rata

State management through Datascript and Reagent's track mechanism

usage

Rata hooks itself into the transactor of Datascript. So you just need to register it against Datascript's connection. From that point onwards, you should use rata/q! and rata/pull! with the connection. Rata also provides a transact! functions which accepts a sequence of middlewares; middlewares are useful to add extra capabilities like transaction logging, data based effects, etc.

Check the example directory for a working project

(ns example.core
  (:require [reagent.core :as reagent :refer [atom]]
            [datascript.core :as data]
            [hiposfer.rata.core :as rata]))

(def schema {:user/input {:db.unique :db.unique/identity}})

(defn- logger
  [middleware]
  (fn log* [db transaction]
    (let [transaction (middleware db transaction)]
      (apply js/console.log (clj->js transaction))
      transaction)))

;; state is a standard Clojure Atom containing a Datascript DB
(defonce state (rata/listen! (data/create-conn schema)
                             [logger])) ;; middleware chain

(defn example
  []
  (let [click-count @(rata/q! '[:find ?count .
                                :where [?input :user/input "click"]
                                       [?input :click/count ?count]]
                              state)]
    [:div "For each click, you get a greeting :)"
     [:input {:type "button" :value "Click me!"
              ;; rata/transact! usage here instead of data/transact! ------
              :on-click #(rata/transact! state [{:user/input "click"
                                                 :click/count (inc click-count)}])}]
     (for [i (range click-count)]
       ^{:key i}
       [:div "hello " i])]))

(reagent/render-component [example] (. js/document (getElementById "app")))

(defn on-js-reload [])

License

Copyright © 2018

Distributed under LGPLv3