Nifty Snippets

snippets.clj

; https://stackoverflow.com/questions/36032562/extract-values-from-vector-of-maps-conditionally-in-clojure
(map val (filter (comp #{:a} key) (apply concat vector-of-maps)))

; Grab URL from JavaScript window API
(ns awesome.stuff.to.learn
  (:require [cemerick.url :as url]))

(defn [] (:anchor (url/url (-> js/window .-location .-href))))

; (compare-and-swap) function takes four arguments: an entity id, an attribute, an old value, and a new value.
; htps://docs.datomic.com/on-prem/transactions.html#dbfn-cas
(defn update-entity
  [params]
  (let [conn awesome.db.datomic/conn
        db (d/db conn)
        entity-id (Long/parseLong (:entity-id params))
        entity (get-entity db entity-id)]
    {:db-after @(d/transact conn
                            [[:db.fn/cas (:id entity) :entity/name (:name entity) (:entity-name params)]
                             [:db.fn/cas (:user-id entity) :user/email (:user-email entity) (:user-email params)]])}))