Awesome

Tesserae

What is it?

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, VegaLite and other UI elements like buttons etc.

Status

In active development and used every day in production at Lumber. Tesserae acts as a dashboard to provide overviews over employee utilization, project hours and finances. It also acts as a slack notifier sending daily project summaries to employees.

That said, the current code is sparsely documented.

Demo

A few incompatible changes have landed since the demo code has been pushed. These are minor changes overall but we're not currently focused on maintaining demo data.
An earlier commit should work and provide a similar experience to master.

Try this in your deps.edn and follow the steps below:

lumberdev/tesserae {:git/url "https://github.com/lumberdev/tesserae"
                    :sha     "fcfabb928a44ba72b56c091725c3b564614eca91"}

Run

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

then visit http://localhost:3900

Dev

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.

Extending Tesserae

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))

Status

Used internally in prod at Lumber but also very alpha!

Contribute

• 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!

Thanks

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.

License

Copyright © 2023 Dennis Heihoff, Lumber LLC