/state.json endpoint

[aleclarson]

This feature was mentioned in #2, but will be implemented before then.

Here's the original proposal:

Every route has a generated state.json module. For example, you can fetch /foo/state.json to get the client state for the /foo page. This client state contains the routeModuleId and routeParams by default, in addition to any state set by the renderer that generated the page's HTML.

Similar to #1, there will be fetchClientState and applyClientState helpers exported by saus/client, which can be used in your client-side router.

Amendments since then include:

• Omit applyClientState helper for now
• Rename fetchClientState to loadClientState
• State returned by loadClientState is (indefinitely) cached locally
• The initial state included in the page HTML is injected into the cache
• The state.json module works in both SSG and SSR scenarios

Future

Improvements we could make in the future include:

• Special ttl property in state object would define how long to cache it for

[aleclarson]

Implemented in next branch

Instead of using [page]/state.json, we're using [page].html.js