repl-session code to show how Datomic entity API works

repl-sessions/db.clj

@@ -14,23 +14,6 @@
  (db/transact [[:db/retractEntity 17592186045468]]))
 (user/conn)
 
-(db/transact  [{:user/email "[email protected]"
-                :user/handle "laurence.chen"
-                :user/name "Laurence"}])
-
-(db/q
- '[:find
-   [(pull ?e [*]) ...]
-   :where
-   [?e :user/email]]
- (db/db))
-
-(def session-eid 17592186045438)
-
-(db/transact [{:db/id session-eid
-               :session/participants  17592186045458}])
-
-(first (:session/participants (db/entity session-eid)))
 ;; Test transact participants
 
 (def req {:identity {:user/email "ddd"}

repl-sessions/init_db.clj

@@ -0,0 +1,66 @@
+(ns repl-sessions.init-db
+  "Prepare some testing data to transact into db for testing"
+  (:require
+   [co.gaiwan.compass.db :as db]
+   [datomic.api :as d]))
+
+;; Utility
+
+(defn query-session []
+  (db/q
+   '[:find
+     [(pull ?e [*]) ...]
+     :where
+     [?e :session/title "Opening Keynote (TBD)"]]
+   (db/db)))
+
+(defn participants []
+  (db/q
+   '[:find
+     [(pull ?e [*]) ...]
+     :where
+     [?e :user/email]]
+   (db/db)))
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;;        Test Setup Begin
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+;; write participants into the database
+(db/transact [{:user/email "[email protected]"
+               :user/handle "laurence.chen"
+               :user/name "Laurence"}
+              {:user/email "[email protected]"
+               :user/handle "sunnyplexus"
+               :user/name "Arne"}])
+
+;; get the session eid
+(def session-eid (:db/id (first (query-session))))
+
+;; get the eids of participants
+(def p-eids (mapv :db/id (participants)))
+
+(def tx-data (mapv (fn [x] {:db/id session-eid
+                            :session/participants x}) p-eids))
+
+;; relate the pariticipants to the session
+(db/transact tx-data)
+
+;; Simulate the entity access in the frontend
+(def session-entity (db/entity session-eid))
+
+;; Get the first participant's name from the session entity
+(-> session-entity
+    :session/participants
+    first
+    :user/name)
+
+;; Demonstrate the behaviors of Datomic Entity
+
+(type session-entity)
+;; => co.gaiwan.compass.db.munged-entity
+
+(type (-> session-entity
+          :session/participants
+          first))
+;; => co.gaiwan.compass.db.munged-entity