cannot work with streams at all and perfectly generate the elements we need, because we can't rewind a stream which has already been sent to the client.

To get React Helmet to work with streams, we'll cache the Helmet output, and use renderToString for the first pass (empty cache), and only use renderToNodeStream on subsequent passes. We'll accept that sometimes, for a single request when the data has changed, and it has not updated the cache, we'll deliver an outdated title or other meta data (unless we implement some more robust cache invalidation).

You can find an unfinished version of stream support using renderToNodeStream for output instead of a renderToString on the "renderToNodeStream" branch. While the basics are working (including React-Loadable support), it's not finished because there Helmet support (caches) has not been completed.

If you are curious, google "renderToNodeStream react node" and you'll find plenty of posts explaining why you might want to use streams. It may also be true that certain web front end caches (CDNs and WAP) can alleviate the need for this altogether - I'm not sure yet.