Notes on Clojurescript

clojurescript_notes.cljs

; Clojure strings are Javascript strings
(def s "This is a string")

; Can access Javascript functions, using dot-prefixed notation
(.toUpperCase s)

; To retrieve an object property
(.-length s)

; Javascript supports method-chaining. To accomplish the same in Clojurescript we would nest the function calls, or better still
; we could use the threading macros.
; Alternatively, Clojurescript has a double-dot notation
(.. s (charCodeAt 7) (toString 16) (toUpperCase))

; Property getters and setters
(set! js/newvar 3)

; Javascript objects are created
(js-obj "x" 1 "y" 2)
; Javascript arrays are created
(def arr (array 1 2 3))

; Access properties
(aset js-obj "z" 1)
(aget arr 1) ;=> 2

; Javascript globals are accessed using the js namespace
(js/xxx)

; Javascript constructors i.e. new Date() - by placing a dot after the function
(js/Date.)
(def tmp (js/NameOfClass. "arg1" "arg2"))

; Convert Clojurescript maps to Javascript objects using #js reader macro. Only converts top level
#js {:map {:ima "map"}
     :object #js {:ima "js-obj"}}

; To map between nested Javascript and Clojurescript use js->clj, and clj->js

; References
; 1. http://www.spacjer.com/blog/2014/09/12/clojurescript-javascript-interop/
; 2. https://www.reddit.com/r/Clojure/comments/5ec8kr/lumo_nodebased_clojurescript_repl_has_a_100/
; 3. http://clojurescriptmadeeasy.com/