feat(datalog-console): respond to datalog-console messages in browser

src/datascript/core.cljc

@@ -2,6 +2,7 @@
   (:refer-clojure :exclude [filter])
   (:require
     [#?(:cljs cljs.reader :clj clojure.edn) :as edn]
+    [datascript.integrations.datalog-console :as datalog-console]
     [datascript.db :as db #?@(:cljs [:refer [FilteredDB]])]
     #?(:clj [datascript.pprint])
     [datascript.pull-api :as dp]
@@ -416,7 +417,9 @@
 (defn conn-from-db
   "Creates a mutable reference to a given immutable database. See [[create-conn]]."
   [db]
-  (atom db :meta { :listeners (atom {}) }))
+  (let [conn (atom db :meta {:listeners (atom {})})]
+    (datalog-console/init! {:conn conn})
+    conn))
 
 
 (defn conn-from-datoms

src/datascript/integrations/datalog_console.cljc

@@ -0,0 +1,20 @@
+(ns datascript.integrations.datalog-console
+  #?(:cljs (:require [goog.object :as gobj]
+                     [goog.labs.userAgent.browser :as user-agent]
+                     [cljs.reader])))
+
+
+(defn init!
+  [{:keys [conn]}]
+  #?(:cljs (when (seq (user-agent/getVersion))
+                 (js/document.documentElement.setAttribute "__datalog-console-remote-installed__" true)
+                 (.addEventListener js/window "message"
+                                    (fn [event]
+                                      (when-let [devtool-message (gobj/getValueByKeys event "data" ":datalog-console.client/devtool-message")]
+                                        (let [msg-type (:type (cljs.reader/read-string devtool-message))]
+                                          (case msg-type
+
+                                            :datalog-console.client/request-whole-database-as-string
+                                            (.postMessage js/window #js {":datalog-console.remote/remote-message" (pr-str @conn)} "*")
+
+                                            nil))))))))