Currently, it's a spreadsheet where cells:

1. run user Clojure code async and in parallel
2. reactively re-run when upstream cells update
3. can run on schedule (e.g. "every 5 seconds")
4. can render hiccup and other UI elements like buttons etc.

Run

clojure -X:demo:dev/cljs tesserae.serve/demo

then visit http://localhost:3900

npm install

Start a clojure repl with the :dev/cljs alias. Go to tesserae.serve, load the file. Shadow-cljs should start up. Run (-main) or (mount/start) to boot up the server, db, listeners etc.

Injecting user code into the eval context:
Custom namespaces and bindings can be added on startup using mount args.
The values of namespaces map, if they're symbols, have to be on the classpath and will automatically be required.
The values of the bindings map will be required and resolved if they are fully qualified symbols or otherwise left as their identity.

For example:

(-> (mount/with-args
      {:tesserae.db/dir          "folder-in-project-root/data/datalevin/db"
       :tesserae.eval/namespaces {'walk 'clojure.walk
                                  'my-ns {'my-fn (fn [x] (println :foo x))}}
       :tesserae.eval/bindings   {'println `println
                                  'debug   (fn [& args] (apply println ::dbg args))}})
    (mount/start))

Used internally in prod at Lumber but also very alpha!

• improve code entering experience, e.g. by adding codemirror with clojure mode
• cell functions and UI plugin system. Users should be able to extend Tesserae with their own code.
• UI additions: multiple sheets, search, users, permissions... the whole shebang!

As of this commit Tesserae is a lean 1766 LoC! This made possible largely thanks to Hyperfiddle's Electric, Borkdude's sci and Juji's Datalevin.

Copyright © 2023 Dennis Heihoff, Lumber LLC