This is not to be merged, but opening for discussion. It would be useful to be able to save a snapshot of app-state to be able to restore from later on, either within the same browser session or in a later one.

Current goals:

• Serialise state and reload it within the same browser session
• Serialise state and reload it against the same version of the application, but in a different session.

Out of scope:

• Saving state from remote users and loading it into a debugging build
• Exporting state
• This working on different versions of code.

I found two issues immediately with the serialisation approach I have taken:

• Some objects in app-db are not deserialisable, e.g. deftypes that haven't got a custom printer/reader.
• In the todomvc example, there is a spec for the maps being ordered maps. However an ordered map serialised with prn is indistinguishable from a standard map and will cause a spec exception.

Both of these show that ser/de is likely to be the big blocker for this being a useful feature. I'm interested in hearing about other options here which can handle a wider range of datatypes than EDN.

One possibility is to use Transit and allow users to extend our transit readers and writers. I would probably prefer something more automatic but less compatible, like storing the memory representation and then reading it back. This is likely to be challenging for a variety of reasons though.

Another likely issue is being able to do some sort of pre and post initialisation, e.g. to synchronise localstorage, get new auth tokens, e.t.c.